Publications recently added to the Pubs Warehouse

(500 records max)

Geophysical logging and thermal imaging near the Hemphill Road TCE National Priorities List Superfund site near Gastonia, North Carolina

Released March 27, 2017 16:30 EST

2017, Open-File Report 2017-1017

Dominick J. Antolino, Melinda J. Chapman

Borehole geophysical logs and thermal imaging data were collected by the U.S. Geological Survey near the Hemphill Road TCE (trichloroethylene) National Priorities List Superfund site near Gastonia, North Carolina, during August 2014 through February 2015. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, surface geological mapping and borehole geophysical log and thermal imaging data collection, which included the delineation of more than 600 subsurface features (primarily fracture orientations), was completed in five open borehole wells and two private supply bedrock wells. In addition, areas of possible groundwater discharge within a nearby creek downgradient of the study site were determined based on temperature differences between the stream and bank seepage using thermal imagery.

Assessment of conventional oil resources of the East African Rift Province, East Africa, 2016

Released March 27, 2017 14:15 EST

2017, Fact Sheet 2017-3006

Michael E. Brownfield, Christopher J. Schenk, Timothy R. Klett, Tracey J. Mercier, Stephanie B. Gaswirth, Kristen R. Marra, Thomas M. Finn, Phuong A. Le, Heidi M. Leathers-Miller

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 13.4 billion barrels of oil and 4.6 trillion cubic feet of gas in the East African Rift Province of east Africa.

Assessment of continuous oil and gas resources of the Maracaibo Basin Province of Venezuela and Colombia, 2016

Released March 27, 2017 14:15 EST

2017, Fact Sheet 2017-3011

Christopher J. Schenk, Marilyn E. Tennyson, Tracey J. Mercier, Stephanie B. Gaswirth, Kristen R. Marra, Phoung A. Le, Janet K. Pitman, Michael E. Brownfield, Sarah J. Hawkins, Heidi M. Leathers-Miller, Thomas M. Finn, Timothy R. Klett

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean continuous resources of 656 million barrels of oil and 5.7 trillion cubic feet of gas in the Maracaibo Basin Province, Venezuela and Colombia.

Assessment of continuous oil and gas resources of Solimões, Amazonas, and Parnaíba Basin Provinces, Brazil, 2016

Released March 27, 2017 14:15 EST

2017, Fact Sheet 2017-3009

Christopher J. Schenk, Marilyn E. Tennyson, Timothy R. Klett, Thomas M. Finn, Tracey J. Mercier, Sarah J. Hawkins, Stephanie B. Gaswirth, Kristen R. Marra, Michael E. Brownfield, Phuong A. Le, Heidi M. Leathers-Miller

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean continuous resources of 5 billion barrels of oil and 47 trillion cubic feet of gas in the Paleozoic Solimões, Amazonas, and Parnaíba Basin Provinces, Brazil.


Acute sensitivity of a broad range of freshwater mussels to chemicals with different modes of toxic action

Released March 27, 2017 00:00 EST

2017, Environmental Toxicology and Chemistry (36) 786-796

Ning Wang, Chris D. Ivey, Christopher G. Ingersoll, William G. Brumbaugh, David Alvarez, Edward J. Hammer, Candice R. Bauer, Tom Augspurger, Sandy Raimondo, M.Christopher Barnhart

Freshwater mussels, one of the most imperiled groups of animals in the world, are generally underrepresented in toxicity databases used for the development of ambient water quality criteria and other environmental guidance values. Acute 96-h toxicity tests were conducted to evaluate the sensitivity of 5 species of juvenile mussels from 2 families and 4 tribes to 10 chemicals (ammonia, metals, major ions, and organic compounds) and to screen 10 additional chemicals (mainly organic compounds) with a commonly tested mussel species, fatmucket (Lampsilis siliquoidea). In the multi-species study, median effect concentrations (EC50s) among the 5 species differed by a factor of ≤2 for chloride, potassium, sulfate, and zinc; a factor of ≤5 for ammonia, chromium, copper, and nickel; and factors of 6 and 12 for metolachlor and alachlor, respectively, indicating that mussels representing different families or tribes had similar sensitivity to most of the tested chemicals, regardless of modes of action. There was a strong linear relationship between EC50s for fatmucket and the other 4 mussel species across the 10 chemicals (r2 = 0.97, slope close to 1.0), indicating that fatmucket was similar to other mussel species; thus, this commonly tested species can be a good surrogate for protecting other mussels in acute exposures. The sensitivity of juvenile fatmucket among different populations or cultured from larvae of wild adults and captive-cultured adults was also similar in acute exposures to copper or chloride, indicating captive-cultured adult mussels can reliably be used to reproduce juveniles for toxicity testing. In compiled databases for all freshwater species, 1 or more mussel species were among the 4 most sensitive species for alachlor, ammonia, chloride, potassium, sulfate, copper, nickel, and zinc; therefore, the development of water quality criteria and other environmental guidance values for these chemicals should reflect the sensitivity of mussels. In contrast, the EC50s of fatmucket tested in the single-species study were in the high percentiles (>75th) of species sensitivity distributions for 6 of 7 organic chemicals, indicating mussels might be relatively insensitive to organic chemicals in acute exposures.

The effect of lithology on valley width, terrace distribution, and coarse sediment provenance in a tectonically stable catchment with flat-lying stratigraphy

Released March 27, 2017 00:00 EST

2017, Earth Surface Processes and Landforms

Amanda Keen-Zebert, Mark R. Hudson, Stephanie L. Shepherd, Evan A. Thaler

How rock resistance or erodibility affects fluvial landforms and processes is an outstanding question in geomorphology that has recently garnered attention owing to the recognition that the erosion rates of bedrock channels largely set the pace of landscape evolution. In this work, we evaluate valley width, terrace distribution, and sediment provenance in terms of reach scale variation in lithology in the study reach and discuss the implications for landscape evolution in a catchment with relatively flat2 lying stratigraphy and very little uplift. A reach of the 21 Buffalo National River in Arkansas was partitioned into lithologic reaches and the mechanical and chemical resistance of the main lithologies making up the catchment was measured. Valley width and the spatial distribution of terraces were compared among the different lithologic reaches. The surface grain size and provenance of coarse (2-90 mm) sediment of both modern gravel bars and older terrace deposits were measured and defined. The results demonstrate a strong impact of lithology upon valley width, terrace distribution, and coarse sediment provenance and therefore, upon landscape evolution processes. Channel down-cutting through different lithologies creates variable patterns of resistance across catchments and continents. Particularly in post-tectonic and nontectonic landscapes, the variation in resistance that arises from the exhumation of different rocks in channel longitudinal profiles can impact local base levels, initiating responses that can be propagated through channel networks. The rate at which that response is transmitted through channels is potentially amplified and/or mitigated by differences between the resistance of channel beds and sediment loads. In the study 36 reach, variation in lithologic resistance influences the prevalence of lateral and vertical 37 processes, thus producing a spatial pattern of terraces that reflects rock type rather than 38 climate, regional base level change, or hydrologic variability.

Integrating puffing and explosions in a general scheme for Strombolian-style activity

Released March 27, 2017 00:00 EST

2017, Journal of Geophysical Research B: Solid Earth

Damien Gaudin, Jacopo Taddeucci, Piergiorgio Scarlato, Elisabetta del Bello, Tullio Ricci, Tim Orr, Bruce Houghton, Andrew J. L. Harris, Sandro Rao, Augusto Bucci

Strombolian eruptions are among the most common subaerial styles of explosive volcanism worldwide. Distinctive features of each volcano lead to a correspondingly wide range of variations of magnitude and erupted products, but most papers focus on a single type of event at a single volcano. Here, in order to emphasize the common features underlying this diversity of styles, we scrutinize a database from 35 different erupting vents, including 21 thermal infrared videos from Stromboli (Italy), Etna (Italy), Yasur (Vanuatu), and Batu Tara (Indonesia), from puffing, through rapid explosions to normal explosions, with variable ejection parameters and relative abundance of gas, ash, and bombs. Using field observations and high-speed thermal infrared videos processed by a new algorithm, we identify the distinguishing characteristics of each type of activity and how they may relate and interact. In particular, we record that ash-poor normal explosions may be preceded and followed by the onset or the increase of the puffing activity, while ash-rich explosions are emergent, i.e., with inflation of the free surface followed directly by emission of increasingly large gas pockets. Overall, we see that all Strombolian activities form a continuum arising from a common mechanism and are modulated by the combination of two well-established controls: (1) the length of the bursting gas pocket with respect to the vent diameter and (2) the presence and thickness of a high-viscosity layer in the uppermost part of the volcanic conduit.

Kansas Water Science Center bookmark

Released March 27, 2017 00:00 EST

2017, General Information Product 173

U.S. Geological Survey

The U.S. Geological Survey Kansas Water Science Center has collected and interpreted hydrologic information in Kansas since 1895. Data collected include streamflow and gage height, reservoir content, water quality and water quantity, suspended sediment, and groundwater levels. Interpretative hydrologic studies are completed on national, regional, statewide, and local levels and cooperatively funded through more than 40 partnerships with these agencies. The U.S. Geological Survey provides impartial scientific information to describe and understand the health of our ecosystems and environment; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life. These collected data are in the National Water Information System, and all results are documented in reports that also are online at Follow the USGS Kansas Water Science Center on Twitter for the most recent updates and other information:

Bathymetry data collected in October 2014 from Fire Island, New York—The wilderness breach, shoreface, and bay

Released March 24, 2017 17:30 EST

2017, Data Series 1034

Timothy R. Nelson, Jennifer L. Miselis, Cheryl J. Hapke, Owen T. Brenner, Rachel E. Henderson, Billy J. Reynolds, Kathleen E. Wilson

Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, conducted a bathymetric survey of Fire Island, New York, from October 5 to 10, 2014. The U.S. Geological Survey is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the wilderness breach, which formed in October 2012 during Hurricane Sandy, as part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry data were collected, using single-beam echo sounders and global positioning systems mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach, Fire Island Inlet, Narrow Bay, and Great South Bay east of Nicoll Bay. Additional bathymetry and elevation data were collected using backpack and wheel-mounted global positioning systems along the subaerial beach (foreshore and backshore), flood shoals, and shallow channels within the wilderness breach and adjacent shoreface.

Modeling nonbreeding distributions of shorebirds and waterfowl in response to climate change

Released March 24, 2017 00:00 EST

2017, Ecology and Evolution (7) 1497-1513

Gordon Reese, Susan Skagen

To identify areas on the landscape that may contribute to a robust network of conservation areas, we modeled the probabilities of occurrence of several en route migratory shorebirds and wintering waterfowl in the southern Great Plains of North America, including responses to changing climate. We predominantly used data from the eBird citizen-science project to model probabilities of occurrence relative to land-use patterns, spatial distribution of wetlands, and climate. We projected models to potential future climate conditions using five representative general circulation models of the Coupled Model Intercomparison Project 5 (CMIP5). We used Random Forests to model probabilities of occurrence and compared the time periods 1981–2010 (hindcast) and 2041–2070 (forecast) in “model space.” Projected changes in shorebird probabilities of occurrence varied with species-specific general distribution pattern, migration distance, and spatial extent. Species using the western and northern portion of the study area exhibited the greatest likelihoods of decline, whereas species with more easterly occurrences, mostly long-distance migrants, had the greatest projected increases in probability of occurrence. At an ecoregional extent, differences in probabilities of shorebird occurrence ranged from −0.015 to 0.045 when averaged across climate models, with the largest increases occurring early in migration. Spatial shifts are predicted for several shorebird species. Probabilities of occurrence of wintering Mallards and Northern Pintail are predicted to increase by 0.046 and 0.061, respectively, with northward shifts projected for both species. When incorporated into partner land management decision tools, results at ecoregional extents can be used to identify wetland complexes with the greatest potential to support birds in the nonbreeding season under a wide range of future climate scenarios.

Assessment of a strain 19 brucellosis vaccination program in elk

Released March 24, 2017 00:00 EST

2017, Wildlife Society Bulletin

Eric J. Maichak, Brandon M. Scurlock, Paul C. Cross, Jared D. Rogerson, William H. Edwards, Benjamin Wise, Scott G. Smith, Terry J. Kreeger

Zoonotic diseases in wildlife present substantial challenges and risks to host populations, susceptible domestic livestock populations, and affected stakeholders. Brucellosis, a disease caused by the bacterium Brucella abortus, is endemic among elk (Cervus canadensis) attending winter feedgrounds and adjacent areas of western Wyoming, USA. To minimize transmission of brucellosis from elk to elk and elk to livestock, managers initiated a B. abortus strain 19 ballistic vaccination program in 1985. We used brucellosis prevalence (1971–2015) and reproductive outcome (2006–2015) data collected from female elk attending feedgrounds to assess efficacy of the strain 19 program while controlling for potentially confounding factors such as site and age. From our generalized linear models, we found that seroprevalence of brucellosis was 1) not lower following inception of vaccination; 2) not inversely associated with proportion of juveniles vaccinated over time; 3) not inversely associated with additional yearlings and adults vaccinated over time; and 4) associated more with feeding end-date than proportion of juveniles vaccinated. Using vaginal implant transmitters in adult females that were seropositive for brucellosis, we found little effect of vaccination coverage at reducing reproductive failures (i.e., abortion or stillbirth). Because we found limited support for efficacy of the strain 19 program, we support research to develop an oral vaccine and suggest that continuing other spatio-temporal management actions will be most effective to minimize transmission of brucellosis and reduce dependency of elk on supplemental winter feeding.

Range expansion by Passer montanus in North America

Released March 24, 2017 00:00 EST

2017, Biological Invasions (19) 5-9

J.L. Burnett, C.P. Roberts, Craig R. Allen, M.B. Brown, M.P. Moulton

Passer montanus became established in a small area of central North America following its introduction in 1870. P. montanus underwent minimal range expansion in the first 100 years following introduction. However, the North American population of P. montanus is now growing in size and expanding in geographic distribution, having expanded approximately 125 km to the north by 1970. We quantify the distance of spread by P. montanus from its introduction site in the greater St. Louis, Missouri-Illinois, USA area, using distributional (presence) data from the National Audubon Society Christmas Bird Count surveys for the period of 1951 to 2014. Linear regressions of the average annual range center of P. montanus confirmed significant shifts to the north at a rate of 3.3 km/year (P < 0.001) km/year. Linear regressions of the linear and angular distance of range center indicates significant northern movement (change in angle of mean range center; P < 0.001) since 1951. Our results quantify the extent of a northward range expansion, and suggesting a probable spread of this species northward.

Flood effects provide evidence of an alternate stable state from dam management on the Upper Missouri River

Released March 24, 2017 00:00 EST

2017, River Research and Applications

Katherine Skalak, Adam J. Benthem, Cliff R. Hupp, Edward R. Schenk, Joel M. Galloway, Rochelle A. Nustad

We examine how historic flooding in 2011 affected the geomorphic adjustments created by dam regulation along the approximately 120 km free flowing reach of the Upper Missouri River bounded upstream by the Garrison Dam (1953) and downstream by Lake Oahe Reservoir (1959) near the City of Bismarck, ND, USA. The largest flood since dam regulation occurred in 2011. Flood releases from the Garrison Dam began in May 2011 and lasted until October, peaking with a flow of more than 4200 m3 s−1. Channel cross-section data and aerial imagery before and after the flood were compared with historic rates of channel change to assess the relative impact of the flood on the river morphology. Results indicate that the 2011 flood maintained trends in island area with the loss of islands in the reach just below the dam and an increase in island area downstream. Channel capacity changes varied along the Garrison Segment as a result of the flood. The thalweg, which has been stable since the mid-1970s, did not migrate. And channel morphology, as defined by a newly developed shoaling metric, which quantifies the degree of channel braiding, indicates significant longitudinal variability in response to the flood. These results show that the 2011 flood exacerbates some geomorphic trends caused by the dam while reversing others. We conclude that the presence of dams has created an alternate geomorphic and related ecological stable state, which does not revert towards pre-dam conditions in response to the flood of record. This suggests that management of sediment transport dynamics as well as flow modification is necessary to restore the Garrison Segment of the Upper Missouri River towards pre-dam conditions and help create or maintain habitat for endangered species. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Effects of impervious area and BMP implementation and design on storm runoff and water quality in eight small watersheds

Released March 24, 2017 00:00 EST

2017, Journal of the American Water Resources Association

Brent T. Aulenbach, Mark N. Landers, Jonathan W. Musser, Jaime A. Painter

The effects of increases in effective impervious area (EIA) and the implementation of water quality protection designed detention pond best management practices (BMPs) on storm runoff and stormwater quality were assessed in Gwinnett County, Georgia, for the period 2001-2008. Trends among eight small watersheds were compared, using a time trend study design. Significant trends were detected in three storm hydrologic metrics and in five water quality constituents that were adjusted for variability in storm characteristics and climate. Trends in EIA ranged from 0.10 to 1.35, and changes in EIA treated by BMPs ranged from 0.19 to 1.32; both expressed in units of percentage of drainage area per year. Trend relations indicated that for every 1% increase in watershed EIA, about 2.6, 1.1, and 1.5% increases in EIA treated by BMPs would be required to counteract the effects of EIA added to the watersheds on peak streamflow, stormwater yield, and storm streamflow runoff, respectively. Relations between trends in EIA, BMP implementation, and water quality were counterintuitive. This may be the result of (1) changes in constituent inputs in the watersheds, especially downstream of areas treated by BMPs; (2) BMPs may have increased the duration of stormflow that results in downstream channel erosion; and/or (3) spurious relationships between increases in EIA, BMP implementation, and constituent inputs with development rates.

County-level estimates of nitrogen and phosphorus from animal manure for the conterminous United States, 2007 and 2012

Released March 24, 2017 00:00 EST

2017, Open-File Report 2017-1021

JoAnn M. Gronberg, Terri L. Arnold

County-level estimates of nitrogen and phosphorus inputs from animal manure for the conterminous United States were calculated from animal population inventories in the 2007 and 2012 Census of Agriculture, using previously published methods. These estimates of non-point nitrogen and phosphorus inputs from animal manure were compiled in support of the U.S. Geological Survey’s National Water-Quality Assessment Project of the National WaterQuality Program and are needed to support national-scale investigations of stream and groundwater water quality. The estimates published in this report are comparable with older estimates which can be compared to show changes in nitrogen and phosphorus inputs from manure over time.

Use of multiple age tracers to estimate groundwater residence times and long-term recharge rates in arid southern Oman

Released March 24, 2017 00:00 EST

2016, Applied Geochemistry (74) 67-83

Th. Müller, K. Osenbrück, G. Strauch, S. Pavetich, K.-S. Al-Mashaikhi, C. Herb, S. Merchel, G. Rugel, W. Aeschbach, Ward E. Sanford

Multiple age tracers were measured to estimate groundwater residence times in the regional aquifer system underlying southwestern Oman. This area, known as the Najd, is one of the most arid areas in the world and is planned to be the main agricultural center of the Sultanate of Oman in the near future. The three isotopic age tracers 4He, 14C and 36Cl were measured in waters collected from wells along a line that extended roughly from the Dhofar Mountains near the Arabian Sea northward 400 km into the Empty Quarter of the Arabian Peninsula. The wells sampled were mostly open to the Umm Er Radhuma confined aquifer, although, some were completed in the mostly unconfined Rus aquifer. The combined results from the three tracers indicate the age of the confined groundwater is < 40 ka in the recharge area in the Dhofar Mountains, > 100 ka in the central section north of the mountains, and up to and > one Ma in the Empty Quarter. The 14C data were used to help calibrate the 4He and 36Cl data. Mixing models suggest that long open boreholes north of the mountains compromise 14C-only interpretations there, in contrast to 4He and 36Cl calculations that are less sensitive to borehole mixing. Thus, only the latter two tracers from these more distant wells were considered reliable. In addition to the age tracers, δ2H and δ18O data suggest that seasonal monsoon and infrequent tropical cyclones are both substantial contributors to the recharge. The study highlights the advantages of using multiple chemical and isotopic data when estimating groundwater travel times and recharge rates, and differentiating recharge mechanisms.

Downstream passage and impact of turbine shutdowns on survival of silver American Eels at five hydroelectric dams on the Shenandoah River

Released March 24, 2017 00:00 EST

2016, Transactions of the American Fisheries Society (145) 964-976

Sheila Eyler, Stuart Welsh, David Smith, Mary Rockey

Hydroelectric dams impact the downstream migrations of silver American Eels Anguilla rostrata via migratory delays and turbine mortality. A radiotelemetry study of American Eels was conducted to determine the impacts of five run-of-the-river hydroelectric dams located over a 195-km stretch of the Shenandoah River, Virginia–West Virginia, during fall 2007–summer 2010. Overall, 96 radio-tagged individuals (mean TL = 85.4 cm) migrated downstream past at least one dam during the study. Most American Eels passed dams relatively quickly; over half (57.9%) of the dam passage events occurred within 1 h of reaching a dam, and most (81.3%) occurred within 24 h of reaching the dam. Two-thirds of the dam passage events occurred via spill, and the remaining passage events were through turbines. Migratory delays at dams were shorter and American Eels were more likely to pass via spill over the dam during periods of high river discharge than during low river discharge. The extent of delay in migration did not differ between the passage routes (spill versus turbine). Twenty-eight American Eels suffered turbine-related mortality, which occurred at all five dams. Mortality rates for eels passing through turbines ranged from 15.8% to 40.7% at individual dams. Overall project-specific mortality rates (with all passage routes combined) ranged from 3.0% to 14.3%. To protect downstream-migrating American Eels, nighttime turbine shutdowns (1800–0600 hours) were implemented during September 15–December 15. Fifty percent of all downstream passage events in the study occurred during the turbine shutdown period. Implementation of the seasonal turbine shutdown period reduced cumulative mortality from 63.3% to 37.3% for American Eels passing all five dams. Modifying the turbine shutdown period to encompass more dates in the spring and linking the shutdowns to environmental conditions could provide greater protection to downstream-migrating American Eels.

A comparison of observed and predicted ground motions from the 2015 MW7.8 Gorkha, Nepal, earthquake

Released March 24, 2017 00:00 EST

2016, Natural Hazards (84) 1661-1684

Susan E. Hough, Stacey S. Martin, V. Gahalaut, A. Joshi, M. Landes, R. Bossu

We use 21 strong motion recordings from Nepal and India for the 25 April 2015 moment magnitude (MW) 7.8 Gorkha, Nepal, earthquake together with the extensive macroseismic intensity data set presented by Martin et al. (Seism Res Lett 87:957–962, 2015) to analyse the distribution of ground motions at near-field and regional distances. We show that the data are consistent with the instrumental peak ground acceleration (PGA) versus macroseismic intensity relationship developed by Worden et al. (Bull Seism Soc Am 102:204–221, 2012), and use this relationship to estimate peak ground acceleration from intensities (PGAEMS). For nearest-fault distances (RRUP < 200 km), PGAEMS is consistent with the Atkinson and Boore (Bull Seism Soc Am 93:1703–1729, 2003) subduction zone ground motion prediction equation (GMPE). At greater distances (RRUP > 200 km), instrumental PGA values are consistent with this GMPE, while PGAEMS is systematically higher. We suggest the latter reflects a duration effect whereby effects of weak shaking are enhanced by long-duration and/or long-period ground motions from a large event at regional distances. We use PGAEMS values within 200 km to investigate the variability of high-frequency ground motions using the Atkinson and Boore (Bull Seism Soc Am 93:1703–1729, 2003) GMPE as a baseline. Across the near-field region, PGAEMS is higher by a factor of 2.0–2.5 towards the northern, down-dip edge of the rupture compared to the near-field region nearer to the southern, up-dip edge of the rupture. Inferred deamplification in the deepest part of the Kathmandu valley supports the conclusion that former lake-bed sediments experienced a pervasive nonlinear response during the mainshock (Dixit et al. in Seismol Res Lett 86(6):1533–1539, 2015; Rajaure et al. in Tectonophysics, 2016. Ground motions were significantly amplified in the southern Gangetic basin, but were relatively low in the northern basin. The overall distribution of ground motions and damage during the Gorkha earthquake thus reflects a combination of complex source, path, and site effects. We also present a macroseismic intensity data set and analysis of ground motions for the MW7.3 Dolakha aftershock on 12 May 2015, which we compare to the Gorkha mainshock and conclude was likely a high stress-drop event.

Decreased runoff response to precipitation, Little Missouri River Basin, northern Great Plains, USA

Released March 23, 2017 00:00 EST

2017, Journal of the American Water Resources Association

Eleanor R. Griffin, Jonathan M. Friedman

High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri River Basin and identified differences in the runoff response to precipitation for the period 1976-2012 compared to 1939-1975 (n = 37 years in both cases). Computed mean values for the second half of the record showed little change (<5%) in annual or growing season precipitation, but average annual runoff at the basin outlet decreased by 22%, with 66% of the reduction in flow occurring during the growing season. Our results show a statistically significant (< 0.10) 27% decrease in the annual runoff response to precipitation (runoff ratio). Surface-water withdrawals for various uses appear to account for <12% of the reduction in average annual flow volume, and we found no published or reported evidence of substantial flow reduction caused by groundwater pumping in this basin. Results of our analysis suggest that increases in monthly average maximum and minimum temperatures, including >1°C increases in January through March, are the dominant driver of the observed decrease in runoff response to precipitation in the Little Missouri River Basin.

Channel mapping river miles 29–62 of the Colorado River in Grand Canyon National Park, Arizona, May 2009

Released March 23, 2017 00:00 EST

2017, Open-File Report 2017-1030

Matt Kaplinski, Joseph E. Hazel Jr., Paul E. Grams, Keith Kohl, Daniel D. Buscombe, Robert B. Tusso

Bathymetric, topographic, and grain-size data were collected in May 2009 along a 33-mi reach of the Colorado River in Grand Canyon National Park, Arizona. The study reach is located from river miles 29 to 62 at the confluence of the Colorado and Little Colorado Rivers. Channel bathymetry was mapped using multibeam and singlebeam echosounders, subaerial topography was mapped using ground-based total-stations, and bed-sediment grain-size data were collected using an underwater digital microscope system. These data were combined to produce digital elevation models, spatially variable estimates of digital elevation model uncertainty, georeferenced grain-size data, and bed-sediment distribution maps. This project is a component of a larger effort to monitor the status and trends of sand storage along the Colorado River in Grand Canyon National Park. This report documents the survey methods and post-processing procedures, digital elevation model production and uncertainty assessment, and procedures for bed-sediment classification, and presents the datasets resulting from this study.

Bull trout (Salvelinus confluentus) telemetry and associated habitat data collected in a geodatabase from the upper Boise River, southwestern Idaho

Released March 23, 2017 00:00 EST

2017, Data Series 1042

Dorene E. MacCoy, Zachary M. Shephard, Joseph R. Benjamin, Dmitri T. Vidergar, Anthony F. Prisciandaro

Bull trout (Salvelinus confluentus), listed as threatened under the Endangered Species Act, are among the more thermally sensitive of coldwater species in North America. The Boise River upstream of Arrowrock Dam in southwestern Idaho (including Arrowrock Reservoir) provides habitat for one of the southernmost populations of bull trout. The presence of the species in Arrowrock Reservoir poses implications for dam and reservoir operations. From 2011 to 2014, the Bureau of Reclamation and the U.S. Geological Survey collected fish telemetry data to improve understanding of bull trout distribution and movement in Arrowrock Reservoir and in the upper Boise River tributaries. The U.S. Geological Survey compiled the telemetry (fish location) data, along with reservoir elevation, river discharge, precipitation, and water-quality data in a geodatabase. The geodatabase includes metadata compliant with Federal Geographic Data Committee content standards. The Bureau of Reclamation plans to incorporate the data in a decision‑support tool for reservoir management.

Estimating current and future streamflow characteristics at ungaged sites, central and eastern Montana, with application to evaluating effects of climate change on fish populations

Released March 23, 2017 00:00 EST

2017, Scientific Investigations Report 2017-5002

Roy Sando, Katherine J. Chase

A common statistical procedure for estimating streamflow statistics at ungaged locations is to develop a relational model between streamflow and drainage basin characteristics at gaged locations using least squares regression analysis; however, least squares regression methods are parametric and make constraining assumptions about the data distribution. The random forest regression method provides an alternative nonparametric method for estimating streamflow characteristics at ungaged sites and requires that the data meet fewer statistical conditions than least squares regression methods.

Random forest regression analysis was used to develop predictive models for 89 streamflow characteristics using Precipitation-Runoff Modeling System simulated streamflow data and drainage basin characteristics at 179 sites in central and eastern Montana. The predictive models were developed from streamflow data simulated for current (baseline, water years 1982–99) conditions and three future periods (water years 2021–38, 2046–63, and 2071–88) under three different climate-change scenarios. These predictive models were then used to predict streamflow characteristics for baseline conditions and three future periods at 1,707 fish sampling sites in central and eastern Montana. The average root mean square error for all predictive models was about 50 percent. When streamflow predictions at 23 fish sampling sites were compared to nearby locations with simulated data, the mean relative percent difference was about 43 percent. When predictions were compared to streamflow data recorded at 21 U.S. Geological Survey streamflow-gaging stations outside of the calibration basins, the average mean absolute percent error was about 73 percent.

Estimated dissolved-solids loads and trends at selected streams in and near the Uinta Basin, Utah, Water Years 1989–2013

Released March 23, 2017 00:00 EST

2017, Scientific Investigations Report 2017-5004

Susan A. Thiros

The U.S. Geological Survey (USGS), in cooperation with the Colorado River Basin Salinity Control Forum, studied trends in dissolved-solids loads at selected sites in and near the Uinta Basin, Utah. The Uinta Basin study area includes the Duchesne River Basin and the Middle Green River Basin in Utah from below Flaming Gorge Reservoir to the town of Green River.

Annual dissolved-solids loads for water years (WY) 1989 through 2013 were estimated for 16 gaging stations in the study area using streamflow and water-quality data from the USGS National Water Information System database. Eight gaging stations that monitored catchments with limited or no agricultural land use (natural subbasins) were used to assess loads from natural sources. Four gaging stations that monitored catchments with agricultural land in the Duchesne River Basin were used to assess loads from agricultural sources. Four other gaging stations were included in the dissolved-solids load and trend analysis to help assess the effects of agricultural areas that drain to the Green River in the Uinta Basin, but outside of the Duchesne River Basin.

Estimated mean annual dissolved-solids loads for WY 1989–2013 ranged from 1,520 tons at Lake Fork River above Moon Lake, near Mountain Home, Utah (UT), to 1,760,000 tons at Green River near Green River, UT. The flow-normalized loads at gaging stations upstream of agricultural activities showed no trend or a relatively small change. The largest net change in modeled flow-normalized load was -352,000 tons (a 17.8-percent decrease) at Green River near Green River, UT.
Annual streamflow and modeled dissolved-solids loads at the gaging stations were balanced between upstream and downstream sites to determine how much water and dissolved solids were transported to the Duchesne River and a section of the Green River, and how much was picked up in each drainage area. Mass-balance calculations of WY 1989–2013 mean annual dissolved-solids loads at the studied sites show that Green River near Jensen, UT, accounts for 64 percent of the load in the river at Green River, UT, while the Duchesne River and White River contribute 10 and 13 percent, respectively.

Annual streamflow and modeled dissolved-solids loads at the gaging stations were balanced between upstream and downstream sites to determine how much water and dissolved solids were transported to the Duchesne River and a section of the Green River, and how much was picked up in each drainage area. Mass-balance calculations of WY 1989–2013 mean annual dissolved-solids loads at the studied sites show that Green River near Jensen, UT, accounts for 64 percent of the load in the river at Green River, UT, while the Duchesne River and White River contribute 10 and 13 percent, respectively.

The flow-normalized dissolved-solids loads estimated at Duchesne River near Randlett, UT, and White River near Watson, UT, decreased by 68,000 and 55,300 tons, or 27.8 and 20.8 percent respectively, when comparing 1989 to 2013. The drainage basins for both rivers have undergone salinity-control projects since the early 1980s to reduce the dissolved-solids load entering the Colorado River. Approximately 19 percent of the net change in flow-normalized load at Green River at Green River, UT, is from changes in load modeled at Duchesne River near Randlett, UT, and 16 percent from changes in load modeled at White River near Watson, UT. The net change in flow-normalized load estimated at Green River near Greendale, UT, for WY 1989–2013 accounts for about 45 percent of the net change estimated at Green River at Green River, UT.

Mass-balance calculations of WY 1989–2013 mean annual dissolved-solids loads at the studied sites in the Duchesne River Basin show that 75,400 tons or 44 percent of the load at the Duchesne River near Randlett, UT, gaging station was not accounted for at any of the upstream gages. Most of this unmonitored load is derived from tributary inflow, groundwater discharge, unconsumed irrigation water, and irrigation tail water.

A mass balance of WY 1989–2013 flow-normalized loads estimated at sites in the Duchesne River Basin indicates that the flow-normalized load of unmonitored inflow to the Duchesne River between the Myton and Randlett gaging stations decreased by 38 percent. The total net decrease in flow-normalized load calculated for unmonitored inflow in the drainage basin accounts for 94 percent of the decrease in WY 1989–2013 flow-normalized load modeled at the Duchesne River near Randlett, UT, gaging station. Irrigation improvements in the drainage basin have likely contributed to the decrease in flow-normalized load.

Reductions in dissolved-solids load estimated by the Natural Resources Conservation Service (NRCS) and the Bureau of Reclamation (Reclamation) from on- and off-farm improvements in the Uinta Basin totaled about 135,000 tons in 2013 (81,900 tons from on-farm improvements and 53,300 tons from off-farm improvements). The reduction in dissolved-solids load resulting from on- and off-farm improvements facilitated by the NRCS and Reclamation in the Price River Basin from 1989 to 2013 was estimated to be 64,800 tons.

The amount of sprinkler-irrigated land mapped in the drainage area or subbasin area for a gaging station was used to estimate the reduction in load resulting from the conversion from flood to sprinkler irrigation. Sprinkler-irrigated land mapped in the Uinta Basin totaled 109,630 acres in 2012. Assuming conversion to wheel-line sprinklers, a reduction in dissolved-solids load in the Uinta Basin of 95,800 tons in 2012 was calculated using the sprinkler-irrigation acreage and a pre-salinity-control project dissolved-solids yield of 1.04 tons per acre.

A reduction of 72,800 tons in dissolved-solids load from irrigation improvements was determined from sprinkler-irrigated lands in the Ashley Valley and Jensen, Pelican Lake, and Pleasant Valley areas (mapped in 2012); and in the Price River Basin (mapped in 2011). This decrease in dissolved-solids load is 8,800 tons more than the decrease in unmonitored flow-normalized dissolved-solids load (-64,000 tons) determined for the Green River between the Jensen and Green River gaging stations.

The net WY 1989–2013 change in flow-normalized dissolved-solids load at the Duchesne River near Randlett, UT, and the Green River between the Jensen and Green River, UT, gaging stations determined from mass-balance calculations was compared to reported reductions in dissolved-solids load from on- and off-farm improvements and estimated reductions in load determined from mapped sprinkler-irrigated areas in the Duchesne River Basin and the area draining to the Green River between the Jensen and Green River gaging stations. The combined NRCS and Reclamation estimates of reduction in dissolved-solids load from on- and off-farm improvements in the study area (200,000 tons) is more than the reduction in load estimated using the acreage with sprinkler improvements (136,000 tons) or the mass-balance of flow-normalized load (132,000 tons).

The Upper Mississippi River System—Topobathy

Released March 23, 2017 00:00 EST

2017, Fact Sheet 2016-3097

Jayme M. Stone, Jenny L. Hanson, Stephanie R. Sattler

The Upper Mississippi River System (UMRS), the navigable part of the Upper Mississippi and Illinois Rivers, is a diverse ecosystem that contains river channels, tributaries, shallow-water wetlands, backwater lakes, and flood-plain forests. Approximately 10,000 years of geologic and hydrographic history exist within the UMRS. Because it maintains crucial wildlife and fish habitats, the dynamic ecosystems of the Upper Mississippi River Basin and its tributaries are contingent on the adjacent flood plains and water-level fluctuations of the Mississippi River. Separate data for flood-plain elevation (lidar) and riverbed elevation (bathymetry) were collected on the UMRS by the U.S. Army Corps of Engineers’ (USACE) Upper Mississippi River Restoration (UMRR) Program. Using the two elevation datasets, the U.S. Geological Survey (USGS) Upper Midwest Environmental Sciences Center (UMESC) developed a systemic topobathy dataset.

Can we determine the biological availability of sediment-bound trace elements?

Released March 23, 2017 00:00 EST

1989, Hydrobiologia (176) 379-396

Samuel N. Luoma

It is clear from available data that the susceptibility of biological communities to trace element contamination differs among aquatic environments. One important reason is that the bioavailability of metals in sediments appears to be altered by variations in sediment geochemistry. However, methods for explaining or predicting the effect of sediment geochemistry upon metal bioavailability are poorly developed. Experimental studies demonstrate that ingestion of sediments and uptake from solution may both be important pathways of metal bioaccumulation in deposit/detritus feeding species. Relative importance between the two is geochemistry dependent. Geochemical characteristics of sediments also affect metal concentrations in the tissues of organisms collected from nature, but the specific mechanisms by which these characteristics influence metal bioavailability have not been rigorously demonstrated. Several prerequisites are necessary to better understand the processes that control metal bioavailability from sediments. 1) improved computational or analytical methods for analyzing distribution of metals among components of the sediments; 2) improved computational methods for assessing the influences of metal form in sediments on sediment-water metal exchange; and 3) a better understanding of the processes controlling bioaccumulation of metals from solution and food by metazoan species directly exposed to the sediments. Such capabilities would allow mechanistic explanations essential to the development of practical tools sought for determining sediment quality criteria for metals.

Ground water resources of southeastern Oakland County, Michigan

Released March 23, 2017 00:00 EST

1954, Report

J.G. Ferris, E.M. Burt, G.J. Stramel, E.G. Crosthwaite

The area covered by this report comprises a square which measures three townships on a side and enclose 318 square miles in southeastern Oakland County. The investigation of the ground-water resources of this area was made by the U.S. Geological Survey in cooperation with the Detroit Metropolitan Area Regional Planning Commission, the Michigan Department of Conservation, and the Michigan Water Resources Commission.

In 1950 the population of this nine-township area exceeded 341,000, or more than 86 percent of the total population of Oakland County. This county ranks third in the state in number of industrial establishments and workers and is fifteenth in agricultural importance. Its numerous lakes and rolling uplands contribute to its top rank in the state in the number of recreational enterprises in rural or suburban areas.

The climate is moderately humid. The average annual precipitation is 30 inches and the mean air temperature is 47.2° F. Snowfall averages 38 inches in the November-April interval. The growing season averages 151 days.

The regional land surface slopes from northwest to southeast and has a total relief of 360 feet. Pitted outwash plains and morainal hills that are more than 1,000 feet above sea level in the northwest corner of the area give way southeastward to a sequence of terminal moraines and intervening till plains in the middle part. These give way to the broad lake plains that cover the southeastern third of the area.

The area lies on the southeast edge of the Michigan Basin and the bedrock is composed of northwest dipping strata of the Devonian and Mississippian systems. The Antrim shale, of Lake Devonian and early Mississippian age, is the oldest formation cropping out beneath the mantle of glacial Berea sandstone, and Sunbury shale overlie the Antrim and are overlain by the Coldwater shale, their areas of outcrop beneath the drift lying successively farther northwest. These formations are of early Mississippian age.

Throughout the area the bedrock is covered by glacial drift which ranges in thickness from 25 to more than 350 feet. The drift increases in thickness from southeast to northwest, but considerable relief on the underlying bedrock surface greatly modifies this trend. Extensive moraines, till plains, lake plains, and gravel outwash plains cover the area. In the northwestern third of the area an extensive upland of gravel plains is dotted with lakes ranging from a few feet to more than 100 feet in depth.

Precipitation is the perennial source of all water in this area, whether on the surface of underground. The average annual rainfall on the nine-townships is equivalent to a continuous supply of 450 m.g.d. or  9 times the combined annual withdrawal from all wells in the area.

About 53 percent of the area is drained by the Clinton River, 44 percent by the River Rouge, and the remaining 3 percent by the Huron River. Less than one-third of the annual precipitation reappears as surface discharge from the watersheds of this area.

About two-thirds of the annual precipitation on the area is lost by evaporation from water and land surfaces and by transpirations from vegetative cover. A substantial part of this large annual water loss is from the many lakes and other exposed water surfaces and from contiguous lands where the depth to the water table is slight. Average annual water losses by evapotranspiration are equivalent to about 280 m.g.d. or nearly 6 times the combined withdrawal from all ground-water supplies in the area.

The principal aquifers are the alluvial deposits bordering streams and the buried outwash deposits which represent alluvial fills in preglacial or interglacial stream channels. Intensive well developments in the urban areas have greatly lowered ground-water levels in the buried outwash deposits, have brought localized problems of declining well yield, and have induced migration of mineralized waters from the underlying consolidated formations. During 1952, withdrawals of ground water in the nine township area averages about 50 m.g.d., most of this quantity being pumped from municipal wells. This annual pumpage was distributed as follows: 60 percent in Pontiac and environs; 20 percent in Birmingham, Royal Oak and Troy Township; and the remaining 20 percent throughout the suburban and rural areas.

Methods used to characterize the chemical composition and biological activity of environmental waters throughout the United States, 2012-14

Released March 22, 2017 14:45 EST

2017, Open-File Report 2017-1011

Kristin M. Romanok, Timothy J. Reilly, Larry B. Barber, J. Scott Boone, Herbert T. Buxton, William T. Foreman, Edward T. Furlong, Michelle Hladik, Luke R. Iwanowicz, Celeste Journey, Dana W. Kolpin, Kathryn Kuivila, Keith A. Loftin, Marc A. Mills, Michael T. Meyer, James L. Orlando, Kelly L. Smalling, Daniel L. Villeneuve, Paul M. Bradley

A vast array of chemical compounds are in wide commercial use in the United States, and the potential ecological and human-health effect of exposure to chemical mixtures has been identified as a high priority in environment health science. Awareness of the potential effects of low-level chemical exposures is rising. The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, conducted a study in which samples were collected from 38 streams in 25 States to provide an overview of contaminants found in stream water across the Nation. Additionally, biological screening assays were used to help determine any potential ecological and human-health effects of these chemical mixtures and to prioritize target chemicals for future toxicological studies. This report describes the site locations and the sampling and analytical methods and quality-assurance procedures used in the study.

Asynchrony in craniomandibular development and growth in Enhydra lutris nereis (Carnivora: Mustelidae): are southern sea otters born to bite?

Released March 22, 2017 00:00 EST

2017, Biological Journal of the Linnean Society

Chris J Law, Vikram B. Baliga, M. Tim Tinker, Rita S. Mehta

Weaning represents a major ontogenetic dietary shift in southern sea otters (Enhydra lutris nereis), as juveniles must transition from depending on mother’s milk to independently processing hard-shelled invertebrates. When the skulls of juveniles have reached sufficient maturity to transition to a durophagous diet remains to be investigated. Here, we conducted a comprehensive analysis of skull development and growth and sexual dimorphism using geometric morphometric approaches in 204 southern sea otter skulls. We found that southern sea otters of both sexes exhibit dramatic changes in cranial and mandibular shape and size over ontogeny. Although the majority of these changes occur in the pup stage, full development and growth of the skull does not occur until well after weaning. We hypothesize that the slower maturation of the crania of newly weaned juveniles serves as a handicap by constraining jaw adductor muscle size, biting ability and feeding on hard-shelled prey. In our analysis of sexual dimorphism, we found significant sexual shape and size dimorphism in adult craniomandibular morphology that arose through differences in developmental and growth rates and duration. We postulate that males are selected to attain mature crania faster to presumably reach adult biting ability sooner, gaining a competitive advantage in obtaining food and in male–male agonistic interactions.

Relationships between salinity and short-term soil carbon accumulation rates form marsh types across a landscape in the Mississippi River Delta

Released March 22, 2017 00:00 EST

2017, Wetlands

Melissa M. Baustian, Camille L. Stagg, Carey L Perry, Leland C Moss, Tim J.B. Carruthers, Mead Allison

Salinity alterations will likely change the plant and environmental characteristics in coastal marshes thereby influencing soil carbon accumulation rates. Coastal Louisiana marshes have been historically classified as fresh, intermediate, brackish, or saline based on resident plant community and position along a salinity gradient. Short-term total carbon accumulation rates were assessed by collecting 10-cm deep soil cores at 24 sites located in marshes spanning the salinity gradient. Bulk density, total carbon content, and the short-term accretion rates obtained with feldspar horizon markers were measured to determine total carbon accumulation rates. Despite some significant differences in soil properties among marsh types, the mean total carbon accumulation rates among marsh types were not significantly different (mean ± std. err. of 190 ± 27 g TC m−2 year−1). However, regression analysis indicated that mean annual surface salinity had a significant negative relationship with total carbon accumulation rates. Based on both analyses, the coastal Louisiana total marsh area (1,433,700 ha) accumulates about 2.7 to 3.3 Tg C year−1. Changing salinities due to increasing relative sea level or resulting from restoration activities may alter carbon accumulation rates in the short term and significantly influence the global carbon cycle.

The role of salinity tolerance and competition in the distribution of an endangered desert salt marsh endemic

Released March 22, 2017 00:00 EST

2017, Plant Ecology (218) 475-486

Lesley DeFalco, Sara Scoles, Emily R. Beamguard

Rare plants are often associated with distinctive soil types, and understanding why endemic species occur in unique environments is fundamental for their management. At Ash Meadows National Wildlife Refuge in southern Nevada, USA, we evaluated whether the limited distribution of endangered Amargosa niterwort (Nitrophila mohavensis) is explained by this species’ tolerance of saline soils on salt-encrusted mud flats compared with the broadly distributed desert saltgrass (Distichlis spicata var. stricta). We simultaneously explored whether niterwort distribution is restricted from expanding due to interspecific competition with saltgrass. Surface soils collected throughout niterwort’s range were unexpectedly less saline with lower extractable Na, seasonal electroconductivity, and Na absorption ratio, and higher soil moisture than in adjacent saltgrass or mixed shrub habitats. Comparison of niterwort and saltgrass growth along an experimental salinity gradient in a greenhouse demonstrated lower growth of niterwort at all but the highest NaCl concentrations. Although growth of niterwort ramets was similar when transplanted into both habitats at the refuge below Crystal Reservoir, niterwort reproductive effort was considerably higher in saltgrass compared to its own habitat, implying reallocation of resources to sexual reproduction to maximize fitness when the probability of ramet mortality increases with greater salinity stress. Saltgrass was not a demonstrated direct competitor of niterwort; however, this species is known to increase soil salinity by exuding salt ions and through litterfall. Niterwort conservation will benefit from protecting hydrological processes that reduce salinity stress and preventing saltgrass colonization into niterwort habitat.

Expert elicitation, uncertainty, and the value of information in controlling invasive species

Released March 22, 2017 00:00 EST

2017, Ecological Economics (137) 83-90

Fred A. Johnson, Brian J. Smith, Mathieu Bonneau, Julien Martin, Christina Romagosa, Frank J. Mazzotti, Hardin Waddle, Robert Reed, Jennifer Kettevrlin Eckles, Laurie J. Vitt

We illustrate the utility of expert elicitation, explicit recognition of uncertainty, and the value of information for directing management and research efforts for invasive species, using tegu lizards (Salvator merianae) in southern Florida as a case study. We posited a post-birth pulse, matrix model in which four age classes of tegus are recognized: hatchlings, 1 year-old, 2 year-olds, and 3 + year-olds. This matrix model was parameterized using a 3-point process to elicit estimates of tegu demographic rates in southern Florida from 10 herpetology experts. We fit statistical distributions for each parameter and for each expert, then drew and pooled a large number of replicate samples from these to form a distribution for each demographic parameter. Using these distributions, as well as the observed correlations among elicited values, we generated a large sample of matrix population models to infer how the tegu population would respond to control efforts. We used the concepts of Pareto efficiency and stochastic dominance to conclude that targeting older age classes at relatively high rates appears to have the best chance of minimizing tegu abundance and control costs. We conclude that expert opinion combined with an explicit consideration of uncertainty can be valuable in conducting an initial assessment of what control strategy, effort, and monetary resources are needed to reduce and eventually eliminate the invader. Scientists, in turn, can use the value of information to focus research in a way that not only increases the efficacy of control, but minimizes costs as well.

Distribution, nesting activities, and age-class of territorial pairs of golden eagles at the Altamont Pass Wind Resource Area, California, 2014–16

Released March 22, 2017 00:00 EST

2017, Open-File Report 2017-1035

Patrick S. Kolar, J. David Wiens

The substantial numbers of golden eagles (Aquila chrysaetos) killed by collisions with oldgeneration wind turbines each year at the Altamont Pass Wind Resource Area (APWRA) in California has been well documented from previous studies. Few eagle nests have been documented in the APWRA, however, and adults and subadults 3+ years of age killed by turbines were generally not associated with nearby territories. We searched a subset of randomly selected survey plots for territorial pairs of golden eagles and associated nesting attempts within the APWRA as part of a broader investigation of population dynamics in the surrounding northern Diablo Range. In contrast to limited historical observations from 1988 to 2013, our surveys documented up to 15 territorial pairs within 3.2 kilometers (km) of wind turbines at the APWRA annually, 9 of which were not previously documented or only observed intermittently during historical surveys. We found evidence of nesting activity by adult pairs at least once during our study at six of these territories. We also determined that 23–36 percent of territories identified within 3.2 km of the APWRA had a subadult pair member, but that no pairs with a subadult member attempted to nest. These data will be useful to developers, wildlife managers, and future raptor studies in the area to evaluate and minimize the potential effects of wind energy or other development activities on previously unknown territorial pairs in the area.

Age of the youngest volcanism at Eagle Lake, northeastern California—40Ar/39Ar and paleomagnetic results

Released March 22, 2017 00:00 EST

2017, Open-File Report 2017-1027

Michael A. Clynne, Andrew T. Calvert, Duane E. Champion, L.J.P. Muffler, Michael G. Sawlan, Drew T. Downs

The age of the youngest volcanism at Eagle Lake, California, was investigated using stratigraphic, paleomagnetic, and 40Ar/39Ar techniques. The three youngest volcanic lava flows at Eagle Lake yielded ages of 130.0±5.1, 127.5±3.2 and 123.6±18.7 ka, and are statistically indistinguishable. Paleomagnetic results demonstrate that two of the lava flows are very closely spaced in time, whereas the third is different by centuries to at most a few millennia. These results indicate that the basalt lava flows at Eagle Lake are not Holocene in age, and were erupted during an episode of volcanism at about 130–125 ka that is unlikely to have spanned more than a few thousand years. Thus, the short-term potential for subsequent volcanism at Eagle Lake is considered low. 

Geologic map of the Providence Mountains in parts of the Fountain Peak and adjacent 7.5' quadrangles, San Bernardino County, California

Released March 22, 2017 00:00 EST

2017, Scientific Investigations Map 3376

Paul Stone, David M. Miller, Calvin H. Stevens, Jose J. Rosario, Jorge A. Vazquez, Elmira Wan, Susan S. Priest, Zenon C. Valin


The Providence Mountains are in the eastern Mojave Desert about 60 km southeast of Baker, San Bernardino County, California. This range, which is noted for its prominent cliffs of Paleozoic limestone, is part of a northeast-trending belt of mountainous terrain more than 100 km long that also includes the Granite Mountains, Mid Hills, and New York Mountains. Providence Mountains State Recreation Area encompasses part of the range, the remainder of which is within Mojave National Preserve, a large parcel of land administered by the National Park Service. Access to the Providence Mountains is by secondary roads leading south and north from Interstate Highways 15 and 40, respectively, which bound the main part of Mojave National Preserve.

The geologic map presented here includes most of Providence Mountains State Recreation Area and land that surrounds it on the north, west, and south. This area covers most of the Fountain Peak 7.5′ quadrangle and small adjacent parts of the Hayden quadrangle to the north, the Columbia Mountain quadrangle to the northeast, and the Colton Well quadrangle to the east. The map area includes representative outcrops of most of the major geologic elements of the Providence Mountains, including gneissic Paleoproterozoic basement rocks, a thick overlying sequence of Neoproterozoic to Triassic sedimentary rocks, Jurassic rhyolite that intrudes and overlies the sedimentary rocks, Jurassic plutons and associated dikes, Miocene volcanic rocks, and a variety of Quaternary surficial deposits derived from local bedrock units. The purpose of the project was to map the area in detail, with primary emphasis on the pre-Quaternary units, to provide an improved stratigraphic, structural, and geochronologic framework for use in land management applications and scientific research.

Using multilevel models to quantify heterogeneity in resource selection

Released March 21, 2017 13:30 EST

2011, Journal of Wildlife Management (75) 1788-1796

Tyler Wagner, Duane R. Diefenbach, Sonja Christensen, Andrew S. Norton

Models of resource selection are being used increasingly to predict or model the effects of management actions rather than simply quantifying habitat selection. Multilevel, or hierarchical, models are an increasingly popular method to analyze animal resource selection because they impose a relatively weak stochastic constraint to model heterogeneity in habitat use and also account for unequal sample sizes among individuals. However, few studies have used multilevel models to model coefficients as a function of predictors that may influence habitat use at different scales or quantify differences in resource selection among groups. We used an example with white-tailed deer (Odocoileus virginianus) to illustrate how to model resource use as a function of distance to road that varies among deer by road density at the home range scale. We found that deer avoidance of roads decreased as road density increased. Also, we used multilevel models with sika deer (Cervus nippon) and white-tailed deer to examine whether resource selection differed between species. We failed to detect differences in resource use between these two species and showed how information-theoretic and graphical measures can be used to assess how resource use may have differed. Multilevel models can improve our understanding of how resource selection varies among individuals and provides an objective, quantifiable approach to assess differences or changes in resource selection.

Changes in community-level riparian plant traits over inundation gradients, Colorado River, Grand Canyon

Released March 21, 2017 00:00 EST

2017, Wetlands

Miles McCoy-Sulentic, Thomas Kolb, David Merritt, Emily C. Palmquist, Barbara Ralston, Daniel Sarr, Patrick B. Shafroth

Comparisons of community-level functional traits across environmental gradients have potential for identifying links among plant characteristics, adaptations to stress and disturbance, and community assembly. We investigated community-level variation in specific leaf area (SLA), plant mature height, seed mass, stem specific gravity (SSG), relative cover of C4 species, and total plant cover over hydrologic zones and gradients in years 2013 and 2014 in the riparian plant community along the Colorado River in the Grand Canyon. Vegetation cover was lowest in the frequently inundated active channel zone, indicating constraints on plant establishment and production by flood disturbance and anaerobic stress. Changes in trait values over hydrologic zones and inundation gradients indicate that frequently inundated plots exhibit a community-level ruderal strategy with adaptation to submergence (high SLA and low SSG, height, seed mass, C4 relative cover), whereas less frequently inundated plots exhibit adaptation to drought and infrequent flood disturbance (low SLA and high SSG, height, seed mass, C4 relative cover). Variation in traits not associated with inundation suggests niche differentiation and multiple modes of community assembly. The results enhance understanding of future responses of riparian communities of the Grand Canyon to anticipated drying and changes in hydrologic regime.

Acoustic telemetry and fisheries management

Released March 21, 2017 00:00 EST

2017, Ecological Applications

Glenn T. Crossin, Michelle R. Heupel, Christopher Holbrook, Nigel E. Hussey, Susan K Lowerre-Barbieri, Vivian M. Nguyen, Graham D. Raby, Steven J. Cooke

This paper reviews the use of acoustic telemetry as a tool for addressing issues in fisheries management, and serves as the lead to the special Feature Issue of Ecological Applications titled “Acoustic Telemetry and Fisheries Management”. Specifically, we provide an overview of the ways in which acoustic telemetry can be used to inform issues central to the ecology, conservation, and management of exploited and/or imperiled fish species. Despite great strides in this area in recent years, there are comparatively few examples where data have been applied directly to influence fisheries management and policy. We review the literature on this issue, identify the strengths and weaknesses of work done to date, and highlight knowledge gaps and difficulties in applying empirical fish telemetry studies to fisheries policy and practice. We then highlight the key areas of management and policy addressed, as well as the challenges that needed to be overcome to do this. We conclude with a set of recommendations about how researchers can, in consultation with stock assessment scientists and managers, formulate testable scientific questions to address and design future studies to generate data that can be used in a meaningful way by fisheries management and conservation practitioners. We also urge the involvement of relevant stakeholders (managers, fishers, conservation societies, etc.) early on in the process (i.e. in the co-creation of research projects), so that all priority questions and issues can be addressed effectively.

Harmonization of forest disturbance datasets of the conterminous USA from 1986 to 2011

Released March 21, 2017 00:00 EST

2017, Environmental Monitoring and Assessment (189)

Christopher E. Soulard, William Acevedo, Warren B. Cohen, Zhiqiang Yang, Stephen V. Stehman, Janis Taylor

Several spatial forest disturbance datasets exist for the conterminous USA. The major problem with forest disturbance mapping is that variability between map products leads to uncertainty regarding the actual rate of disturbance. In this article, harmonized maps were produced from multiple data sources (i.e., Global Forest Change, LANDFIRE Vegetation Disturbance, National Land Cover Database, Vegetation Change Tracker, and Web-Enabled Landsat Data). The harmonization process involved fitting common class ontologies and determining spatial congruency to produce forest disturbance maps for four time intervals (1986–1992, 1992–2001, 2001–2006, and 2006–2011). Pixels mapped as disturbed for two or more datasets were labeled as disturbed in the harmonized maps. The primary advantage gained by harmonization was improvement in commission error rates relative to the individual disturbance products. Disturbance omission errors were high for both harmonized and individual forest disturbance maps due to underlying limitations in mapping subtle disturbances with Landsat classification algorithms. To enhance the value of the harmonized disturbance products, we used fire perimeter maps to add information on the cause of disturbance.

A model to inform management actions as a response to chytridiomycosis-associated decline

Released March 21, 2017 00:00 EST

2017, EcoHealth (14) 144-155

Sarah Converse, Larissa L. Bailey, Brittany A. Mosher, W. Chris Funk, Brian D. Gerber, Erin L. Muths

Decision-analytic models provide forecasts of how systems of interest will respond to management. These models can be parameterized using empirical data, but sometimes require information elicited from experts. When evaluating the effects of disease in species translocation programs, expert judgment is likely to play a role because complete empirical information will rarely be available. We illustrate development of a decision-analytic model built to inform decision-making regarding translocations and other management actions for the boreal toad (Anaxyrus boreas boreas), a species with declines linked to chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd). Using the model, we explored the management implications of major uncertainties in this system, including whether there is a genetic basis for resistance to pathogenic infection by Bd, how translocation can best be implemented, and the effectiveness of efforts to reduce the spread of Bd. Our modeling exercise suggested that while selection for resistance to pathogenic infectionDecision-analytic models provide forecasts of how systems of interest will respond to management. These models can be parameterized using empirical data, but sometimes require information elicited from experts. When evaluating the effects of disease in species translocation programs, expert judgment is likely to play a role because complete empirical information will rarely be available. We illustrate development of a decision-analytic model built to inform decision-making regarding translocations and other management actions for the boreal toad (Anaxyrus boreas boreas), a species with declines linked to chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd). Using the model, we explored the management implications of major uncertainties in this system, including whether there is a genetic basis for resistance to pathogenic infection by Bd, how translocation can best be implemented, and the effectiveness of efforts to reduce the spread of Bd. Our modeling exercise suggested that while selection for resistance to pathogenic infection by Bd could increase numbers of sites occupied by toads, and translocations could increase the rate of toad recovery, efforts to reduce the spread of Bd may have little effect. We emphasize the need to continue developing and parameterizing models necessary to assess management actions for combating chytridiomycosis-associated declines. by Bd could increase numbers of sites occupied by toads, and translocations could increase the rate of toad recovery, efforts to reduce the spread of Bd may have little effect. We emphasize the need to continue developing and parameterizing models necessary to assess management actions for combating chytridiomycosis-associated declines.

Common Raven (Corvus corax) kleptoparasitism at a Golden Eagle (Aquila chyrsaetos) nest in southern Nevada

Released March 20, 2017 00:00 EST

2017, Wilson Journal of Ornithology (129) 195-198

Matthew Simes, Diego R. Johnson, Justin Streit, Kathleen Longshore, Kenneth E. Nussear, Todd C. Esque

The Common Raven (Corvus corax) is a ubiquitous species in the Mojave Desert of southern Nevada and California. From 5 to 24 May 2014, using remote trail cameras, we observed ravens repeatedly kleptoparasitizing food resources from the nest of a pair of Golden Eagles (Aquila chyrsaetos) in the Spring Mountains of southern Nevada. The ravens fed on nine (30%) of the 30 prey items delivered to the nest during the chick rearing period. Kleptoparasitic behavior by the ravens decreased as the eagle nestling matured to seven weeks of age, suggesting a narrow temporal window in which ravens can successfully engage in kleptoparasitic behavior at eagle nests. The observation of kleptoparasitism by Common Ravens at the nest suggests potential risks to young Golden Eagles from Common Ravens.

Pufferfish mortality associated with novel polar marine toxins in Hawaii

Released March 20, 2017 00:00 EST

2017, Diseases of Aquatic Organisms (123) 87-99

Thierry M. Work, Perer D. R. Moeller, Kevin R. Beauchesne, Julie Dagenais, Renee Breeden, Robert Rameyer, Willliam A. Walsh, Melanie Abecassis, Donald R. Kobayashi, Carla M. Conway, James Winton

Fish die-offs are important signals in tropical marine ecosystems. In 2010, a mass mortality of pufferfish in Hawaii (USA) was dominated by Arothron hispidus showing aberrant neurological behaviors. Using pathology, toxinology, and field surveys, we implicated a series of novel, polar, marine toxins as a likely cause of this mass mortality. Our findings are striking in that (1) a marine toxin was associated with a kill of a fish species that is itself toxic; (2) we provide a plausible mechanism to explain clinical signs of affected fish; and (3) this epizootic likely depleted puffer populations. Whilst our data are compelling, we did not synthesize the toxin de novo, and we were unable to categorically prove that the polar toxins caused mortality or that they were metabolites of an undefined parent compound. However, our approach does provide a template for marine fish kill investigations associated with marine toxins and inherent limitations of existing methods. Our study also highlights the need for more rapid and cost-effective tools to identify new marine toxins, particularly small, highly polar molecules.

Effects of internal phosphorus loadings and food-web structure on the recovery of a deep lake from eutrophication

Released March 20, 2017 00:00 EST

2017, Journal of Great Lakes Research (43) 255-264

Fabio Lepori, James J. Roberts

We used monitoring data from Lake Lugano (Switzerland and Italy) to assess key ecosystem responses to three decades of nutrient management (1983–2014). We investigated whether reductions in external phosphorus loadings (Lext) caused declines in lake phosphorus concentrations (P) and phytoplankton biomass (Chl a), as assumed by the predictive models that underpinned the management plan. Additionally, we examined the hypothesis that deep lakes respond quickly to Lext reductions. During the study period, nutrient management reduced Lext by approximately a half. However, the effects of such reduction on P and Chl a were complex. Far from the scenarios predicted by classic nutrient-management approaches, the responses of P and Chl a did not only reflect changes in Lext, but also variation in internal P loadings (Lint) and food-web structure. In turn, Lint varied depending on basin morphometry and climatic effects, whereas food-web structure varied due to apparently stochastic events of colonization and near-extinction of key species. Our results highlight the complexity of the trajectory of deep-lake ecosystems undergoing nutrient management. From an applied standpoint, they also suggest that [i] the recovery of warm monomictic lakes may be slower than expected due to the development of Lint, and that [ii] classic P and Chl a models based on Lext may be useful in nutrient management programs only if their predictions are used as starting points within adaptive frameworks.

Body mass, wing length, and condition of wintering ducks relative to hematozoa infection

Released March 20, 2017 00:00 EST

2017, Journal of Fish and Wildlife Management

Joseph Fleskes, Andrew M. Ramey, Andrew Reeves, Julie L. Yee

Waterfowl managers lack information regarding factors that may be reducing the positive response of waterfowl body condition to habitat improvements. Protozoan blood parasites (i.e., hematozoa) are commonly found in birds and have been related to reduced body mass, wing length, and body condition. We studied relationships between 12 measures of hematozoa infection and body mass, wing length, and body mass divided by wing length (i.e., body condition index [BCI]) of the five most common duck species (northern pintail [Anas acuta], mallard [A. platyrhynchos], green-winged teal [A. crecca], American wigeon [A. Americana], northern shoveler [A. clypeata]) wintering in the Central Valley of California during October 2006-January 2007. After accounting for variation due to species, age-sex cohort, Central Valley region, and month; wing length, body mass, and BCI were found to be negatively related to infection by Leucocytozoon and by "any hematozoa" but not related to infection by only Plasmodium or Haemoproteus, or coinfections of greater than one genera or parasite haplotype (albeit, few ducks had Plasmodium or Haemoproteus infection or coinfections). Evidence of a negative relationship with infection was stronger for body mass and BCI than for wing length and indicated that the relationships varied among species, age-sex cohorts, regions, and months. Compared to uninfected ducks, hematozoa-infected duck body mass, wing length, and BCI was -1.63% (85% CI = -2.79%- -0.47%), -0.12% (-0.41%- +0.17%), and -1.38% (-2.49%- -0.26%), respectively. Although, seemingly small, the -1.63% difference in body mass represents a large percentage (e.g., 38% for northern pintail) of the observed increase in wintering duck body mass associated with Central Valley habitat improvements. Because infection prevalence and relationship to body condition might change over time due to climate or other factors, tracking hematozoa infection prevalence might be important to inform and accurately assess the effect of conservation programs designed to improve waterfowl body condition.

Stable isotope analysis as an early monitoring tool for community-scale effects of rat eradication

Released March 17, 2017 00:00 EST

2017, Restoration Ecology

Katherine M. Nigro, Stacie A. Hathaway, Alex Wegmann, Ana Miller-ter Kuile, Robert N. Fisher, Hillary S. Young

Invasive rats have colonized most of the islands of the world, resulting in strong negative impacts on native biodiversity and on ecosystem functions. As prolific omnivores, invasive rats can cause local extirpation of a wide range of native species, with cascading consequences that can reshape communities and ecosystems. Eradication of rats on islands is now becoming a widespread approach to restore ecosystems, and many native island species show strong numerical responses to rat eradication. However, the effect of rat eradication on other consumers can extend beyond direct numerical effects, to changes in behavior, dietary composition, and other ecological parameters. These behavioral and trophic effects may have strong cascading impacts on the ecology of restored ecosystems, but they have rarely been examined. In this study, we explore how rat eradication has affected the trophic ecology of native land crab communities. Using stable isotope analysis of rats and crabs, we demonstrate that the diet or trophic position of most crabs changed subsequent to rat eradication. Combined with the numerical recovery of two carnivorous land crab species (Geograpsus spp.), this led to a dramatic widening of the crab trophic niche following rat eradication. Given the established importance of land crabs in structuring island communities, particularly plants, this suggests an unappreciated mechanism by which rat eradication may alter island ecology. This study also demonstrates the potential for stable isotope analysis as a complementary monitoring tool to traditional techniques, with the potential to provide more nuanced assessments of the community- and ecosystem-wide effects of restoration.

The vanishing cryovolcanoes of Ceres

Released March 17, 2017 00:00 EST

2017, Geophysical Research Letters (44) 1243-1250

Michael M. Sori, Shane Byrne, Michael Bland, Ali Bramson, Anton Ermakov, Christoper Hamilton, Katharina Otto, Ottaviano Ruesch, Christopher Russell

Ahuna Mons is a 4 km tall mountain on Ceres interpreted as a geologically young cryovolcanic dome. Other possible cryovolcanic features are more ambiguous, implying that cryovolcanism is only a recent phenomenon or that other cryovolcanic structures have been modified beyond easy identification. We test the hypothesis that Cerean cryovolcanic domes viscously relax, precluding ancient domes from recognition. We use numerical models to predict flow velocities of Ahuna Mons to be 10–500 m/Myr, depending upon assumptions about ice content, rheology, grain size, and thermal parameters. Slower flow rates in this range are sufficiently fast to induce extensive relaxation of cryovolcanic structures over 108–109 years, but gradual enough for Ahuna Mons to remain identifiable today. Positive topographic features, including a tholus underlying Ahuna Mons, may represent relaxed cryovolcanic structures. A composition for Ahuna Mons of >40% ice explains the observed distribution of cryovolcanic structures because viscous relaxation renders old cryovolcanoes unrecognizable.

Predicting the impacts of Mississippi River diversions and sea-level rise on spatial patterns of eastern oyster growth rate and production

Released March 17, 2017 00:00 EST

2017, Ecological Modelling (352) 40-53

Hongqing Wang, Qin Chen, Megan K. La Peyre, Kelin Hu, Jerome F. La Peyre

There remains much debate regarding the perceived tradeoffs of using freshwater and sediment diversions for coastal restoration in terms of balancing the need for wetland restoration versus preserving eastern oyster (Crassostrea virginica) production. Further complicating the issue, climate change-induced sea-level rise (SLR) and land subsidence are also expected to affect estuarine water quality. In this study, we developed a process-based numerical modeling system that couples hydrodynamic, water quality, and oyster population dynamics. We selected Breton Sound Estuary (BSE) (∼2740 km2) in the eastern Mississippi River Deltaic Plain since it is home to several of the largest public oyster seed grounds and private leases for the Gulf coast. The coupled oyster population model was calibrated and validated against field observed oyster growth data. We predicted the responses of oyster population in BSE to small- (142 m3 s−1) and large-scale (7080 m3 s−1) river diversions at the Caernarvon Freshwater Diversion structure planned in the 2012 Coastal Master Plan (Louisiana) under low (0.38 m) and high (1.44 m) relative sea-level rise (RSLR = eustatic SLR + subsidence) compared to a baseline condition (Year 2009). Model results showed that the large-scale diversion had a stronger negative impact on oyster population dynamics via freshening of the entire estuary, resulting in reduced oyster growth rate and production than RSLR. Under the large-scale diversion, areas with optimal oyster growth rates (>15 mg ash-free dry weight (AFDW) oyster−1 wk−1) and production (>500 g AFDW m−2 yr−1) would shift seaward to the southeastern edge of the estuary, turning the estuary into a very low oyster production system. RSLR however played a greater role than the small-scale diversion on the magnitude and spatial pattern of oyster growth rate and production. RSLR would result in an overall estuary-wide decrease in oyster growth rate and production as a consequence of decreased salinities in the middle and lower estuary because rising sea level likely causes increased stage and overbank flow downstream along the lower Mississippi River.

The U.S. Geological Survey Monthly Water Balance Model Futures Portal

Released March 16, 2017 11:00 EST

2017, Fact Sheet 2017-3002

Andy Bock

Simulations of future climate suggest profiles of temperature and precipitation may differ significantly from those in the past. These changes in climate will likely lead to changes in the hydrologic cycle. As such, natural resource managers are in need of tools that can provide estimates of key components of the hydrologic cycle, uncertainty associated with the estimates, and limitations associated with the climate forcing data used to estimate these components. To help address this need, the U.S. Geological Survey Monthly Water Balance Model Futures Portal ( provides a user friendly interface to deliver hydrologic and meteorological variables for monthly historic and potential future climatic conditions across the continental United States.

A critical evaluation of the utility of eggshells for estimating mercury concentrations in avian eggs

Released March 16, 2017 00:00 EST

2017, Environmental Toxicology and Chemistry

Sarah Peterson, Joshua T. Ackerman, Collin A. Eagles-Smith, C. Alex Hartman, Mark P. Herzog

Eggshells are a potential tool for non-lethally sampling contaminant concentrations in bird eggs, yet few studies have examined their utility to represent mercury exposure. We assessed mercury concentrations in eggshell components for 23 bird species and determined whether they correlated with total mercury (THg) in egg contents. We designed a multi-experiment analysis to examine how THg is partitioned into eggshell components, specifically hardened eggshells, material adhered to the eggshell, and inner eggshell membranes. THg concentrations in eggshells were much lower than in egg contents, and almost all of the THg within the eggshell was contained within material adhered to eggshells and inner eggshell membranes, and specifically not within calcium-rich hardened eggshells. Despite having very little mercury, THg concentrations in hardened eggshells had the strongest correlation with egg contents among all eggshell components. However, species with the same THg concentrations in eggshells had different THg concentrations in egg contents, indicating that there is no global predictive equation among species for the relationship between eggshell and egg content THg concentrations. Further, for all species, THg concentrations in eggshells decreased with relative embryo age. Although the majority of mercury in eggshells was contained within other eggshell components and not within hardened eggshells, THg in hardened eggshells can be used to estimate THg concentrations in egg contents, if embryo age and species are addressed.

Assessing the dietary bioavailability of metals associated with natural particles: Extending the use of the reverse labeling approach to zinc

Released March 16, 2017 00:00 EST

2017, Environmental Science and Technology (51) 2803-2810

Marie-Noele Croteau, Daniel J. Cain, Christopher C. Fuller

We extend the use of a novel tracing technique to quantify the bioavailability of zinc (Zn) associated with natural particles using snails enriched with a less common Zn stable isotope. Lymnaea stagnalis is a model species that has relatively fast Zn uptake rates from the dissolved phase, enabling their rapid enrichment in 67Zn during the initial phase of labeling. Isotopically enriched snails were subsequently exposed to algae mixed with increasing amounts of metal-rich particles collected from two acid mine drainage impacted rivers. Zinc bioavailability from the natural particles was inferred from calculations of 66Zn assimilation into the snail’s soft tissues. Zinc assimilation efficiency (AE) varied from 28% for the Animas River particles to 45% for the Snake River particles, indicating that particle-bound, or sorbed Zn, was bioavailable from acid mine drainage wastes. The relative binding strength of Zn sorption to the natural particles was inversely related to Zn bioavailability; a finding that would not have been possible without using the reverse labeling approach. Differences in the chemical composition of the particles suggest that their geochemical properties may influence the extent of Zn bioavailability.

Influence of atmospheric rivers on vegetation productivity and fire patterns in the southwestern U.S.

Released March 16, 2017 00:00 EST

2017, Journal of Geophysical Research: Biogeosciences (122) 308-323

Christine M. Albano, Michael Dettinger, Christopher E. Soulard

In the southwestern U.S., the meteorological phenomenon known as atmospheric rivers (ARs) has gained increasing attention due to its strong connections to floods, snowpacks, and water supplies in the West Coast states. Relatively less is known about the ecological implications of ARs, particularly in the interior Southwest, where AR storms are less common. To address this gap, we compared a chronology of AR landfalls on the west coast between 1989 and 2011 and between 25°N and 42.5°N to annual metrics of the normalized difference vegetation index (NDVI; an indicator of vegetation productivity) and daily resolution precipitation data to assess influences of AR-fed winter precipitation on vegetation productivity across the southwestern U.S. We mapped correlations between winter AR precipitation during landfalling ARs and (1) annual maximum NDVI and (2) area burned by large wildfires summarized by ecoregion during the same year as the landfalls and during the following year. Interannual variations of AR precipitation strongly influenced both NDVI and area burned by wildfire in some dryland ecoregions. The influence of ARs on dryland vegetation varied significantly depending on the latitude of landfall, with those ARs making landfall below 35°N latitude more strongly influencing these systems, and with effects observed as far as 1300 km from the landfall location. As climatologists' understanding of the synoptic patterns associated with the occurrence of ARs continues to evolve, an increased understanding of how AR landfalls, in aggregate, influence vegetation productivity and associated wildfire activity in dryland ecosystems may provide opportunities to better predict ecological responses to climate and climate change.

Vertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA)

Released March 16, 2017 00:00 EST

2017, Geology of the Intermountain West (4) 55-98

Kathleen Springer, Jeffery S. Pigati, Eric Scott

Tule Springs Fossil Beds National Monument (TUSK) preserves 22,650 acres of the upper Las Vegas Wash in the northern Las Vegas Valley (Nevada, USA). TUSK is home to extensive and stratigraphically complex groundwater discharge (GWD) deposits, called the Las Vegas Formation, which represent springs and desert wetlands that covered much of the valley during the late Quaternary. The GWD deposits record hydrologic changes that occurred here in a dynamic and temporally congruent response to abrupt climatic oscillations over the last ~300 ka (thousands of years). The deposits also entomb the Tule Springs Local Fauna (TSLF), one of the most significant late Pleistocene (Rancholabrean) vertebrate assemblages in the American Southwest. The TSLF is both prolific and diverse, and includes a large mammal assemblage dominated by Mammuthus columbi and Camelops hesternus. Two (and possibly three) distinct species of Equus, two species of Bison, Panthera atrox, Smilodon fatalis, Canis dirus, Megalonyx jeffersonii, and Nothrotheriops shastensis are also present, and newly recognized faunal components include micromammals, amphibians, snakes, and birds. Invertebrates, plant macrofossils, and pollen also occur in the deposits and provide important and complementary paleoenvironmental information. This field compendium highlights the faunal assemblage in the classic stratigraphic sequences of the Las Vegas Formation within TUSK, emphasizes the significant hydrologic changes that occurred in the area during the recent geologic past, and examines the subsequent and repeated effect of rapid climate change on the local desert wetland ecosystem.

The effect of wet-dry weathering on the rate of bedrock river channel erosion by saltating gravel

Released March 15, 2017 00:00 EST

2017, Geomorphology (285) 152-161

Takuya Inoue, Satomi Yamaguchi, Jonathan M. Nelson

Previous work has shown that the bedrock erosion rate E because of collisions of saltating bedload can be expressed by E = βqb(1-Pc), where qb is the sediment transport rate, Pc is the extent of alluvial cover, and β is the abrasion coefficient. However, the dependence of the abrasion coefficient on the physical characteristics of the bedrock material is poorly known, and in particular, the effects of wet-dry weathering on the saltation-abrasion bedrock incision has not been specifically characterized. Observation suggests that the typical wet-dry cycling of exposed bedrock in river beds gives rise to cracks and voids that are likely to alter the incision rate of the material when subjected to impacts of moving sediment. In this study, flume experiments are performed to develop an understanding of how wet-dry cycling affects the rock tensile strength and the bedrock erosion rate. To represent the physical effects of weathering, boring cores taken from natural bedrock channel are exposed to artificial wet-dry cycles. The experimental results suggest the following: (1) the abrasion coefficient for fresh bedrock is estimated by β = 1.0 × 10− 4σT− 2(d/ksb)0.5, where σT is the tensile strength, d is the diameter of colliding gravel, and ksb is the hydraulic roughness height of bedrock; (2) the tensile strength of the bedrock decreases exponentially as a result of repeated wet-dry cycles, σTT0 = exp (-CTNWa0T0), where σT0 is the initial tensile strength, Wa0 is the initial normalized rate of water absorption., N is the number of wet-dry cycles, and CT is a constant; (3) the erosion rate of fresh bedrock depends on the inverse of the square of tensile strength, but the erosion rate of weathered bedrock depends on the − 1.5 power of tensile strength.

Assessing the influence of sustainable trail design and maintenance on soil loss

Released March 15, 2017 00:00 EST

2017, Journal of Environmental Management (189) 46-57

Jeff Marion, Jeremy Wimpey

Natural-surfaced trail systems are an important infrastructure component providing a means for accessing remote protected natural area destinations. The condition and usability of trails is a critical concern of land managers charged with providing recreational access while preserving natural conditions, and to visitors seeking high quality recreational opportunities and experiences. While an adequate number of trail management publications provide prescriptive guidance for designing, constructing, and maintaining natural-surfaced trails, surprisingly little research has been directed at providing a scientific basis for this guidance. Results from a review of the literature and three scientific studies are presented to model and clarify the influence of factors that substantially influence trail soil loss and that can be manipulated by trail professionals to sustain high traffic while minimizing soil loss over time. Key factors include trail grade, slope alignment angle, tread drainage features, and the amount of rock in tread substrates. A new Trail Sustainability Rating is developed and offered as a tool for evaluating or improving the sustainability of existing or new trails.

Public-supply water use in Kansas, 2015

Released March 15, 2017 00:00 EST

2017, Dataset

Jennifer Lanning-Rush, Diana Restrepo-Osorio

This U.S. Geological Survey (USGS) Data Release provides derivative statistics of water used by Kansas public-supply systems in 2015. Gallons per capita per day is calculated using self-reported information in the “Part B: Monthly Water Use Summary” and “Part C: Population, Service Connections, and Water Rates” sections of the Kansas Department of Agriculture, Division of Water Resources' (DWR) annual municipal water use report (see appendixes at for an example of a municipal water use report form.) Percent unaccounted for water is calculated using self-reported information in “Part B: Monthly Water Use Summary” of the DWR’s municipal water-use report. The published statistics from the previous 4 years (2011–2014) are also shown with the 2015 statistics and are used to calculate a 5-year average. Derivative statistics of 2011, 2012, 2013, 2014, 2015, and 5-year averages for gallons per capita per day (gpcd) are also provided by the Kansas Water Authority's 14 regional planning areas, and the DWR regions used for analysis of per capita water use in Kansas. An overall Kansas average (yearly and 5-year average) is also calculated. Kansas state average per capita municipal water use in 2015 was 105 gpcd.

Operational shoreline mapping with high spatial resolution radar and geographic processing

Released March 15, 2017 00:00 EST

2017, Photogrammetric Engineering and Remote Sensing (83) 237-246

Amina Rangoonwala, Cathleen E Jones, Zhaohui Chi, Elijah W. Ramsey III

A comprehensive mapping technology was developed utilizing standard image processing and available GIS procedures to automate shoreline identification and mapping from 2 m synthetic aperture radar (SAR) HH amplitude data. The development used four NASA Uninhabited Aerial Vehicle SAR (UAVSAR) data collections between summer 2009 and 2012 and a fall 2012 collection of wetlands dominantly fronted by vegetated shorelines along the Mississippi River Delta that are beset by severe storms, toxic releases, and relative sea-level rise. In comparison to shorelines interpreted from 0.3 m and 1 m orthophotography, the automated GIS 10 m alongshore sampling found SAR shoreline mapping accuracy to be ±2 m, well within the lower range of reported shoreline mapping accuracies. The high comparability was obtained even though water levels differed between the SAR and photography image pairs and included all shorelines regardless of complexity. The SAR mapping technology is highly repeatable and extendable to other SAR instruments with similar operational functionality.

Functional traits and ecological affinities of riparian plants along the Colorado River in Grand Canyon

Released March 15, 2017 00:00 EST

2017, Western North American Naturalist (77)

Emily C. Palmquist, Barbara Ralston, Sarr. Daniel, David Merritt, Patrick B Shafroth, Julian Scott

Trait-based approaches to vegetation analyses are becoming more prevalent in studies of riparian vegetation dynamics, including responses to flow regulation, groundwater pumping, and climate change. These analyses require species trait data compiled from the literature and floras or original field measurements. Gathering such data makes trait-based research time intensive at best and impracticable in some cases. To support trait-based analysis of vegetation along the Colorado River through Grand Canyon, a data set of 20 biological traits and ecological affinities for 179 species occurring in that study area was compiled. This diverse flora shares species with many riparian areas in the western USA and includes species that occur across a wide moisture gradient. Data were compiled from published scientific papers, unpublished reports, plant fact sheets, existing trait databases, regional floras, and plant guides. Data for ordinal environmental tolerances were more readily available than were quantitative traits. More publicly available data are needed for traits of both common and rare southwestern U.S. plant species to facilitate comprehensive, trait-based research. The trait data set is free to use and can be downloaded from ScienceBase: and

Toxicity of chromium (VI) to two mussels and an amphipod in water-only exposures with or without a co-stressor of elevated temperature, zinc, or nitrate

Released March 15, 2017 00:00 EST

2017, Archives of Environmental Contamination and Toxicology (72) 449-460

Ning Wang, James L. Kunz, Chris D. Ivey, Christopher G. Ingersoll, M. Christopher Barnhart, Elizabeth A. Glidewell

The objectives of the present study were to develop methods for propagating western pearlshell (Margaritifera falcata) for laboratory toxicity testing and evaluate acute and chronic toxicity of chromium VI [Cr(VI)] to the pearlshell and a commonly tested mussel (fatmucket, Lampsilis siliquoidea at 20 °C or in association with a co-stressor of elevated temperature (27 °C), zinc (50 µg Zn/L), or nitrate (35 mg NO3/L). A commonly tested invertebrate (amphipod, Hyalella azteca) also was tested in chronic exposures. Newly transformed pearlshell (~1 week old) were successfully cultured and tested in acute 96 h Cr exposures (control survival 100%). However, the grow-out of juveniles in culture for chronic toxicity testing was less successful and chronic 28-day Cr toxicity tests started with 4 month-old pearlshell failed due to low control survival (39–68%). Acute median effect concentration (EC50) for the pearlshell (919 µg Cr/L) and fatmucket (456 µg Cr/L) tested at 20 °C without a co-stressor decreased by a factor of > 2 at elevated temperature but did not decrease at elevated Zn or elevated NO3. Chronic 28-day Cr tests were completed successfully with the fatmucket and amphipod (control survival 83–98%). Chronic maximum acceptable toxicant concentration (MATC) for fatmucket at 20 °C (26 µg Cr/L) decreased by a factor of 2 at elevated temperature or NO3 but did not decrease at elevated Zn. However, chronic MATC for amphipod at 20 °C (13 µg Cr/L) did not decrease at elevated temperature, Zn, or NO3. Acute EC50s for both mussels tested with or without a co-stressor were above the final acute value used to derive United States Environmental Protection Agency acute water quality criterion (WQC) for Cr(VI); however, chronic MATCs for fatmucket at elevated temperature or NO3 and chronic MATCs for the amphipod at 20 °C with or without elevated Zn or NO3 were about equal to the chronic WQC. The results indicate that (1) the elevated temperature increased the acute Cr toxicity to both mussel species, (2) fatmucket was acutely more sensitive to Cr than the pearlshell, (3) elevated temperature or NO3 increased chronic Cr toxicity to fatmucket, and (4) acute WQC are protective of tested mussels with or without a co-stressor; however, the chronic WQC might not protect fatmucket at elevated temperature or NO3 and might not protect the amphipod at 20 °C with or without elevated Zn or NO3.

Understanding ecosystem services adoption by natural resource managers and research ecologists

Released March 15, 2017 00:00 EST

2017, Journal of Great Lakes Research

Daniel Engel, Mary Anne Evans, Bobbi S. Low, Jeff Schaeffer

The ecosystem services (ES) paradigm has gained much traction as a natural resource management approach due to its comprehensive nature and ability to provide quantitative tools to improve decision-making. However, it is still uncertain whether and how practitioners have adopted the ES paradigm into their work and how this aligns with resource management information needs. To address this, we surveyed natural resource managers within the Great Lakes region about their use of ES information in decision-making. We complemented our manager survey with in-depth interviews of a related population—research ecologists at the U.S. Geological Survey Great Lakes Science Center. In this study, managers and ecologists almost unanimously agreed that ES were appropriate to consider in resource management. We also found high congruence between managers and ecologists in the ES considered most relevant to their work, with provision of habitat, recreation and tourism, biological control, and primary production being the ES ranked highly by both groups. However, a disconnect arose when research ecologists deemed the information they provide regarding ES as adequate for management needs, but managers disagreed. Furthermore, managers reported that they would use economic information about ES if they had access to that information. We believe this data deficiency could represent a gap in scientific coverage by ecologists, but it may also simply reflect an underrepresentation of ecological economists who can translate ecological knowledge of ES providers into economic information that many managers desired.

Effects of food web changes on Mysis diluviana diet in Lake Ontario

Released March 15, 2017 00:00 EST

2017, Journal of Great Lakes Research

Brian P. O'Malley, Lars G. Rudstam, James M. Watkins, Toby J. Holda, Brian C. Weidel

Mysids are important benthic-pelagic omnivores in many deep-lake food webs, yet quantitative data on their diet are limited. We explored the trophic role of Mysis diluviana in offshore Lake Ontario using samples collected in May, July, and September 2013 with a focus on seasonal and ontogenetic patterns in herbivory and zooplanktivory using two approaches. We hypothesized that Mysis diet in 2013 differs from the last investigation in 1995 in response to changes in pelagic prey over 1995 to 2013. Gut fluorescence indicated high grazing by adult and juvenile Mysis in May 2013. In July, smaller mysids were more herbivorous than larger individuals, a pattern that was less pronounced in September. Microscopic gut analysis showed copepods, including Limnocalanus, were common in diets of both size groups in May. In July, mainly cladocerans were consumed, including Cercopagis pengoi which represents a change from a past investigation that preceded Cercopagis invasion in the lake. Our results are consistent with earlier observations of a larger proportion of algae in mysid diets in spring, transitioning to relatively more zooplanktivory and use of cladocerans in the summer and fall. Higher chlorophyll content in small mysids in July than in September may be associated with the presence of a deep chlorophyll layer in July that had largely dissipated by September. Overall, Mysis in Lake Ontario continues to be a generalist omnivore, incorporating new prey items and exhibiting higher herbivory in spring.

The significant surface-water connectivity of "geographically isolated wetlands"

Released March 15, 2017 00:00 EST

2017, Wetlands

Aram J. K. Calhoun, David M. Mushet, Laurie C. Alexander, Edward S. DeKeyser, Laurie Fowler, Charles R. Lane, Megan W. Lang, Mark C. Rains, Stephen Richter, Susan Walls

We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be “geographically isolated” (sensu Tiner Wetlands 23:494–516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be “geographically isolated” shows the difficulties in grouping an ecological resource that does not reliably indicate lack of surface water connectivity in order to meet legal, regulatory, or scientific needs. Additionally, the practice of identifying “geographically isolated wetlands” based on distance from a stream can result in gross overestimates of the number of wetlands lacking ecologically important surface-water connections. Our findings do not support use of the overly simplistic label of “geographically isolated wetlands”. Wetlands surrounded by uplands vary in function and surface-water connections based on wetland landscape setting, context, climate, and geographic region and should be evaluated as such. We found that the “geographically isolated” grouping does not reflect our understanding of the hydrologic variability of these wetlands and hence does not benefit conservation of the Nation’s diverse wetland resources. Therefore, we strongly discourage use of categorizations that provide overly simplistic views of surface-water connectivity of wetlands fully embedded in upland landscapes.

Identifying small depressional wetlands and using a topographic position index to infer hydroperiod regimes for pond-breeding amphibians

Released March 15, 2017 00:00 EST

2017, Wetlands

Jeffrey W. Riley, Daniel L. Calhoun, William J. Barichivich, Susan C. Walls

Small, seasonal pools and temporary ponds (<4.0 ha) are the most numerous and biologically diverse wetlands in many natural landscapes. Thus, accurate determination of their numbers and spatial characteristics is beneficial for conservation and management of biodiversity associated with these freshwater systems. We examined the utility of a topographic position index (TPI) landscape classification to identify and classify depressional wetlands. We also assessed relationships between topographic characteristics and ponded duration of known wetlands to allow hydrological characteristics to be extended to non-monitored locations in similar landscapes. Our results indicate that this approach was successful at identifying wetlands, but did have higher errors of commission (10%) than omission (5%). Additionally, the TPI procedure provided a reasonable means to correlate general ponded duration characteristics (long/short) with wetland topography. Although results varied by hydrologic class, permanent/long ponded duration wetlands were more often classified correctly (80%) than were short ponded duration wetlands (67%). However, classification results were improved to 100 and 75% for permanent/long and short ponded duration wetlands, respectively, by removing wetlands occurring on an abrupt marine terrace that erroneously inflated pond topographic characteristics. Our study presents an approach for evaluating wetland suitability for species or guilds that are associated with key habitat characteristics, such as hydroperiod.

Citizen science can improve conservation science, natural resource management, and environmental protection

Released March 15, 2017 00:00 EST

2017, Biological Conservation

Duncan C. McKinley, Abe J. Miller-Rushing, Heidi L. Ballard, Rick Bonney, Hutch Brown, Susan Cook-Patton, Daniel M. Evans, Rebecca A. French, Julia Parrish, Tina B. Phillips, Sean F. Ryan, Lea A. Shanley, Jennifer L. Shirk, Kristine F. Stepenuck, Jake Weltzin, Andrea Wiggins, Owen D. Boyle, Russell D. Briggs, Stuart F. Chapin III, David A. Hewitt, Peter W. Preuss, Michael A. Soukup

Citizen science has advanced science for hundreds of years, contributed to many peer-reviewed articles, and informed land management decisions and policies across the United States. Over the last 10 years, citizen science has grown immensely in the United States and many other countries. Here, we show how citizen science is a powerful tool for tackling many of the challenges faced in the field of conservation biology. We describe the two interwoven paths by which citizen science can improve conservation efforts, natural resource management, and environmental protection. The first path includes building scientific knowledge, while the other path involves informing policy and encouraging public action. We explore how citizen science is currently used and describe the investments needed to create a citizen science program. We find that:

  1. Citizen science already contributes substantially to many domains of science, including conservation, natural resource, and environmental science. Citizen science informs natural resource management, environmental protection, and policymaking and fosters public input and engagement.
  2. Many types of projects can benefit from citizen science, but one must be careful to match the needs for science and public involvement with the right type of citizen science project and the right method of public participation.
  3. Citizen science is a rigorous process of scientific discovery, indistinguishable from conventional science apart from the participation of volunteers. When properly designed, carried out, and evaluated, citizen science can provide sound science, efficiently generate high-quality data, and help solve problems.

Status and trends of dam removal research in the United States

Released March 15, 2017 00:00 EST

2017, WIREs Water (4)

James Bellmore, Jeff Duda, Laura Craig, Samantha L. Greene, Christian Torgersen, Mathias J. Collins, Katherine Vittum

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies will increasingly be called upon to inform decisions about whether, and how best, to bring down dams. This raises a critical question: what is the current state of dam-removal science in the United States? To explore the status, trends, and characteristics of dam-removal research in the U.S., we searched the scientific literature and extracted basic information from studies on dam removal. Our literature review illustrates that although over 1200 dams have been removed in the U.S., fewer than 10% have been scientifically evaluated, and most of these studies were short in duration ( < 4 years) and had limited (1–2 years) or no pre-removal monitoring. The majority of studies focused on hydrologic and geomorphic responses to removal rather than biological and water-quality responses, and few studies were published on linkages between physical and ecological components. Our review illustrates the need for long-term, multidisciplinary case studies, with robust study designs, in order to anticipate the effects of dam removal and inform future decision making.

Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake

Released March 14, 2017 00:00 EST

2017, International Journal for Parasitology

Miroslava Soldánová, Simona Georgieva, Jana Roháčováa, Rune Knudsen, Jesper A. Kuhn, Eirik H. Henriksen, Anna Siwertsson, Jenny C. Shaw, Armand M. Kuris, Per-Arne Amundsen, Tomáš Scholz, Kevin D. Lafferty, Aneta Kostadinova

To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages), and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem, and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages.

Similarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season

Released March 14, 2017 00:00 EST

2017, Science of the Total Environment (579) 149-158

Barbara J. Mahler, Peter VanMetre, Thomas E. Burley, Keith A. Loftin, Michael T. Meyer, Lisa H. Nowell

Glyphosate and atrazine are the most intensively used herbicides in the United States. Although there is abundant spatial and temporal information on atrazine occurrence at regional scales, there are far fewer data for glyphosate, and studies that compare the two herbicides are rare. We investigated temporal patterns in glyphosate and atrazine concentrations measured weekly during the 2013 growing season in 100 small streams in the Midwestern United States. Glyphosate was detected in 44% of samples (method reporting level 0.2 μg/L); atrazine was detected above a threshold of 0.2 μg/L in 54% of samples. Glyphosate was detected more frequently in 12 urban streams than in 88 agricultural streams, and at concentrations similar to those in streams with high agricultural land use (> 40% row crop) in the watershed. In contrast, atrazine was detected more frequently and at higher concentrations in agricultural streams than in urban streams. The maximum concentration of glyphosate measured at most urban sites exceeded the maximum atrazine concentration, whereas at agricultural sites the reverse was true. Measurement at a 2-day interval at 8 sites in northern Missouri revealed that transport of both herbicide compounds appeared to be controlled by spring flush, that peak concentration duration was brief, but that peaks in atrazine concentrations were of longer duration than those of glyphosate. The 2-day sampling also indicated that weekly sampling is unlikely to capture peak concentrations of glyphosate and atrazine.

Voice, perceived fairness, agency trust, and acceptance of management decisions among Minnesota anglers

Released March 14, 2017 00:00 EST

2017, Society and Natural Resources

Susan A. Schroeder, David C. Fulton

Although researchers agree that public participation in natural resource decision making is critical to institutional acceptance by stakeholders and the general public, the processes to gain public perceptions of fairness, agency trust, and acceptance of management decisions are not clear. Using results from a mail survey of Minnesota resident anglers, we used structural equation modeling to examine how instrumental versus symbolic motives related to anglers’ perceptions of agency fairness, trustworthiness, and ultimately acceptance of fisheries management decisions. We applied laboratory research on relationships among procedural fairness, trust, and management acceptance, and then tested models incorporating anglers’ perceptions of voice for anglers and nonanglers in management decisions. Results suggested that trust fully mediated the relationship between procedural fairness and management acceptance. Angler perceptions of angler and nonangler voice both related to views of procedural fairness, but angler voice was more strongly related and was also significantly related to acceptance of management decisions.

Risk, liability, and economic issues with long-term CO2 storage—A review

Released March 14, 2017 00:00 EST

2017, Natural Resources Research (26) 89-112

Steven T. Anderson

Given a scarcity of commercial-scale carbon capture and storage (CCS) projects, there is a great deal of uncertainty in the risks, liability, and their cost implications for geologic storage of carbon dioxide (CO2). The probabilities of leakage and the risk of induced seismicity could be remote, but the volume of geologic CO2 storage (GCS) projected to be necessary to have a significant impact on increasing CO2 concentrations in the atmosphere is far greater than the volumes of CO2 injected thus far. National-level estimates of the technically accessible CO2storage resource (TASR) onshore in the United States are on the order of thousands of gigatons of CO2 storage capacity, but such estimates generally assume away any pressure management issues. Pressure buildup in the storage reservoir is expected to be a primary source of risk associated with CO2 storage, and only a fraction of the theoretical TASR could be available unless the storage operator extracts the saltwater brines or other formation fluids that are already present in the geologic pore space targeted for CO2 storage. Institutions, legislation, and processes to manage the risk, liability, and economic issues with CO2 storage in the United States are beginning to emerge, but will need to progress further in order to allow a commercial-scale CO2 storage industry to develop in the country. The combination of economic tradeoffs, property rights definitions, liability issues, and risk considerations suggests that CO2 storage offshore of the United States may be more feasible than onshore, especially during the current (early) stages of industry development.

Cost implications of uncertainty in CO2 storage resource estimates: A review

Released March 14, 2017 00:00 EST

2017, Natural Resources Research (26) 137-159

Steven T. Anderson

Carbon capture from stationary sources and geologic storage of carbon dioxide (CO2) is an important option to include in strategies to mitigate greenhouse gas emissions. However, the potential costs of commercial-scale CO2 storage are not well constrained, stemming from the inherent uncertainty in storage resource estimates coupled with a lack of detailed estimates of the infrastructure needed to access those resources. Storage resource estimates are highly dependent on storage efficiency values or storage coefficients, which are calculated based on ranges of uncertain geological and physical reservoir parameters. If dynamic factors (such as variability in storage efficiencies, pressure interference, and acceptable injection rates over time), reservoir pressure limitations, boundaries on migration of CO2, consideration of closed or semi-closed saline reservoir systems, and other possible constraints on the technically accessible CO2 storage resource (TASR) are accounted for, it is likely that only a fraction of the TASR could be available without incurring significant additional costs. Although storage resource estimates typically assume that any issues with pressure buildup due to CO2 injection will be mitigated by reservoir pressure management, estimates of the costs of CO2 storage generally do not include the costs of active pressure management. Production of saline waters (brines) could be essential to increasing the dynamic storage capacity of most reservoirs, but including the costs of this critical method of reservoir pressure management could increase current estimates of the costs of CO2 storage by two times, or more. Even without considering the implications for reservoir pressure management, geologic uncertainty can significantly impact CO2 storage capacities and costs, and contribute to uncertainty in carbon capture and storage (CCS) systems. Given the current state of available information and the scarcity of (data from) long-term commercial-scale CO2 storage projects, decision makers may experience considerable difficulty in ascertaining the realistic potential, the likely costs, and the most beneficial pattern of deployment of CCS as an option to reduce CO2 concentrations in the atmosphere.

A science of integration: frameworks, processes, and products in a place-based, integrative study

Released March 14, 2017 00:00 EST

2017, Sustainability Science (12) 293-303

Andrew Kliskey, Lilian Alessa, Sarah Wandersee, Paula Williams, Jamie Trammell, Jim Powell, Jess Grunblatt, Mark S. Wipfli

ntegrative research is increasingly a priority within the scientific community and is a central goal for the evolving field of sustainability science. While it is conceptually attractive, its successful implementation has been challenging and recent work suggests that the move towards interdisciplinarity and transdisciplinarity in sustainability science is being only partially realized. To address this from the perspective of social-ecological systems (SES) research, we examine the process of conducting a science of integration within the Southcentral Alaska Test Case (SCTC) of Alaska-EPSCoR as a test-bed for this approach. The SCTC is part of a large, 5 year, interdisciplinary study investigating changing environments and adaptations to those changes in Alaska. In this paper, we review progress toward a science of integration and present our efforts to confront the practical issues of applying proposed integration frameworks. We: (1) define our integration framework; (2) describe the collaborative processes, including the co-development of science through stakeholder engagement and partnerships; and (3) illustrate potential products of integrative, social-ecological systems research. The approaches we use can also be applied outside of this particular framework. We highlight challenges and propose improvements for integration in sustainability science by addressing the need for common frameworks and improved contextual understanding. These insights may be useful for capacity-building for interdisciplinary projects that address complex real-world social and environmental problems.

Using maximum entropy to predict suitable habitat for the endangered dwarf wedgemussel in the Maryland Coastal Plain

Released March 14, 2017 00:00 EST

2017, Aquatic Conservation: Marine and Freshwater Ecosystems

Cara Campbell, Robert H. Hilderbrand

  1. Species distribution modelling can be useful for the conservation of rare and endangered species. Freshwater mussel declines have thinned species ranges producing spatially fragmented distributions across large areas. Spatial fragmentation in combination with a complex life history and heterogeneous environment makes predictive modelling difficult.
  2. A machine learning approach (maximum entropy) was used to model occurrences and suitable habitat for the federally endangered dwarf wedgemussel, Alasmidonta heterodon, in Maryland's Coastal Plain catchments. Landscape-scale predictors (e.g. land cover, land use, soil characteristics, geology, flow characteristics, and climate) were used to predict the suitability of individual stream segments for A. heterodon.
  3. The best model contained variables at three scales: minimum elevation (segment scale), percentage Tertiary deposits, low intensity development, and woody wetlands (sub-catchment), and percentage low intensity development, pasture/hay agriculture, and average depth to the water table (catchment). Despite a very small sample size owing to the rarity of A. heterodon, cross-validated prediction accuracy was 91%.
  4. Most predicted suitable segments occur in catchments not known to contain A. heterodon, which provides opportunities for new discoveries or population restoration. These model predictions can guide surveys toward the streams with the best chance of containing the species or, alternatively, away from those streams with little chance of containing A. heterodon.
  5. Developed reaches had low predicted suitability for A. heterodon in the Coastal Plain. Urban and exurban sprawl continues to modify stream ecosystems in the region, underscoring the need to preserve existing populations and to discover and protect new populations.

Local biotic adaptation of trees and shrubs to plant neighbors

Released March 14, 2017 00:00 EST

2017, Oikos

Kevin C. Grady, Troy E. Wood, Thomas E. Kolb, Erika Hersch-Green, Stephen M. Shuster, Catherine A. Gehring, Stephen C. Hart, Gerard J. Allan, Thomas G. Whitham

Natural selection as a result of plant–plant interactions can lead to local biotic adaptation. This may occur where species frequently interact and compete intensely for resources limiting growth, survival, and reproduction. Selection is demonstrated by comparing a genotype interacting with con- or hetero-specific sympatric neighbor genotypes with a shared site-level history (derived from the same source location), to the same genotype interacting with foreign neighbor genotypes (from different sources). Better genotype performance in sympatric than allopatric neighborhoods provides evidence of local biotic adaptation. This pattern might be explained by selection to avoid competition by shifting resource niches (differentiation) or by interactions benefitting one or more members (facilitation). We tested for local biotic adaptation among two riparian trees, Populus fremontii and Salix gooddingii, and the shrub Salix exigua by transplanting replicated genotypes from multiple source locations to a 17 000 tree common garden with sympatric and allopatric treatments along the Colorado River in California. Three major patterns were observed: 1) across species, 62 of 88 genotypes grew faster with sympatric neighbors than allopatric neighbors; 2) these growth rates, on an individual tree basis, were 44, 15 and 33% higher in sympatric than allopatric treatments for P. fremontii, S. exigua and S. gooddingii, respectively, and; 3) survivorship was higher in sympatric treatments for P. fremontiiand S. exigua. These results support the view that fitness of foundation species supporting diverse communities and dominating ecosystem processes is determined by adaptive interactions among multiple plant species with the outcome that performance depends on the genetic identity of plant neighbors. The occurrence of evolution in a plant-community context for trees and shrubs builds on ecological evolutionary research that has demonstrated co-evolution among herbaceous taxa, and evolution of native species during exotic plants invasion, and taken together, refutes the concept that plant communities are always random associations.

Evaluation of a method using survey counts and tag data to estimate the number of Pacific walruses (Odobenus rosmarus divergens) using a coastal haulout in northwestern Alaska

Released March 14, 2017 00:00 EST

2017, Polar Biology

Brian Battaile, Chadwick V. Jay, Mark S. Udevitz, Anthony S. Fischbach

Increased periods of sparse sea ice over the continental shelf of the Chukchi Sea in late summer have reduced offshore haulout habitat for Pacific walruses (Odobenus rosmarus divergens) and increased opportunities for human activities in the region. Knowing how many walruses could be affected by human activities would be useful to conservation decisions. Currently, there are no adequate estimates of walrus abundance in the northeastern Chukchi Sea during summer–early autumn. Estimating abundance in autumn might be possible from coastal surveys of hauled out walruses during periods when offshore sea ice is unavailable to walruses. We evaluated methods to estimate the size of the walrus population that was using a haulout on the coast of northwestern Alaska in autumn by using aerial photography to count the number of hauled out walruses (herd size) and data from 37 tagged walruses to estimate availability (proportion of population hauled out). We used two methods to estimate availability, direct proportions of hauled out tagged walruses and smoothed proportions using local polynomial regression. Point estimates of herd size (4200–38,000 walruses) and total population size (76,000–287,000 walruses) ranged widely among days and between the two methods of estimating availability. Estimates of population size were influenced most by variation in estimates of availability. Coastal surveys might be improved most by counting walruses when the greatest numbers are hauled out, thereby reducing the influence of availability on population size estimates. The chance of collecting data during peak haulout periods would be improved by conducting multiple surveys.

Egg deposition by lithophilic-spawning fishes in the Detroit and Saint Clair Rivers, 2005–14

Released March 14, 2017 00:00 EST

2017, Scientific Investigations Report 2017-5003

Carson G. Prichard, Jaquelyn M. Craig, Edward F. Roseman, Jason L. Fischer, Bruce A. Manny, Gregory W. Kennedy

A long-term, multiseason, fish egg sampling program conducted annually on the Detroit (2005–14) and Saint Clair (2010–14) Rivers was summarized to identify where productive fish spawning habitat currently exists. Egg mats were placed on the river bottom during the spring and fall at historic spawning areas and candidate fish spawning habitat restoration sites throughout both rivers. Widespread evidence was found of lithophilic spawning by numerous native fish species, including walleye (Sander vitreus), lake whitefish (Coregonus clupeaformis), lake sturgeon (Acipenser fulvescens), suckers (Catostomidae spp.), and trout-perch (Percopsis omiscomaycus). Walleye, lake whitefish, and suckers spp. spawned in nearly every region of each river in all years on both reef and nonreef substrates. Lake sturgeon eggs were collected almost exclusively over constructed reefs. Catch-per-unit effort of walleye, lake whitefish, and sucker eggs was much greater in the Detroit River than in the Saint Clair River, while Saint Clair River sites supported the greatest collections of lake sturgeon eggs. Collections during this study of lake sturgeon eggs on man-made spawning reefs suggest that artificial reefs may be an effective tool for restoring fish populations in the Detroit and Saint Clair Rivers; however, the quick response of lake sturgeon to spawn on newly constructed reefs and the fact that walleye, lake whitefish, and sucker eggs were often collected over substrate with little interstitial space to protect eggs from siltation and predators suggests that lack of suitable spawning habitat may continue to limit reproduction of lithophilic-spawning fish species in the Saint Clair-Detroit River System.

Geochemistry of host rocks in the Howards Pass district, Yukon-Northwest Territories, Canada: implications for sedimentary environments of Zn-Pb and phosphate mineralization

Released March 13, 2017 00:00 EST

2017, Mineralium Deposita (52) 565-593

John F. Slack, Hendrik Falck, Karen D. Kelley, Gabriel G. Xue

Detailed lithogeochemical data are reported here on early Paleozoic sedimentary rocks that host the large Howards Pass stratiform Zn-Pb deposits in Yukon-Northwest Territories. Redox-sensitive trace elements (Mo, Re, V, U) and Ce anomalies in members of the Duo Lake Formation record significant environmental changes. During the deposition of lower footwall units (Pyritic siliceous and Calcareous mudstone members), bottom waters were anoxic and sulphidic, respectively; these members formed in a marginal basin that may have become increasingly restricted with time. Relative to lower members, a major environmental change is proposed for deposition of the overlying Lower cherty mudstone member, which contains phosphorite beds up to ∼0.8 m thick in the upper part, near the base of the Zn-Pb deposits. The presence of these beds, together with models for modern phosphorite formation, suggests P input from an upwelling system and phosphorite deposition in an upper slope or outer shelf setting. The overlying Active mudstone member contains stratabound to stratiform Zn-Pb deposits within black mudstone and gray calcareous mudstone. Data for unmineralized black mudstone in this member indicate deposition under diverse redox conditions from suboxic to sulphidic. Especially distinctive in this member are uniformly low ratios of light to heavy rare earth elements that are unique within the Duo Lake Formation, attributed here to the dissolution of sedimentary apatite by downward-percolating acidic metalliferous brines. Strata that overlie the Active member (Upper siliceous mudstone member) consist mainly of black mudstone with thin (0.5–1.5 cm) laminae of fine-grained apatite, recording continued deposition on an upper slope or outer shelf under predominantly suboxic bottom waters. Results of this study suggest that exploration for similar stratiform sediment-hosted Zn-Pb deposits should include the outer parts of ancient continental margins, especially at and near stratigraphic transitions from marginal basin facies to overlying slope or shelf facies.

Territory occupancy and breeding success of Peregrine Falcons Falco peregrinus at various stages of population recovery

Released March 13, 2017 00:00 EST

2017, Ibis (159) 285-296

Michael J. McGrady, James Hines, Chris Rollie, George D. Smith, Elise R. Morton, Jennifer F. Moore, Richard M. Mearns, Ian Newton, Oscar E. Murillo-Garcia, Madan K. Oli

Organochlorine pesticides disrupted reproduction and killed many raptorial birds, and contributed to population declines during the 1940s to 1970s. We sought to discern whether and to what extent territory occupancy and breeding success changed from the pesticide era to recent years in a resident population of Peregrine Falcons Falco peregrinus in southern Scotland using long-term (1964–2015) field data and multi-state, multi-season occupancy models. Peregrine territories that were occupied with successful reproduction in one year were much more likely to be occupied and experience reproductive success in the following year, compared with those that were unoccupied or occupied by unsuccessful breeders in the previous year. Probability of territory occupancy differed between territories in the eastern and western parts of the study area, and varied over time. The probability of occupancy of territories that were unoccupied and those that were occupied with successful reproduction during the previous breeding season generally increased over time, whereas the probability of occupancy of territories that were occupied after failed reproduction decreased. The probability of reproductive success (conditional on occupancy) in territories that were occupied during the previous breeding season increased over time. Specifically, for territories that had been successful in the previous year, the probability of occupancy as well as reproductive success increased steadily over time; these probabilities were substantially higher in recent years than earlier, when the population was still exposed to direct or residual effects of organochlorine pesticides. These results are consistent with the hypothesis that progressive reduction, followed by a complete ban, in the use of organochlorine pesticides improved reproductive success of Peregrines in southern Scotland. Differences in the temporal pattern of probability of reproductive success between south-eastern and south-western Scotland suggest that the effect of organochlorine pesticides on Peregrine reproductive success and/or the recovery from pesticide effects varied geographically and was possibly affected by other factors such as persecution.

Relationships between maternal engorgement weight and the number, size, and fat content of larval Ixodes scapularis (Acari: Ixodidae)

Released March 13, 2017 00:00 EST

2017, Journal of Medical Entomology (54) 275-280

Howard Ginsberg, Chong Lee, Barry Volson, Megan C. Dyer, Roger A. LeBrun

The relationship between engorgement weight of female Ixodes scapularis Say and characteristics of offspring was studied using field-collected females fed on rabbits in the laboratory. The number of eggs laid was positively related to maternal engorgement weight in one trial, and larval size (estimated by scutal area) was positively related to maternal engorgement weight in the other. These results suggest a trade-off in number of eggs produced versus average size of offspring, possibly determined during late engorgement. The adults for the two trials were collected from different sites in southern Rhode Island and in different seasons (the fall adults were newly emerged, while the spring adults had presumably lived through the winter), so it is not clear whether these results reflect genetic differences or subtle environmental differences between trials. Percent egg hatch and average fat content of larvae were not related to female engorgement weight. We present a modified method to measure lipid content of pooled larval ticks.

Adjusting particle-size distributions to account for aggregation in tephra-deposit model forecasts

Released March 13, 2017 00:00 EST

2016, Atmospheric Chemistry and Physics (16) 9399-9420

Larry G. Mastin, Alexa Van Eaton, A.J. Durant

Volcanic ash transport and dispersion (VATD) models are used to forecast tephra deposition during volcanic eruptions. Model accuracy is limited by the fact that fine-ash aggregates (clumps into clusters), thus altering patterns of deposition. In most models this is accounted for by ad hoc changes to model input, representing fine ash as aggregates with density ρagg, and a log-normal size distribution with median μagg and standard deviation σagg. Optimal values may vary between eruptions. To test the variance, we used the Ash3d tephra model to simulate four deposits: 18 May 1980 Mount St. Helens; 16–17 September 1992 Crater Peak (Mount Spurr); 17 June 1996 Ruapehu; and 23 March 2009 Mount Redoubt. In 192 simulations, we systematically varied μagg and σagg, holding ρagg constant at 600 kg m−3. We evaluated the fit using three indices that compare modeled versus measured (1) mass load at sample locations; (2) mass load versus distance along the dispersal axis; and (3) isomass area. For all deposits, under these inputs, the best-fit value of μagg ranged narrowly between  ∼  2.3 and 2.7φ (0.20–0.15 mm), despite large variations in erupted mass (0.25–50 Tg), plume height (8.5–25 km), mass fraction of fine ( <  0.063 mm) ash (3–59 %), atmospheric temperature, and water content between these eruptions. This close agreement suggests that aggregation may be treated as a discrete process that is insensitive to eruptive style or magnitude. This result offers the potential for a simple, computationally efficient parameterization scheme for use in operational model forecasts. Further research may indicate whether this narrow range also reflects physical constraints on processes in the evolving cloud.

Coastal single-beam bathymetry data collected in 2015 from Raccoon Point to Point Au Fer Island, Louisiana

Released March 10, 2017 09:15 EST

2017, Data Series 1041

Chelsea A. Stalk, Nancy T. DeWitt, Jack L. Kindinger, James G. Flocks, Billy J. Reynolds, Kyle W. Kelso, Joseph J. Fredericks, Thomas M. Tuten

As part of the Barrier Island Comprehensive Monitoring Program (BICM), scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted a nearshore single-beam bathymetry survey along the south-central coast of Louisiana, from Raccoon Point to Point Au Fer Island, in July 2015. The goal of the BICM program is to provide long-term data on Louisiana’s coastline and use this data to plan, design, evaluate, and maintain current and future barrier island restoration projects. The data described in this report will provide baseline bathymetric information for future research investigating island evolution, sediment transport, and recent and long-term geomorphic change, and will support modeling of future changes in response to restoration and storm impacts. The survey area encompasses more than 300 square kilometers of nearshore environment from Raccoon Point to Point Au Fer Island. This data series serves as an archive of processed single-beam bathymetry data, collected from July 22–29, 2015, under USGS Field Activity Number 2015-320-FA. Geographic information system data products include a 200-meter-cell-size interpolated bathymetry grid, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.

Input data to run Landis-II

Released March 10, 2017 00:00 EST

2017, Dataset

Nathan R. DeJager

The data are input data files to run the forest simulation model Landis-II for Isle Royale National Park. Files include: a) Initial_Comm, which includes the location of each mapcode, b) Cohort_ages, which includes the ages for each tree species-cohort within each mapcode, c) Ecoregions, which consist of different regions of soils and climate, d) Ecoregion_codes, which define the ecoregions, and e) Species_Params, which link the potential establishment and growth rates for each species with each ecoregion.

Natural resource inventory and monitoring for Ulaan Taiga Specially Protected Areas—An assessment of needs and opportunities in northern Mongolia

Released March 10, 2017 00:00 EST

2017, Open-File Report 2017-1025

Peggy E. Moore, Joseph B. Meyer, Leslie S. Chow

Between 1997 and 2011, Mongolia established three specially protected areas in the north-central part of the country to protect various high-value resources. These areas are jointly referred to as the Ulaan Taiga Specially Protected Areas. In accordance with the goals of the draft general management plan, this report identifies options for initiating an inventory and monitoring program for the three protected areas. Together, the three areas comprise over 1.5 million hectares of mountainous terrain west of Lake Hovsgol and bordering the Darkhad Valley. The area supports numerous rare ungulates, endangered fish, and over 40 species of threatened plants. Illegal mining, illegal logging, and poaching pose the most immediate threats to resources. As a first step, a review of published literature would inform natural resource management at the Ulaan Taiga Specially Protected Areas because it would inform other inventories.

Vegetation classification and mapping also would inform other inventory efforts because the process incorporates geographic analysis to identify environmental gradients, fine-scale sampling that captures species composition and structure, and landscape-scale results that represent the variety and extent of habitats for various organisms. Mapping using satellite imagery reduces the cost per hectare.

Following a determination of existing knowledge, field surveys of vertebrates and vascular plants would serve to build species lists and fill in gaps in existing knowledge. For abiotic resources, a focus on monitoring air quality, evaluating and monitoring water quality, and assembling and storing weather data would provide information for correlating resource response status with changing environmental conditions.

Finally, we identify datasets that, if incorporated into a geographic information system, would inform resource management. They include political boundaries, infrastructure, topography, surficial geology, hydrology, fire history, and soils.

In terms of tracking high-value resources, vegetation monitoring at the plot scale would provide a basis for detecting change in such characteristics as plant species composition, vegetation structure, and productivity that are associated with landscape-scale factors such as climate change or biotic interactions. Continued population monitoring of rare ungulates, particularly argali or wild sheep (Ovis ammon), would provide information on how populations are responding to natural and anthropogenic stressors. Siberian taimen (Hucho taimen) also is an important monitoring target given ongoing threats of poaching and climate change.

Ascii grids of predicted pH in depth zones used by domestic and public drinking water supply depths, Central Valley, California

Released March 10, 2017 00:00 EST

2017, Dataset

Celia Zamora, Bernard T. Nolan, JoAnn M. Gronberg

The ascii grids associated with this data release are predicted distributions of continuous pH at the drinking water depth zones in the groundwater of Central Valley, California. The two prediction grids produced in this work represent predicted pH at the domestic supply and public supply drinking water depths, respectively and are bound by the alluvial boundary that defines the Central Valley. A depth of 46 m was used to stratify wells into the shallow and deep aquifer and were derived from depth percentiles associated with domestic and public supply in previous work by Burow et al. (2013). In this work, the median well depth categorized as domestic supply was 30 meters below land surface and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically Boosted Regression Trees (BRT) with a gaussian error distribution within a statistical learning framework within R's computing framework ( The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1337 wells, and was compiled from two sources: US Geological Survey (USGS) National Water Information System (NWIS) Database (all data are publicly available from the USGS: and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993-2014 was used. A total of 1003 wells (training dataset) were used to train the BRT model and 334 wells (hold-out dataset) were used to validate the prediction model. The training r-squared was 0.70 and the RMSE in standard pH units was were 0.26. The holdout r-squared was 0.43 and RMSE in standard pH units was 0.37. Predictor variables consisting of more than 60 variables from 7 sources (see metadata) were assembled to develop a model that incorporates regional-scale soil properties, soil chemistry, land use, aquifer textures, and aquifer hydrology. Previously developed Central Valley model outputs of textures (Central Valley Textural Model, CVTM; Faunt et al. 2010) and MODFLOW-simulated vertical water fluxes and predicted depth to water table (Central Valley Hydrologic Model, CVHM; Faunt, 2009) were used to represent aquifer textures and groundwater hydraulics, respectively. In this work, wells were attributed to predictor variable values in ArcGIS using a 500-m buffer. Results of the predictor variable influence as defined by Friedman (2001) for variables used in the final BRT model used for mapping can be downloaded from this landing page (see file named PredictorVariableInfluence_CentralValley_pH_BRT.csv).

Demographic rates and population viability of black bears in Louisiana

Released March 10, 2017 00:00 EST

2015, Wildlife Monographs (194) 1-37

Jared S. Laufenberg, Joseph D. Clark, Michael J. Hooker, Carrie L. Lowe, Kaitlin C. O'Connell-Goode, Jesse C. Troxler, Maria M. Davidson, Michael J. Chamberlain, Richard B. Chandler

The Louisiana black bear (Ursus americanus luteolus) was reduced to a few small, fragmented, and isolated subpopulations in the Lower Mississippi Alluvial Valley by the mid-twentieth century resulting from loss and fragmentation of habitat. In 1992, the United States Fish and Wildlife Service (USFWS) granted the Louisiana black bear threatened status under the United States Endangered Species Act of 1973. Since that time, a recovery plan was developed, a reintroduced population was established, and habitat recovery has occurred. The Recovery Plan states that a minimum of 2 populations must be viable (i.e., persistence probabilities over 100 years >0.95), 1 in the Tensas River Basin and 1 in the Atchafalaya River Basin. Consequently, our objectives were to 1) estimate demographic rates of Louisiana black bear subpopulations, 2) develop data-driven stochastic population projection models, and 3) determine how different projection model assumptions affect population trajectories and predictions about long-term persistence. Our overall goal was to assess long-term persistence of the bear subpopulations in Louisiana, individually and as a whole. We collected data using varying combinations of non-invasive DNA sampling, live capture, winter den visits, and radio monitoring from 2002 to 2012 in the 4 areas currently supporting breeding subpopulations in Louisiana: Tensas River Basin (TRB), Upper Atchafalaya River Basin (UARB), Lower Atchafalaya River Basin (LARB), and a recently reintroduced population at the Three Rivers Complex (TRC). From 2002 to 2012, we radio monitored fates of 86 adult females within the TRB and 43 in the TRC. Mean estimates of annual adult survival for the TRB and TRC were 0.997 and 0.990, respectively, when unknown fates were assumed alive and 0.970 and 0.926 when unknown fates were assumed dead. From 2003 to 2013, we observed 130 cub litters from 74 females in the TRB, and 74 cub litters from 45 females in the TRC. During the same period, we observed 43 yearling litters for 33 females in the TRB and 21 yearling litters for 19 females in the TRC. The estimated number of cubs and number of yearlings produced per breeding adult female was 0.47 and 0.20, respectively, in the TRB and 0.32 and 0.18 in the TRC. On the basis of matrix projection models, asymptotic growth rates ranged from 1.053 to 1.078 for the TRB and from 1.005 to 1.062 for the TRC, depending on how we treated unresolved fates of adult females. Persistence probabilities estimated from stochastic population models based on telemetry data ranged from 0.997 to 0.998 for the TRC subpopulation depending on model assumptions and were >0.999 for the TRB regardless of model assumptions. We extracted DNA from hair collected at baited, barbed-wire enclosures in the TRB, UARB, and LARB to determine individual identities for capture-mark-recapture (CMR) analysis. We used those detection histories to estimate apparent survival (φ), per-capita recruitment (f), abundance (N), realized growth rate (λ), and long-term viability, based on Bayesian hierarchical modeling methods that allowed estimation of temporal process variance and parameter uncertainty. Based on 23,312 hair samples, annual N for females in the TRB ranged from 133 to 164 during 2006–2012, depending on year and how detection heterogeneity was modeled. Geometric mean of λ ranged from 0.996 to 1.002. In the UARB, we collected 11,643 hair samples from 2007 to 2012, from which estimates of N for females ranged from 23 to 43 during the study period, depending on detection heterogeneity model. The geometric mean of λ ranged from 1.038 to 1.059. Estimated N for females in LARB ranged from 69 to 96, and annual λ ranged from 0.80 to 1.11 based on 3,698 hair samples collected during 2010–2012, also depending on year and heterogeneity model. Probabilities of persistence over 100 years for the TRC and TRB based on stochastic matrix projection models that used vital rate estimates from telemetry data were >0.95 for all scenarios. Probability of persistence at the TRB and the UARB based on projection models that used vital rate estimates from CMR analyses ranged from 0.928 to 0.954 and from 0.906 to 0.959, respectively, depending on model assumptions. Data from the LARB were insufficient for a viability assessment. Thus, individual persistence probabilities for TRB and UARB did not meet the strict definition of viability (i.e., >0.95) under some model assumptions. However, the joint probability of bears persisting either in the TRB or UARB was >0.993 assuming individual population dynamics were independent and was >0.958 assuming dynamics were perfectly correlated. Furthermore, including the TRC increased the joint probability of bears persisting somewhere in the TRB, UARB, or TRC to >0.999 based on the most pessimistic individual persistence estimates from those subpopulations. Therefore, if the intent of specifying that 2 subpopulations should be viable was to ensure the persistence of Louisiana black bears somewhere within its historical range, then the viability threshold was met. © 2016 The Wildlife Society.

Structured decision making as a conservation tool for recovery planning of two endangered salamanders

Released March 09, 2017 00:00 EST

2017, Journal for Nature Conservation

Katherine O'Donnell, Arianne F Messerman, William J. Barichivich, Raymond D. Semlitsch, Thomas A. Gorman, Harold G Mitchell, Nathan Allan, Dante B. Fenolio, Adam Green, Fred A. Johnson, Allison Keever, Mark Mandica, Julien Martin, Jana Mott, Terry Peacock, Joseph Reinman, Stephanie Romanach, Greg Titus, Conor McGowan, Susan Walls

At least one-third of all amphibian species face the threat of extinction, and current amphibian extinction rates are four orders of magnitude greater than background rates. Preventing extirpation often requires both ex situ (i.e., conservation breeding programs) and in situ strategies (i.e., protecting natural habitats). Flatwoods salamanders (Ambystoma bishopi and A. cingulatum) are protected under the U.S. Endangered Species Act. The two species have decreased from 476 historical locations to 63 recently extant locations (86.8% loss). We suggest that recovery efforts are needed to increase populations and prevent extinction, but uncertainty regarding optimal actions in both ex situ and in situ realms hinders recovery planning. We used structured decision making (SDM) to address key uncertainties regarding both captive breeding and habitat restoration, and we developed short-, medium-, and long-term goals to achieve recovery objectives. By promoting a transparent, logical approach, SDM has proven vital to recovery plan development for flatwoods salamanders. The SDM approach has clear advantages over other previous approaches to recovery efforts, and we suggest that it should be considered for other complex decisions regarding endangered species.

Putting flow-ecology relationships into practice: A decision-support system to assess fish community response to water-management scenarios

Released March 09, 2017 00:00 EST

2017, Water (9) 1-18

Jennifer M. Cartwright, Casey Caldwell, Steven Nebiker, Rodney Knight

This paper presents a conceptual framework to operationalize flow–ecology relationships into decision-support systems of practical use to water-resource managers, who are commonly tasked with balancing multiple competing socioeconomic and environmental priorities. We illustrate this framework with a case study, whereby fish community responses to various water-management scenarios were predicted in a partially regulated river system at a local watershed scale. This case study simulates management scenarios based on interactive effects of dam operation protocols, withdrawals for municipal water supply, effluent discharges from wastewater treatment, and inter-basin water transfers. Modeled streamflow was integrated with flow–ecology relationships relating hydrologic departure from reference conditions to fish species richness, stratified by trophic, reproductive, and habitat characteristics. Adding a hypothetical new water-withdrawal site was predicted to increase the frequency of low-flow conditions with adverse effects for several fish groups. Imposition of new reservoir release requirements was predicted to enhance flow and fish species richness immediately downstream of the reservoir, but these effects were dissipated further downstream. The framework presented here can be used to translate flow–ecology relationships into evidence-based management by developing decision-support systems for conservation of riverine biodiversity while optimizing water availability for human use.

Groundwater-quality data in 12 GAMA study units: Results from the 2006–10 initial sampling period and the 2008–13 trend sampling period, California GAMA Priority Basin Project

Released March 09, 2017 00:00 EST

2017, Data Series 1038

Timothy M. Mathany

The Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) program was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey in cooperation with the California State Water Resources Control Board. From 2004 through 2012, the GAMA-PBP collected samples and assessed the quality of groundwater resources that supply public drinking water in 35 study units across the State. Selected sites in each study unit were sampled again approximately 3 years after initial sampling as part of an assessment of temporal trends in water quality by the GAMA-PBP. Twelve of the study units, initially sampled during 2006–11 (initial sampling period) and sampled a second time during 2008–13 (trend sampling period) to assess temporal trends, are the subject of this report.

The initial sampling was designed to provide a spatially unbiased assessment of the quality of untreated groundwater used for public water supplies in the 12 study units. In these study units, 550 sampling sites were selected by using a spatially distributed, randomized, grid-based method to provide spatially unbiased representation of the areas assessed (grid sites, also called “status sites”). After the initial sampling period, 76 of the previously sampled status sites (approximately 10 percent in each study unit) were randomly selected for trend sampling (“trend sites”). The 12 study units sampled both during the initial sampling and during the trend sampling period were distributed among 6 hydrogeologic provinces: Coastal (Northern and Southern), Transverse Ranges and Selected Peninsular Ranges, Klamath, Modoc Plateau and Cascades, and Sierra Nevada Hydrogeologic Provinces. For the purposes of this trend report, the six hydrogeologic provinces were grouped into two hydrogeologic regions based on location: Coastal and Mountain.

The groundwater samples were analyzed for a number of synthetic organic constituents (volatile organic compounds, pesticides, and pesticide degradates), constituents of special interest (perchlorate and 1,2,3-trichloropropane), and natural inorganic constituents (nutrients, major and minor ions, and trace elements). Isotopic tracers (tritium, carbon-14, and stable isotopes of hydrogen and oxygen in water) also were measured to help identify processes affecting groundwater quality and the sources and ages of the sampled groundwater. More than 200 constituents and water-quality indicators were measured during the trend sampling period.

Quality-control samples (blanks, replicates, matrix-spikes, and surrogate compounds) were collected at about one-third of the trend sites, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. On the basis of detections in laboratory and field blank samples collected by GAMA-PBP study units, including the 12 study units presented here, reporting levels for some groundwater results were adjusted in this report. Differences between replicate samples were mostly within acceptable ranges, indicating low variability in analytical results. Matrix-spike recoveries were largely within the acceptable range (70 to 130 percent).

This study did not attempt to evaluate the quality of water delivered to consumers. After withdrawal, groundwater used for drinking water typically is treated, disinfected, and blended with other waters to achieve acceptable water quality. The comparison benchmarks used in this report apply to treated water that is served to the consumer, not to untreated groundwater. To provide some context for the results, however, concentrations of constituents measured in these groundwater samples were compared with benchmarks established by the U.S. Environmental Protection Agency and the State of California. Comparisons between data collected for this study and benchmarks for drinking water are for illustrative purposes only and are not indicative of compliance or non-compliance with those benchmarks.

Most organic constituents that were detected in groundwater samples from the trend sites were found at concentrations less than health-based benchmarks. One volatile organic compound—perchloroethene—was detected at a concentration greater than the health-based benchmark in samples from one trend site during the initial and trend sampling periods. Chloroform was detected in at least 10 percent of the samples at trend sites in both sampling periods. Methyl tert-butyl ether was detected in samples from more than 10 percent of the trend sites during the initial sampling period. No pesticide or pesticide degradate was detected in greater than 10 percent of the samples from trend sites or at concentrations greater than their health-based benchmarks during either sampling period. Nutrients were not detected at concentrations greater than their health-based benchmarks during either sampling period.

Most detections of major ions and trace elements in samples from trend sites were less than health-based benchmarks during both sampling periods. Arsenic and boron each were detected at concentrations greater than the health-based benchmark in samples from four trend sites during the initial and trend sampling periods. Molybdenum was detected in samples from four trend sites at concentrations greater than the health-based benchmark during both sampling periods. Samples from two of these trend sites had similar molybdenum concentrations, and two had substantially different concentrations during the initial and trend sampling periods. Uranium was detected at a concentration greater than the health-based benchmark only at two trend sites.

Geology and mining history of the Southeast Missouri Barite District and the Valles Mines, Washington, Jefferson, and St. Francois Counties, Missouri

Released March 09, 2017 00:00 EST

2017, Scientific Investigations Report 2016-5173

Douglas N. Mugel

The Southeast Missouri Barite District and the Valles Mines are located in Washington, Jefferson, and St. Francois Counties, Missouri, where barite and lead ore are present together in surficial and near-surface deposits. Lead mining in the area began in the early 1700’s and extended into the early 1900’s. Hand mining of lead in the residuum resulted in widespread pits (also called shafts or diggings), and there was some underground mining of lead in bedrock. By the 1860’s barite was recovered from the residuum by hand mining, also resulting in widespread diggings, but generally not underground mines in bedrock. Mechanized open-pit mining of the residuum for barite began in the 1920’s. Barite production slowed by the 1980’s, and there has not been any barite mining since 1998. Mechanized barite mining resulted in large mined areas and tailings ponds containing waste from barite mills.

The U.S. Environmental Protection Agency (EPA) has determined that lead is present in surface soils in Washington and Jefferson Counties at concentrations exceeding health-based screening levels. Also, elevated concentrations of barium, arsenic, and cadmium have been identified in surface soils, and lead concentrations exceeding the Federal drinking-water standard of 15 micrograms per liter have been identified in private drinking-water wells. Potential sources of these contaminants are wastes associated with barite mining, wastes associated with lead mining, or unmined natural deposits of barium, lead, and other metals. As a first step in helping EPA determine the source of soil and groundwater contamination, the U.S. Geological Survey (USGS), in cooperation with the EPA, investigated the geology and mining history of the Southeast Missouri Barite District and the Valles Mines.

Ore minerals are barite (barium sulfate), galena (lead sulfide), cerussite (lead carbonate), anglesite (lead sulfate), sphalerite (zinc sulfide), smithsonite (zinc carbonate), and chalcopyrite (copper-iron sulfide). The Cambrian Potosi Dolomite is the most important formation for the ore deposits, followed by the Eminence Dolomite. Because galena, sphalerite, and barite are less soluble than dolomite, chemical weathering of the ore-bearing dolomite bedrock resulted in the concentration of ore minerals in the residuum. Most of the barite and lead mining was in the residuum, which averages 10 to 15 feet thick.

Lead mining by French explorers may have begun in 1719 along Old Mines Creek at Cabanage de Renaudiere, which was followed shortly by the discovery of lead and the development of lead mines at Mine Renault (also called Forche a Renault Mine), Old Mines, and at other places along the Big River, Mineral Fork, and Forche a Renault Creek. Lead mining began sometime between 1775 and 1780 at Mine a Breton, the name of which was later changed to Potosi. Other mining areas were developed in the early part of the 19th century, including Fourche a Courtois (Palmer Mines), the French Diggings, and the Richwoods Mines. Zinc became a valuable resource after the Civil War, and the Valles Mines was an important supplier of zinc as well as lead, with at least some production up until the 1920’s. Lead mining declined in the early part of the 20th century as mining in the Old Lead Belt, Mine La Motte, and the Tri-State District expanded.

The earliest lead mines were diggings in the residuum and were round holes (shafts) about 4 feet in diameter dug with pick and shovel about 15–20 feet deep, with drifts dug a short distance laterally from the bottom of the shafts. This mining process was repeated a short distance away until a large area was covered with pits. Some mining in bedrock began by about 1800, with shafts as deep as 170 feet and as much as several hundred feet of lateral drifts.

Smelting of the lead ore to elemental lead was first done using a log furnace, which was inefficient; estimates have been made that only about 50 percent of the lead was recovered, and the remainder was lost to the ashes (slags) and to volatilization. Starting in 1798, ash furnaces were used to smelt the ashes from the log furnaces. These two furnaces were worked in tandem for many years but were gradually replaced by other furnaces, including the Scotch hearth. Estimates of lead recovery as high as 80–90 percent have been made for the Scotch hearth. By the mid-1870’s the air furnace was being used, also with estimated lead recovery as high as 80–90 percent. Zinc furnaces were built when zinc became a valuable commodity, but much of the zinc ore was shipped out of the area, either to a smelter in St. Louis, Missouri, or to other smelters.

The total lead and zinc production from the Southeast Missouri Barite District and the Valles Mines is estimated at 180,000 tons of lead and 60,000 tons of zinc. An estimated 97,000 tons of lead and an estimated 120,000 tons of zinc were lost during smelting. The estimated losses do not include losses at the mine site during mining and preparation for smelting, such as the loss of fine-grained galena during hand cleaning or the discarding of zinc ore before its value was known, for which no estimates are available.

Hand mining for barite in the residuum was active by at least the 1860’s and peaked from 1905 to the 1930’s when several thousand people were engaged in barite mining. Hand mining (diggings) and cleaning of the ore was done in much the same way as earlier lead mining, with the additional use of a rattle box to further clean the barite. Mechanized open-pit mining of old barite diggings began in 1924 to recover barite left behind by hand mining, and washing plants were used to clean the clay from the barite. Hand mining, however, continued to thrive, and washer plants began to close temporarily in 1931; nearly all of the barite produced before 1937 was by hand mining. By the 1940’s, however, all barite mining was mechanized.

Mechanized mining used shovels powered by steam, gasoline, or electricity (and by the 1950’s draglines and front-end loaders) to mine the residuum. The ore was loaded onto rail cars (and by the 1940’s, trucks) for shipment to washer plants. Clay was removed from the barite using a log washer, and a jig was used to concentrate the barite. Overflow from the log washers was waste and went to a mud (tailings) pond. The coarse jig tailings went to tailings piles or were used as railroad ballast and, later, to create roads within the mine pit. Some barite was ground, depending on its final use, and some ground barite was bleached using a hot solution of sulfuric acid to remove impurities such as iron minerals and lead sulfide (galena). An earlier bleaching process used lead-lined tanks.

Large quantities of water were required for milling the barite; some was recirculated water and the remainder came from dammed streams or was pumped from wells. Tailings and wastewater were impounded behind dikes that were built across small valleys and were increased in height as necessary using washer waste and any overburden that had been stripped. In some cases, dikes were built across valleys that had already been mined for barite.

The total production of barite from the Southeast Missouri Barite District and the Valles Mines is estimated to have been about 13.1 million tons. Most of the barite production was from Washington County. Hand mining and processing of barite was inefficient. Estimates of barite recovery range from less than one-fourth to about one-half because pillars between the shafts in the residuum needed to be left unmined for stability. With mechanized mining, large amounts of barite were lost during the milling process. It has been estimated that about 30 percent of the barite was lost and that about two-thirds of the lost barite was fine-grained and was discharged to the tailings ponds. Some galena was lost to the tailings ponds.

A 1972 inventory of tailings ponds by the Missouri Geological Survey identified 67 ponds in the Southeast Missouri Barite District (there are more than this currently documented). Results from samples from four ponds that were drilled were used to estimate that the 67 ponds contained almost 39 million tons (or cubic yards) of tailings averaging about 5 percent barite, for a potential reserve of 1.935 million tons of barite.

It is not known how much lead was removed during barite mining, either by hand or mechanized mining and processing, how much lead was recovered, or how much lead went as fines to the tailing ponds or as coarse material to mine roads or was otherwise lost.

Sediment data collected in 2014 and 2015 from around Breton and Gosier Islands, Breton National Wildlife Refuge, Louisiana

Released March 08, 2017 11:30 EST

2017, Data Series 1037

Julie C. Bernier, Kyle W. Kelso, Thomas M. Tuten, Chelsea A. Stalk, James G. Flocks

Breton Island, located at the southern end of the Chandeleur Islands, supports one of Louisiana’s largest historical brown pelican (Pelecanus occidentalis) nesting colonies. Although the brown pelican was delisted as an endangered species in 2009, nesting areas are threatened by continued land loss and are extremely vulnerable to storm impacts. The U.S. Fish and Wildlife Service proposed to restore Breton Island to pre-Hurricane Katrina conditions through rebuilding the shoreface, dune, and back-barrier marsh environments. Prior to restoration, scientists from the U.S. Geological Survey’s (USGS) St. Petersburg Coastal and Marine Science Center Geologic and Morphologic Evolution of Coastal Margins project collected high-resolution geophysical (topography, bathymetry, and sub-bottom profiles) and sedimentologic data from around Breton Island to characterize the geologic framework of the island platform, nearshore, and shelf environments. These data will be used to characterize the geologic framework around Breton Island, identify potential borrow areas for restoration efforts, quantify seafloor change, and provide information for sediment transport and morphologic change models to assess island response to restoration and natural processes.

This report, along with the accompanying USGS data release, serves as an archive of sediment data from vibracores, push cores, and submerged grab samples collected from around Breton and Gosier Islands, Louisiana, during two surveys conducted in July 2014 and January 2015 (USGS Field Activity Numbers 2014–314–FA and 2014–336–FA, respectively). Sedimentologic and stratigraphic metrics (for example, sediment texture or unit thicknesses) derived from these data can be used to ground-truth the geophysical data and characterize potential sand resources or can be incorporated into sediment transport or morphologic change models. Data products, including sample location tables, descriptive core logs, core photographs and x-radiographs, results of sediment grain-size analyses, and geographic information system data files with accompanying formal Federal Geographic Data Committee metadata can be downloaded from the accompanying data release.

Importance of the 2014 Colorado River Delta pulse flow for migratory songbirds: Insights from foraging behavior

Released March 08, 2017 00:00 EST

2017, Ecological Engineering

Abigail J. Darrah, Harold F. Greeney, Charles Van Riper

The Lower Colorado River provides critical riparian areas in an otherwise arid region and is an important stopover site for migrating landbirds. In order to reverse ongoing habitat degradation due to drought and human-altered hydrology, a pulse flow was released from Morelos Dam in spring of 2014, which brought surface flow to dry stretches of the Colorado River in Mexico. To assess the potential effects of habitat modification resulting from the pulse flow, we used foraging behavior of spring migrants from past and current studies to assess the relative importance of different riparian habitats. We observed foraging birds in 2000 and 2014 at five riparian sites along the Lower Colorado River in Mexico to quantify prey attack rates, prey attack maneuvers, vegetation use patterns, and degree of preference for fully leafed-out or flowering plants. Prey attack rate was highest in mesquite (Prosopis spp.) in 2000 and in willow (Salix gooddingii) in 2014; correspondingly, migrants predominantly used mesquite in 2000 and willow in 2014 and showed a preference for willows in flower or fruit in 2014. Wilson’s warbler (Cardellina pusilla) used relatively more low-energy foraging maneuvers in willow than in tamarisk (Tamarix spp.) or mesquite. Those patterns in foraging behavior suggest native riparian vegetation, and especially willow, are important resources for spring migrants along the lower Colorado River. Willow is a relatively short-lived tree dependent on spring floods for dispersal and establishment and thus spring migrants are likely to benefit from controlled pulse flows.

Effects of carbon dioxide on juveniles of the freshwater mussel (Lampsilis siliquoidea [Unionidae])

Released March 08, 2017 00:00 EST

2017, Environmental Toxicology and Chemistry (36) 671-681

Diane L. Waller, Michelle Bartsch, Kim Fredricks, Lynn Bartsch, Sue M. Schleis, Sheldon Lee

Carbon dioxide (CO2) has shown promise as a tool to control movements of invasive Asian carp, but its effects on native freshwater biota have not been well studied. The authors evaluated lethal and sublethal responses of juvenile fatmucket (Lampsilis siliquoidea) mussels to CO2 at levels (43–269 mg/L, mean concentration) that bracket concentrations effective for deterring carp movement. The 28-d lethal concentration to 50% of the mussels was 87.0 mg/L (95% confidence interval [CI] 78.4–95.9) and at 16-d postexposure, 76.0 mg/L (95% CI 62.9–90.3). A proportional hazards regression model predicted that juveniles could not survive CO2 concentrations >160 mg/L for more than 2 wk or >100 mg/L CO2 for more than 30 d. Mean shell growth was significantly lower for mussels that survived CO2 treatments. Growth during the postexposure period did not differ among treatments, indicating recovery of the mussels. Also, CO2 caused shell pitting and erosion. Behavioral effects of CO2 included movement of mussels to the substrate surface and narcotization at the highest concentrations. Mussels in the 110 mg/L mean CO2treatment had the most movements in the first 3 d of exposure. If CO2 is infused continuously as a fish deterrent, concentrations <76 mg/L are recommended to prevent juvenile mussel mortality and shell damage. Mussels may survive and recover from brief exposure to higher concentrations.

Restoration versus invasive species: Bigheaded carps’ use of a rehabilitated backwater

Released March 08, 2017 00:00 EST

2017, River Research and Applications

Alison A Coulter, Douglas Schultz, Elizabeth Tristano, Marybeth Brey, James E. Garvey

Knowledge of how invasive species use invaded habitats can aid in developing management practices to exclude them. Swan Lake, a 1100-ha Illinois River (USA) backwater, was rehabilitated to restore ecosystem functions, but may provide valuable habitat for invasive bigheaded carps [bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix)]. Use (residency and passages) of Swan Lake by invasive bigheaded carps was monitored using acoustic telemetry (n = 50 individuals/species) to evaluate the use of a large, restored habitat from 2004 to 2005. Passages (entrances/exits) by bigheaded carps were highest in winter, and residency was highest in the summer. Bighead carp backwater use was associated with the differences in temperature between the main channel and backwater, and passages primarily occurred between 18:00 h and midnight. Silver carp backwater use was positively correlated with water level and main channel discharge, and fewer passages occurred between 12:00 h and 18:00 h than during any other time of day. Harvest occurring during summer or high main channel discharge could reduce backwater abundances while maintenance of low water levels could reduce overall backwater use. Conclusions from this study regarding the timing of bigheaded carps' use of backwater habitats are critical to integrated pest management plans to control invasive species.

Dam metrics representing stream fragmentation and flow alteration for the conterminous United States linked to the NHDPLUSV1

Released March 08, 2017 00:00 EST

2017, Dataset

Arthur R. Cooper, Dana M. Infante

This CSV file contains 21 dam metrics representing stream fragmentation and flow alteration for nearly 2.3 million stream reaches in the conterminous USA. Dam metrics fall into four main categories: segment-based, count and density, distance-based, and cumulative reservoir storage (described below). These data were developed using spatially verified large dam locations (n=49,468) primarily from the National Anthropogenic Barrier Dataset (NABD) that were spatially linked to the National Hydrography Dataset Plus version 1 (NHDPlusV1). These dam metrics have been summarized using the unique identifier field native to the NHDPlusV1 (COMID) which can be used to join this table to spatial layers and data tables of the NHDPlusV1. Non-fluvial features in the NHDPlusV1 (lake and reservoir flow paths, coastlines, etc.) are excluded (see NFHP metadata). Please contact Arthur Cooper ( for a copy of the publication associated with this data: Cooper, A.R., Infante, D.M., Daniel, W.M., Wehrly, K.E., Wang, L., Brenden, T.O. 2017. Assessment of dam effects for streams and fish assemblages of the conterminous USA. Science of the Total Environment doi:10.1016/j.scitotenv.2017.02.067

Gulf Watch Alaska nearshore component: Monitoring site locations from Prince William Sound, Katmai National Park and Preserve, and Kenai Fjords National Park

Released March 08, 2017 00:00 EST

2017, Dataset

Heather A. Coletti, Kim Kloecker, James L. Bodkin, Thomas A. Dean

These data are part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. Specifically, these data describe site locations for rocky intertidal, mussel sampling, soft sediment bivalve sampling, and eelgrass bed sampling in the northern Gulf of Alaska within the GWA program. The dataset consists of two comma separated files exported from a Microsoft Excel workbook. The data consists of 1. rocky intertidal, mussel sampling, and soft sediment site location information, and 2. eelgrass bed locations. Sampling will be conducted in Katmai National Park and Preserve (KATM), Kenai Fjords National Park (KEFJ), Prince William Sound (PWS) and to a lesser extent on the Lake Clark National Park and Preserve (LACL). Sites from a related project that provides similar data from Kachemak Bay (KBAY) are included here.

Predicted pH at the domestic and public supply drinking water depths, Central Valley, California

Released March 08, 2017 00:00 EST

2017, Scientific Investigations Map 3377

Celia Z. Rosecrans, Bernard T. Nolan, Jo Ann M. Gronberg

This scientific investigations map is a product of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project modeling and mapping team. The prediction grids depicted in this map are of continuous pH and are intended to provide an understanding of groundwater-quality conditions at the domestic and public supply drinking water zones in the groundwater of the Central Valley of California. The chemical quality of groundwater and the fate of many contaminants is often influenced by pH in all aquifers. These grids are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to pH. In this work, the median well depth categorized as domestic supply was 30 meters below land surface, and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically boosted regression trees (BRT) with a Gaussian error distribution within a statistical learning framework within the computing framework of R ( The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1,337 wells and was compiled from two sources: USGS National Water Information System (NWIS) database (all data are publicly available from the USGS: and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993–2014 was used. A total of 1,003 wells (training dataset) were used to train the BRT model, and 334 wells (hold-out dataset) were used to validate the prediction model. The training r-squared was 0.70, and the root-mean-square error (RMSE) in standard pH units was 0.26. The hold-out r-squared was 0.43, and RMSE in standard pH units was 0.37. Predictor variables consisting of more than 60 variables from 7 sources were assembled to develop a model that incorporates regional-scale soil properties, soil chemistry, land use, aquifer textures, and aquifer hydrology. Previously developed Central Valley model outputs of textures (Central Valley Textural Model, CVTM; Faunt and others, 2010) and MODFLOW-simulated vertical water fluxes and predicted depth to water table (Central Valley Hydrologic Model, CVHM; Faunt, 2009) were used to represent aquifer textures and groundwater hydraulics, respectively. In this work, wells were attributed to predictor variable values in ArcGIS using a 500-meter buffer.

Faunt, C.C., ed., 2009, Groundwater availability in the Central Valley aquifer, California: U.S. Geological Survey Professional Paper 1776, 225 p., accessed at

Faunt, C.C., Belitz, K., and Hanson, R.T., 2010, Development of a three-dimensional model of sedimentary texture in valley-fill deposits of Central Valley, California, USA: Hydrogeology Journal, v. 18, no. 3, p. 625–649,

2017 one-year seismic hazard forecast for the central and eastern United States from induced and natural earthquakes

Released March 08, 2017 00:00 EST

2017, Dataset

Mark D. Petersen, Charles Mueller, Morgan P. Moschetti, Susan M. Hoover, Allison Shumway, Daniel E. McNamara, Robert A. Williams, Andrea L. Llenos, William L. Ellsworth, Andrew J. Michael, Justin L. Rubinstein, Arthur F. McGarr, Kenneth S. Rukstales

We produce the 2017 one-year seismic hazard forecast for the central and eastern United States from induced and natural earthquakes that updates the 2016 one-year forecast; this map is intended to provide information to the public and to facilitate the development of induced seismicity forecasting models, methods, and data. The 2017 hazard model applies the same methodology and input logic tree as the 2016 forecast, but with an updated earthquake catalog. We also evaluate the 2016 seismic hazard forecast to improve future assessments. The 2016 forecast indicated high seismic hazard (greater than 1% probability of potentially damaging ground shaking in one-year) in five focus areas: Oklahoma-Kansas, the Raton Basin (Colorado/New Mexico border), north Texas, north Arkansas, and the New Madrid Seismic Zone. During 2016, several damaging induced earthquakes occurred in Oklahoma within the highest hazard region of the 2016 forecast; all of the 21 magnitude (M) ≥ 4 and three M ≥ 5 earthquakes occurred within the highest hazard area in the 2016 forecast. Outside the Oklahoma-Kansas focus area two earthquakes with M ≥ 4 occurred near Trinidad, Colorado (in the Raton Basin focus area), but no earthquakes with M ≥ 2.7 were observed in the north Texas or north Arkansas focus areas. Several observations of damaging ground shaking levels were also recorded in the highest hazard region of Oklahoma. The 2017 forecasted seismic rates are lower in regions of induced activity due to lower rates of earthquakes in 2016 compared to 2015, which may be related to decreased wastewater injection, caused by regulatory actions or by a decrease in unconventional oil and gas production. Nevertheless, the 2017 forecasted hazard is still significantly elevated in Oklahoma compared to the hazard calculated from seismicity before 2009.

Catchment-flowline network and selected model inputs for an enhanced and updated spatially referenced statistical assessment of dissolved-solids load sources and transport in streams of the Upper Colorado River Basin

Released March 08, 2017 00:00 EST

2017, Dataset

Susan G. Buto, Lawrence E. Spangler, Alan L. Flint, Lorraine E. Flint

This USGS data release consists of the synthetic stream network and associated catchments used to develop spatially referenced regressions on watershed attributes (SPARROW) model of dissolved-solids sources and transport in the Upper Colorado River Basin as well as geology and selected Basin Characterization Model (BCM) data used as input to the model.

The effects of forest cover on base flow of streams in the mountainous interior of Puerto Rico, 2010

Released March 07, 2017 15:45 EST

2017, Scientific Investigations Report 2016-5142

Jesús Rodriguez-Martínez , Marilyn Santiago

The U.S. Geological Survey, in cooperation with the Puerto Rico Department of Natural and Environmental Resources, completed a study to determine whether a relation exists between the extent of forest cover and the magnitude of base flow at two sets of paired drainage basins in the highlands of the municipalities of Adjuntas and Utuado within the mountainous interior of Puerto Rico. One set of paired basins includes the Río Guaónica and Río Tanamá, both tributaries of the Río Grande de Arecibo. The other set includes two smaller basins in the drainage basin of the Río Coabey, which is a tributary of the Río Tanamá. The paired basins in each set have similar rainfall patterns, geologic substrate, and aspect; the principal difference identified in the study is the extent of forest cover and related land uses such as the cultivation of shade and sun coffee. Data describing the hydrology, hydrogeology, and streamflow were used in the analysis. The principal objective of the study was to compare base flow per unit area among basins having different areal extents of forest cover and land uses such as shade coffee and sun coffee cultivation.

Within the mountainous interior of Puerto Rico, a substantial amount of the annual rainfall (45 to 39 percent in the Rio Guaónica and Rio Tanamá, respectively) can migrate to the subsurface and later emerge as base flow in streams. The magnitude of base flow within the two sets of paired basins varies seasonally. Minimum base flows occur during the annual dry season (generally from January to March), and maximum base flows occur during the wet season (generally from August to October). During the dry season or periods of below-normal rainfall, base flow is either the primary or the sole component of streamflow. Daily mean base flow ranged from 3.2 to 20.5 cubic feet per second (ft3 /s) at the Rio Guaónica Basin, and from 4.2 to 23.0 ft3 /s at the Rio Tanamá Basin. The daily mean base flows during 2010 ranged from 0.28 to 0.98 ft3 /s at Tributary 1 and from 0.22 to 0.58 ft3 /s at Tributary 2 of the Rio Coabey. The normalized daily base flow at the Río Guaónica and Río Tanamá Basin during 2010 ranged from 1.3 to 8.1 cubic feet per second per square mile (ft3 /s)/mi2 and from 1.1 to 6.1 (ft3 /s)/mi2 , respectively. The normalized daily base flow for the basins of Tributary 1 and Tributary 2 of Río Coabey during 2010 ranged from 1.0 to 3.6 (ft3 /s)/mi2 and from 1.5 to 3.9 (ft3 /s)/mi2 , respectively.

The normalized mean annual base flow is similar within the larger paired basins of Río Tanamá (2.74 [ft3 /s]/mi2 ) and Río Guaónica (3.15 [ft3 /s]/mi2 ). The mean annual base flow per unit area for both of these basins is about 79 percent of the mean annual streamflow. In the large paired basins, the proportion of Type I land use (forest patches, shade and mixed shade/sun coffee with associated cash crops) is substantially higher in Rio Guaónica Basin (81 percent) than in the Rio Tanamá Basin (59 percent), and the base flow per unit area is also higher. In the small paired basins of Rio Coabey, the proportion of Type I land use is much higher at Tributary 1 (52 percent) than at Tributary 2 (15 percent), but, in contrast to the large basins, the mean annual base flow per unit area is lower (2.22 and 2.62 [ft3 /s]/mi2 , respectively). There is no consistent relation between land use and normalized base flow between the two sets of paired basins in the study.

Vertical datum conversion process for the inland and coastal gage network located in the New England, Mid-Atlantic, and South Atlantic-Gulf hydrologic regions

Released March 07, 2017 09:30 EST

2017, Techniques and Methods 11-B8

Paul H. Rydlund, Jr., Michael L. Noll

Datum conversions from the National Geodetic Vertical Datum of 1929 to the North American Vertical Datum of 1988 among inland and coastal gages throughout the hydrologic regions of New England, the Mid-Atlantic, and the South Atlantic-Gulf have implications among river and storm surge forecasting, general commerce, and water-control operations. The process of data conversions may involve the application of a recovered National Geodetic Vertical Datum of 1929–North American Vertical Datum of 1988 offset, a simplistic datum transformation using VDatum or VERTCON software, or a survey, depending on a gaging network datum evaluation, anticipated uncertainties for data use among the cooperative water community, and methods used to derive the conversion. Datum transformations from National Geodetic Vertical Datum of 1929 to North American Vertical Datum of 1988 using VERTCON purport errors of ± 0.13 foot at the 95 percent confidence level among modeled points, claiming more consistency along the east coast. Survey methods involving differential and trigonometric leveling, along with observations using Global Navigation Satellite System technology, afford a variety of approaches to establish or perpetuate a datum during a survey. Uncertainties among leveling approaches are generally < 0.1 foot, and and Global Navigation Satellite System approaches may be categorized with uncertainties of ≤0.1 foot for a Level I quality category and ≥0.1 foot for Level II or III quality categories (defined by the U.S. Geological Survey) by observation and review of experienced practice. The conversion process is initiated with an evaluation of the inland and coastal gage network datum, beginning with altitude datum components and the history of those components queried through the U.S. Geological Survey Groundwater Site Inventory database. Subsequent edits to the Groundwater Site Inventory database may be required and a consensus reached among the U.S. Geological Survey Water Science Centers to identify the outstanding workload categorized as in-office datum transformations or offset applications versus out-of-office survey efforts. Datum conversions or datum establishment for the inland or coastal gaging network should meet datum uncertainty requirements among other Federal agencies. Datum uncertainty requirements are ±0.25 foot for U.S. Army Corps of Engineers water-control or construction projects and ±0.16 foot for Federal Emergency Management Agency field surveys and checkpoint surveys used for mapping. River level forecasts generally are defined as ± 0.10 foot among the National Oceanic and Atmospheric Administration–National Weather Service. Collaboration and communication among the cooperative water community is necessary during a datum conversion or datum change. Datum notification time-change requirements set by the National Oceanic and Atmospheric Administration–National Weather Service vary from 30 to 120 days, depending on datum conversion or datum-change case scenarios. Notification times associated with these case scenarios may be useful to the National Oceanic and Atmospheric Administration–National Weather Service and U.S. Army Corps of Engineers, because their daily operations are time sensitive, unlike the notification time change requirements of other entities that make up the cooperative water community. At the time of this writing, a future geopotential datum resulting from Gravity for the Redefinition of the American Vertical Datum is anticipated in 2022. A future version of VDatum and VERTCON is anticipated to provide a transformation among North American Vertical Datum of 1988 elevations to the new geopotential datum.

Isotopic data for Late Cretaceous intrusions and associated altered and mineralized rocks in the Big Belt Mountains, Montana

Released March 07, 2017 00:12 EST

2017, Data Series 1040

Edward A. du Bray, Daniel M. Unruh, Albert H. Hofstra

The quartz monzodiorite of Mount Edith and the concentrically zoned intrusive suite of Boulder Baldy constitute the principal Late Cretaceous igneous intrusions hosted by Mesoproterozoic sedimentary rocks of the Newland Formation in the Big Belt Mountains, Montana. These calc-alkaline plutonic masses are manifestations of subduction-related magmatism that prevailed along the western edge of North America during the Cretaceous. Radiogenic isotope data for neodymium, strontium, and lead indicate that the petrogenesis of the associated magmas involved a combination of (1) sources that were compositionally heterogeneous at the scale of the geographically restricted intrusive rocks in the Big Belt Mountains and (2) variable contamination by crustal assimilants also having diverse isotopic compositions. Altered and mineralized rocks temporally, spatially, and genetically related to these intrusions manifest at least two isotopically distinct mineralizing events, both of which involve major inputs from spatially associated Late Cretaceous igneous rocks. Alteration and mineralization of rock associated with the intrusive suite of Boulder Baldy requires a component characterized by significantly more radiogenic strontium than that characteristic of the associated igneous rocks. However, the source of such a component was not identified in the Big Belt Mountains. Similarly, altered and mineralized rocks associated with the quartz monzodiorite of Mount Edith include a component characterized by significantly more radiogenic strontium and lead, particularly as defined by 207Pb/204Pb values. The source of this component appears to be fluids that equilibrated with proximal Newland Formation rocks. Oxygen isotope data for rocks of the intrusive suite of Boulder Baldy are similar to those of subduction-related magmatism that include mantle-derived components; oxygen isotope data for altered and mineralized equivalents are slightly lighter.

Pushing precipitation to the extremes in distributed experiments: Recommendations for simulating wet and dry years

Released March 07, 2017 00:00 EST

2017, Global Change Biology

Alan K. Knapp, Meghan L. Avolio, Claus Beier, Charles J.W. Carroll, Scott L. Collins, Jeffrey S. Dukes, Lauchlan H. Fraser, Robert J. Griffin-Nolan, David L. Hoover, Anke Jentsch, Michael E. Loik, Richard P. Phillips, Alison K. Post, Osvaldo E. Sala, Ingrid J. Slette, Laura Yahdjian, Melinda D. Smith

Intensification of the global hydrological cycle, ranging from larger individual precipitation events to more extreme multiyear droughts, has the potential to cause widespread alterations in ecosystem structure and function. With evidence that the incidence of extreme precipitation years (defined statistically from historical precipitation records) is increasing, there is a clear need to identify ecosystems that are most vulnerable to these changes and understand why some ecosystems are more sensitive to extremes than others. To date, opportunistic studies of naturally occurring extreme precipitation years, combined with results from a relatively small number of experiments, have provided limited mechanistic understanding of differences in ecosystem sensitivity, suggesting that new approaches are needed. Coordinated distributed experiments (CDEs) arrayed across multiple ecosystem types and focused on water can enhance our understanding of differential ecosystem sensitivity to precipitation extremes, but there are many design challenges to overcome (e.g., cost, comparability, standardization). Here, we evaluate contemporary experimental approaches for manipulating precipitation under field conditions to inform the design of ‘Drought-Net’, a relatively low-cost CDE that simulates extreme precipitation years. A common method for imposing both dry and wet years is to alter each ambient precipitation event. We endorse this approach for imposing extreme precipitation years because it simultaneously alters other precipitation characteristics (i.e., event size) consistent with natural precipitation patterns. However, we do not advocate applying identical treatment levels at all sites – a common approach to standardization in CDEs. This is because precipitation variability varies >fivefold globally resulting in a wide range of ecosystem-specific thresholds for defining extreme precipitation years. For CDEs focused on precipitation extremes, treatments should be based on each site's past climatic characteristics. This approach, though not often used by ecologists, allows ecological responses to be directly compared across disparate ecosystems and climates, facilitating process-level understanding of ecosystem sensitivity to precipitation extremes.

An evaluation of inorganic toxicity reference values for use in assessing hazards to American robins (Turdus migratorius)

Released March 07, 2017 00:00 EST

2017, Integrated Environmental Assessment and Management (13) 352-359

W. Nelson Beyer, Bradley E. Sample

When performing screening-level and baseline risk assessments, assessors usually compare estimated exposures of wildlife receptor species with toxicity reference values (TRVs). We modeled the exposure of American robins (Turdus migratorius) to 10 elements (As, Cd, Cr, Cu, Hg, Mn, Pb, Se, Zn, and V) in spring and early summer, a time when earthworms are the preferred prey. We calculated soil benchmarks associated with possible toxic effects to these robins from 6 sets of published TRVs. Several of the resulting soil screening-level benchmarks were inconsistent with each other and less than soil background concentrations. Accordingly, we examined the derivations of the TRVs as a possible source of error. In the case of V, a particularly toxic chemical compound (ammonium vanadate) containing V, not normally present in soil, had been used to estimate a TRV. In the cases of Zn and Cu, use of uncertainty values of 10 in estimating TRVs led to implausibly low soil screening values. In the case of Pb, a TRV was calculated from studies demonstrating reductions in egg production in Japanese quail (Coturnix coturnix japonica) exposed to Pb concentrations well below than those causing toxic effects in other species of birds. The results on quail, which were replicated in additional trials, are probably not applicable to other, unrelated species, although we acknowledge that only a small fraction of all species of birds has been tested. These examples underscore the importance of understanding the derivation and relevance of TRVs before selecting them for use in screening or in ecological risk assessment.

Prediction and visualization of redox conditions in the groundwater of Central Valley, California

Released March 07, 2017 00:00 EST

2017, Journal of Hydrology (546) 341-356

Celia Z. Rosecrans, Bernard T. Nolan, JoAnn M. Gronberg

Regional-scale, three-dimensional continuous probability models, were constructed for aspects of redox conditions in the groundwater system of the Central Valley, California. These models yield grids depicting the probability that groundwater in a particular location will have dissolved oxygen (DO) concentrations less than selected threshold values representing anoxic groundwater conditions, or will have dissolved manganese (Mn) concentrations greater than selected threshold values representing secondary drinking water-quality contaminant levels (SMCL) and health-based screening levels (HBSL). The probability models were constrained by the alluvial boundary of the Central Valley to a depth of approximately 300 m. Probability distribution grids can be extracted from the 3-D models at any desired depth, and are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to anoxic conditions.

Models were constructed using a Boosted Regression Trees (BRT) machine learning technique that produces many trees as part of an additive model and has the ability to handle many variables, automatically incorporate interactions, and is resistant to collinearity. Machine learning methods for statistical prediction are becoming increasing popular in that they do not require assumptions associated with traditional hypothesis testing. Models were constructed using measured dissolved oxygen and manganese concentrations sampled from 2767 wells within the alluvial boundary of the Central Valley, and over 60 explanatory variables representing regional-scale soil properties, soil chemistry, land use, aquifer textures, and aquifer hydrologic properties. Models were trained on a USGS dataset of 932 wells, and evaluated on an independent hold-out dataset of 1835 wells from the California Division of Drinking Water. We used cross-validation to assess the predictive performance of models of varying complexity, as a basis for selecting final models. Trained models were applied to cross-validation testing data and a separate hold-out dataset to evaluate model predictive performance by emphasizing three model metrics of fit: Kappa; accuracy; and the area under the receiver operator characteristic curve (ROC). The final trained models were used for mapping predictions at discrete depths to a depth of 304.8 m. Trained DO and Mn models had accuracies of 86–100%, Kappa values of 0.69–0.99, and ROC values of 0.92–1.0. Model accuracies for cross-validation testing datasets were 82–95% and ROC values were 0.87–0.91, indicating good predictive performance. Kappas for the cross-validation testing dataset were 0.30–0.69, indicating fair to substantial agreement between testing observations and model predictions. Hold-out data were available for the manganese model only and indicated accuracies of 89–97%, ROC values of 0.73–0.75, and Kappa values of 0.06–0.30. The predictive performance of both the DO and Mn models was reasonable, considering all three of these fit metrics and the low percentages of low-DO and high-Mn events in the data.

Enhanced and updated spatially referenced statistical assessment of dissolved-solids load sources and transport in streams of the Upper Colorado River Basin

Released March 07, 2017 00:00 EST

2017, Scientific Investigations Report 2017-5009

Matthew P. Miller, Susan G. Buto, Patrick M. Lambert, Christine A. Rumsey

Approximately 6.4 million tons of dissolved solids are discharged from the Upper Colorado River Basin (UCRB) to the Lower Colorado River Basin each year. This results in substantial economic damages, and tens of millions of dollars are spent annually on salinity control projects designed to reduce salinity loads in surface waters of the UCRB. Dissolved solids in surface water and groundwater have been studied extensively over the past century, and these studies have contributed to a conceptual understanding of sources and transport of dissolved solids. This conceptual understanding was incorporated into a Spatially Referenced Regressions on Watershed Attributes (SPARROW) model to examine sources and transport of dissolved solids in the UCRB. The results of this model were published in 2009. The present report documents the methods and data used to develop an updated dissolved-solids SPARROW model for the UCRB, and incorporates data defining current basin attributes not available in the previous model, including delineation of irrigated lands by irrigation type (sprinkler or flood irrigation), and calibration data from additional monitoring sites.

Dissolved-solids loads estimated for 312 monitoring sites were used to calibrate the SPARROW model, which predicted loads for each of 10,789 stream reaches in the UCRB. The calibrated model provided a good fit to the calibration data as evidenced by R2 and yield R2 values of 0.96 and 0.73, respectively, and a root-mean-square error of 0.47. The model included seven geologic sources that have estimated dissolved-solids yields ranging from approximately 1 to 45 tons per square mile (tons/mi2). Yields generated from irrigated agricultural lands are substantially greater than those from geologic sources, with sprinkler irrigated lands generating an average of approximately 150 tons/mi2 and flood irrigated lands generating between 770 and 2,300 tons/mi2 depending on underlying lithology. The coefficients estimated for six landscape transport characteristics that influence the delivery of dissolved solids from sources to streams, are consistent with the process understanding of dissolved-solids loading to streams in the UCRB.

Dissolved-solids loads and the proportion of those loads among sources in the entire UCRB as well as in major tributaries in the basin are reported, as are loads generated from irrigated lands, rangelands, Bureau of Land Management (BLM) lands, and grazing allotments on BLM lands. Model-predicted loads also are compared with load estimates from 1957 and 1991 at selected locations in three divisions of the UCRB. At the basin scale, the model estimates that 32 percent of the dissolved-solids loads are from irrigated agricultural land sources that compose less than 2 percent of the land area in the UCRB. This estimate is less than previously reported estimates of 40 to 45 percent of basin-scale dissolved-solids loads from irrigated agricultural land sources. This discrepancy could be a result of the implementation of salinity control projects in the basin. Notably, results indicate that the conversion of flood irrigated agricultural lands to sprinkler irrigated agricultural lands is a likely process contributing to the temporal decrease in dissolved-solids loads from irrigated lands.

Interactions of landscape disturbances and climate change dictate ecological pattern and process: spatial modeling of wildfire, insect, and disease dynamics under future climates

Released March 07, 2017 00:00 EST

2016, Landscape Ecology

Rachel Loehman, Robert E. Keane, Lisa M. Holsinger, Zhiwei Wu


Interactions among disturbances, climate, and vegetation influence landscape patterns and ecosystem processes. Climate changes, exotic invasions, beetle outbreaks, altered fire regimes, and human activities may interact to produce landscapes that appear and function beyond historical analogs.


We used the mechanistic ecosystem-fire process model FireBGCv2 to model interactions of wildland fire, mountain pine beetle (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola) under current and future climates, across three diverse study areas.


We assessed changes in tree basal area as a measure of landscape response over a 300-year simulation period for the Crown of the Continent in north-central Montana, East Fork of the Bitterroot River in western Montana, and Yellowstone Central Plateau in western Wyoming, USA.


Interacting disturbances reduced overall basal area via increased tree mortality of host species. Wildfire decreased basal area more than beetles or rust, and disturbance interactions modeled under future climate significantly altered landscape basal area as compared with no-disturbance and current climate scenarios. Responses varied among landscapes depending on species composition, sensitivity to fire, and pathogen and beetle suitability and susceptibility.


Understanding disturbance interactions is critical for managing landscapes because forest responses to wildfires, pathogens, and beetle attacks may offset or exacerbate climate influences, with consequences for wildlife, carbon, and biodiversity.

Analysis of Neogene deformation between Beaver, Utah and Barstow, California: Suggestions for altering the extensional paradigm

Released March 07, 2017 00:00 EST

2013, Geological Society of America Special Papers (499) 1-67

R. Ernest Anderson, Sue Beard, Edward A. Mankinen, John W. Hillhouse

For more than two decades, the paradigm of large-magnitude (~250 km), northwest-directed (~N70°W) Neogene extensional lengthening between the Colorado Plateau and Sierra Nevada at the approximate latitude of Las Vegas has remained largely unchallenged, as has the notion that the strain integrates with coeval strains in adjacent regions and with plate-boundary strain. The paradigm depends on poorly constrained interconnectedness of extreme-case lengthening estimated at scattered localities within the region. Here we evaluate the soundness of the inferred strain interconnectedness over an area reaching 600 km southwest from Beaver, Utah, to Barstow, California, and conclude that lengthening is overestimated in most areas and, even if the estimates are valid, lengthening is not interconnected in a way that allows for published versions of province-wide summations.

We summarize Neogene strike slip in 13 areas distributed from central Utah to Lake Mead. In general, left-sense shear and associated structures define a broad zone of translation approximately parallel to the eastern boundary of the Basin and Range against the Colorado Plateau, a zone we refer to as the Hingeline shear zone. Areas of steep-axis rotation (ranging to 2500 km2) record N-S shortening rather than unevenly distributed lengthening. In most cases, the rotational shortening and extension-parallel folds and thrusts are coupled to, or absorb, strike slip, thus providing valuable insight into how the discontinuous strike-slip faults are simply parts of a broad zone of continuous strain. The discontinuous nature of strike slip and the complex mixture of extensional, contractional, and steep-axis rotational structures in the Hingeline shear zone are similar to those in the Walker Lane belt in the west part of the Basin and Range, and, together, the two record southward displacement of the central and northern Basin and Range relative to the adjacent Colorado Plateau. Understanding this province-scale coupling is critical to understanding major NS shortening and westerly tectonic escape in the Lake Mead area.

One north-elongate uplift in the Hingeline shear zone is a positive flower structure along a strike-slip fault, and we postulate that most other large uplifts are diapiric, resulting from extension-normal inflow of ductile substrate, rather than second-order isostatic responses to tectonic unloading. We also postulate that large steep-axis rotations, and some small ones as well, result from basal tractions imparted by gradients in southerly directed subjacent ductile flow rather than by shear coupling imparted by laterally variable elongation strains. The shortening strain recorded in the rotations and related structures probably matches or exceeds the magnitude of lengthening, even for the Lake Mead area where we do not question local large (~65 km) west-directed lengthening. We assess the results of extensive recent earth-science research in the Lake Mead area and conclude that previously published models of N-S convergence, westerly tectonic rafting, and N-S occlusion are valid and record unique tectonic escape accommodation for south-directed displacement of the Great Basin sector of the Basin and Range. Genetic ties between the south-directed displacement and plate-interaction forces are elusive, and we suggest the displacement results from body forces inherent in the Basin and Range.

Bathymetry of Clear Creek Reservoir, Chaffee County, Colorado, 2016

Released March 06, 2017 16:15 EST

2017, Scientific Investigations Map 3375

Michael S. Kohn, Paul J. Kinzel, Jacob S. Mohrmann

To better characterize the water supply capacity of Clear Creek Reservoir, Chaffee County, Colorado, the U.S. Geological Survey, in cooperation with the Pueblo Board of Water Works and Colorado Mountain College, carried out a bathymetry survey of Clear Creek Reservoir. A bathymetry map of the reservoir is presented here with the elevation-surface area and the elevation-volume relations. The bathymetry survey was carried out June 6–9, 2016, using a man-operated boat-mounted, multibeam echo sounder integrated with a Global Positioning System and a terrestrial survey using real-time kinematic Global Navigation Satellite Systems. The two collected datasets were merged and imported into geographic information system software. The equipment and methods used in this study allowed water-resource managers to maintain typical reservoir operations, eliminating the need to empty the reservoir to carry out the survey.

Assessment of continuous oil resources in the Wolfcamp shale of the Midland Basin, Permian Basin Province, Texas, 2016

Released March 06, 2017 13:00 EST

2017, Open-File Report 2017-1013

Stephanie B. Gaswirth

The U.S. Geological Survey completed a geology-based assessment of undiscovered, technically recoverable continuous petroleum resources in the Wolfcamp shale in the Midland Basin part of the Permian Basin Province of west Texas. This is the first U.S. Geological Survey evaluation of continuous resources in the Wolfcamp shale in the Midland Basin. Since the 1980s, the Wolfcamp shale in the Midland Basin has been part of the “Wolfberry” play. This play has traditionally been developed using vertical wells that are completed and stimulated in multiple productive stratigraphic intervals that include the Wolfcamp shale and overlying Spraberry Formation. Since the shift to horizontal wells targeting the organic-rich shale of the Wolfcamp, more than 3,000 horizontal wells have been drilled and completed in the Midland Basin Wolfcamp section. The U.S. Geological Survey assessed technically recoverable mean resources of 20 billion barrels of oil and 16 trillion cubic feet of associated gas in the Wolfcamp shale in the Midland Basin.

Groundwater quality for 75 domestic wells in Lycoming County, Pennsylvania, 2014

Released March 06, 2017 09:00 EST

2017, Scientific Investigations Report 2016-5143

Eliza L. Gross, Charles A. Cravotta

Groundwater is a major source of drinking water in Lycoming County and adjacent counties in north-central and northeastern Pennsylvania, which are largely forested and rural and are currently undergoing development for hydrocarbon gases. Water-quality data are needed for assessing the natural characteristics of the groundwater resource and the potential effects from energy and mineral extraction, timber harvesting, agriculture, sewage and septic systems, and other human influences.

This report, prepared in cooperation with Lycoming County, presents analytical data for groundwater samples from 75 domestic wells sampled throughout Lycoming County in June, July, and August 2014. The samples were collected using existing pumps and plumbing prior to any treatment and analyzed for physical and chemical characteristics, including nutrients, major ions, metals and trace elements, volatile organic compounds, gross-alpha particle and gross beta-particle activity, uranium, and dissolved gases, including methane and radon-222.

Results indicate groundwater quality generally met most drinking-water standards, but that some samples exceeded primary or secondary maximum contaminant levels (MCLs) for arsenic, iron, manganese, total dissolved solids (TDS), chloride, pH, bacteria, or radon-222. Arsenic concentrations were higher than the MCL of 10 micrograms per liter (µg/L) in 9 of the 75 (12 percent) well-water samples, with concentrations as high as 23.6 μg/L; arsenic concentrations were higher than the health advisory level (HAL) of 2 μg/L in 23 samples (31 percent). Total iron concentrations exceeded the secondary maximum contaminant level (SMCL) of 300 μg/L in 20 of the 75 samples. Total manganese concentrations exceeded the SMCL of 50 μg/L in 20 samples and the HAL of 300 μg/L in 2 of those samples. Three samples had chloride concentrations that exceeded the SMCL of 250 milligrams per liter (mg/L); two of those samples exceeded the SMCL of 500 mg/L for TDS. The pH ranged from 5.3 to 9.15 and did not meet the SMCL range of 6.5 to 8.5 in 22 samples, with 17 samples having a pH less than 6.5 and 8 samples having pH greater than 8.5. Generally, the samples that had elevated TDS, chloride, or arsenic concentrations had high pH.

Total coliform bacteria were detected in 39 of 75 samples (52 percent), with Escherichia coli detected in 10 of those 39 samples. Radon-222 activities ranged from non-detect to 7,420 picocuries per liter (pCi/L), with a median of 863 pCi/L, and exceeded the proposed drinking-water standard of 300 pCi/L in 50 (67 percent) of the 75 samples; radon-222 activities were higher than the alternative proposed standard of 4,000 pCi/L in 3 samples.

Water from 15 of 75 (20 percent) wells had concentrations of methane greater than the reporting level of 0.01 mg/L; detectable methane concentrations ranged from 0.04 to 16.8 mg/L. Two samples had methane concentrations (13.1 and 16.8 mg/L) exceeding the action level of 7 mg/L. Low levels of ethane (up to 0.12 mg/L) were present in the five samples with the highest methane concentrations (near or above 1 mg/L) that were analyzed for hydrocarbon compounds and isotopic composition. The isotopic composition of methane in four of these groundwater samples, from the Catskill and Lock Haven Formations and the Hamilton Group, have sample carbon isotopic ratio delta values (carbon-13/carbon-12) ranging from –42.36 to –36.08 parts per thousand (‰) and hydrogen isotopic ratio delta values (deuterium/protium) ranging from –212.0 to –188.4 ‰, which are consistent with the isotopic compositions reported for mud-gas logging samples from these geologic units and a thermogenic source of the methane. However, the isotopic composition and ratios of methane to ethane in a fifth sample indicate the methane in that sample may be of microbial origin that subsequently underwent oxidation. The fifth sample had the highest concentration of methane, 16.8 mg/L, with an carbon isotopic ratio delta values of -50.59 ‰ and a hydrogen isotopic ratio delta values of -209.7 ‰.

The six well-water samples with the highest methane concentrations also had among the highest pH values (8.25 to 9.15) and elevated concentrations of sodium, lithium, boron, fluoride, arsenic, and bromide. Relatively elevated concentrations of some other constituents, such as barium, strontium, and chloride, commonly were present in, but not limited to, those well-water samples with elevated methane.

Three of the six groundwater samples with the highest methane concentrations had chloride/bromide ratios that indicate mixing with a small amount of brine (0.02 percent or less) similar in composition to those reported at undetermined depth below the freshwater aquifer and for gas and oil well brines in Pennsylvania. The sample with the highest methane concentration and most other samples with low methane concentrations (less than about 1 mg/L) have chloride/bromide ratios that indicate predominantly anthropogenic sources of chloride, such as road-deicing salt, septic systems, and (or) animal waste. Brines that are naturally present may originate from deeper parts of the aquifer system, while anthropogenic sources are more likely to affect shallow groundwater because they occur on or near the land-surface.

The spatial distribution of groundwater compositions generally indicate that (1) uplands along the western border of Lycoming County usually have dilute, slightly acidic oxygenated, calcium-bicarbonate type waters; (2) intermediate altitudes or areas of carbonate bedrock usually have water of near neutral pH, with highest amounts of hardness (calcium and magnesium); (3) stream valleys, low elevations where groundwater may be discharging, and deep wells in uplands usually have water with pH values greater than 8 and highest arsenic, sodium, lithium, bromide concentrations. Geochemical modeling indicated that for samples with elevated pH, sodium, lithium, bromide, and alkalinity, the water chemistry could have resulted by dissolution of calcite (calcium carbonate) combined with cation-exchange and mixing with a small amount of brine. Through cation-exchange reactions between water and bedrock, which are equivalent to processes in a water softener, calcium ions released by calcite dissolution are exchanged for sodium ions on clay minerals. Thus, the assessment of groundwater quality in Lycoming County indicates groundwater is generally of good quality, but various parts of Lycoming County can have groundwater with low to moderate concentrations of methane and other constituents that appear in naturally present brine and produced waters from gas and oil wells at high concentrations."

Taxonomic revision of the South American catfish genus Ageneiosus (Siluriformes: Auchenipteridae) with the description of four new species

Released March 06, 2017 00:00 EST

2017, Journal of Fish Biology

Frank R.V. Ribeiro, Lúcia H. Rapp Py-Daniel, Stephen J. Walsh

The catfish genus Ageneiosus in the exclusively Neotropical family Auchenipteridae is revised. Species of Ageneiosus are widely distributed in all major South American continental drainages except the São Francisco River basin and small rivers along the Brazilian east coast. The taxonomic revision was based on examination of available type specimens, additional museum material and comparisons of original descriptions. A suite of morphometric, meristic and qualitative characters of internal and external anatomy were used to diagnose valid species and determine synonyms. Thirteen valid species are recognized in the genus Ageneiosus, some of which are widely distributed across South America. Ageneiosus pardalis is the only trans-Andean species in the genus. Ageneiosus polystictus and Ageneiosus uranophthalmus are more widely distributed than previously reported. Ageneiosus marmoratus is a junior synonym of Ageneiosus inermis. Ageneiosus dentatus is a valid species and its name is removed from the synonymy of Ageneiosus ucayalensis. Four new species are described: Ageneiosus akamai, Ageneiosus apiaka, Ageneiosus intrusus and Ageneiosus lineatus, all from the Amazon River basin. A dichotomous key for all 13 valid species of Ageneiosus species is provided.

Cyanide poisoning of a Cooper’s hawk (Accipiter cooperii)

Released March 06, 2017 00:00 EST

2017, Journal of Veterinary Diagnostic Investigation (29) 258-260

J Christian Franson

A Cooper’s hawk (Accipiter cooperii) was found dead in a ditch leading from a heap leach pad at a gold mine in Nevada. Observations at autopsy included an absence of external lesions, traces of subcutaneous and coronary fat, no food in the upper gastrointestinal tract, and no lesions in the viscera. Cyanide concentrations (µg/g ww) were 5.04 in blood, 3.88 in liver, and 1.79 in brain. No bacteria or viruses were isolated from tissues, and brain cholinesterase activity was within the normal range for a Cooper’s hawk.

Geomyces and Pseudogymnoascus: Emergence of a primary pathogen, the causative agent of bat white-nose syndrome: Chapter 28

Released March 06, 2017 00:00 EST

2017, Book chapter, The fungal community: Its organization and role in the ecosystem

Michelle L. Verant, Andrew M. Minnis, Daniel L. Lindner, David Blehert

Geomyces and Pseudogymnoascus (Fungi, Ascomycota, Leotiomycetes, aff. Thelebolales) are closely related groups of globally occurring soil-associated fungi. Recently, these genera of fungi have received attention because a newly identified species, Pseudogymnoascus (initially classified as Geomyces) destructans, was discovered in association with significant and unusual mortality of hibernating bats in North America (Blehert et al. 2009; Gargas et al. 2009; Minnis and Linder 2013). This emergent disease called bat white-nose syndrome (WNS), has since caused drastic declines in populations of hibernating bats in the United States and Canada (Turner, Reeder, and Coleman 2011; Thogmartin et al. 2012) and threatens some species with regional extinction (Frick et al. 2010; Langwig et al. 2012; Thogmartin et al. 2013). As primary predators of insects and keystone species for cave ecosystems, the loss of bats due to WNS has important economic and ecological implications.

The effects of fipronil and the photodegradation product fipronil desulfinyl on growth and gene expression in juvenile blue crabs, Callinectes sapidus, at different salinities

Released March 06, 2017 00:00 EST

2017, Aquatic Toxicology (186) 96-104

Andrew D. Goff, Parichehr Saranjampour, Lauren M. Ryan, Michelle Hladik, Joseph A. Covi, Kevin L. Armbrust, Susanne M. Brander

Endocrine disrupting compounds (EDCs) are now widely established to be present in the environment at concentrations capable of affecting wild organisms. Although many studies have been conducted in fish, less is known about effects in invertebrates such as decapod crustaceans. Decapods are exposed to low concentrations of EDCs that may cause infertility, decreased growth, and developmental abnormalities. The objective herein was to evaluate effects of fipronil and its photodegradation product fipronil desulfinyl. Fipronil desulfinyl was detected in the eggs of the decapod Callinectes sapidus sampled off the coast of South Carolina. As such, to examine specific effects on C. sapidus exposed in early life, we exposed laboratory-reared juveniles to fipronil and fipronil desulfinyl for 96 hours at three nominal concentrations (0.01, 0.1, 0.5 μg/L) and two different salinities (10, 30 ppt). The size of individual crabs (weight, carapace width) and the expression of several genes critical to growth and reproduction were evaluated. Exposure to fipronil and fipronil desulfinyl resulted in significant size increases in all treatments compared to controls. Levels of expression for vitellogenin (Vtg), an egg yolk precursor, and the ecdysone receptor (EcR), which binds to ecdysteroids that control molting, were inversely correlated with increasing fipronil and fipronil desulfinyl concentrations. Effects on overall growth and on the expression of EcR and Vtg differ depending on the exposure salinity. The solubility of fipronil is demonstrated to decrease considerably at higher salinities. This suggests that fipronil and its photodegradation products may be more bioavailable to benthic organisms as salinity increases, as more chemical would partition to tissues. Our findings suggest that endocrine disruption is occurring through alterations to gene expression in C. sapidus populations exposed to environmental levels of fipronil, and that effects may be dependent upon the salinity at which exposure occurs.

Detecting spatial ontogenetic niche shifts in complex dendritic ecological networks

Released March 06, 2017 00:00 EST

2017, Ecosphere (8)

William R. Fields, Evan Grant, Winsor H. Lowe

Ontogenetic niche shifts (ONS) are important drivers of population and community dynamics, but they can be difficult to identify for species with prolonged larval or juvenile stages, or for species that inhabit continuous habitats. Most studies of ONS focus on single transitions among discrete habitat patches at local scales. However, for species with long larval or juvenile periods, affinity for particular locations within connected habitat networks may differ among cohorts. The resulting spatial patterns of distribution can result from a combination of landscape-scale habitat structure, position of a habitat patch within a network, and local habitat characteristics—all of which may interact and change as individuals grow. We estimated such spatial ONS for spring salamanders (Gyrinophilus porphyriticus), which have a larval period that can last 4 years or more. Using mixture models to identify larval cohorts from size frequency data, we fit occupancy models for each age class using two measures of the branching structure of stream networks and three measures of stream network position. Larval salamander cohorts showed different preferences for the position of a site within the stream network, and the strength of these responses depended on the basin-wide spatial structure of the stream network. The isolation of a site had a stronger effect on occupancy in watersheds with more isolated headwater streams, while the catchment area, which is associated with gradients in stream habitat, had a stronger effect on occupancy in watersheds with more paired headwater streams. Our results show that considering the spatial structure of habitat networks can provide new insights on ONS in long-lived species.

Long Valley Caldera-Mammoth Mountain unrest: The knowns and unknowns

Released March 06, 2017 00:00 EST

2017, Elements (13) 8-9

David P. Hill

This perspective is based largely on my study of the Long Valley Caldera (California, USA) over the past 40 years. Here, I’ll examine the “knowns” and the “known unknowns” of the complex tectonic–magmatic system of the Long Valley Caldera volcanic complex. I will also offer a few brief thoughts on the “unknown unknowns” of this system.

Extreme oceanographic forcing and coastal response due to the 2015–2016 El Niño

Released March 06, 2017 00:00 EST

2017, Nature Communications (8)

Patrick Barnard, Daniel J. Hoover, David M. Hubbard, Alexander Snyder, Bonnie C. Ludka, Jonathan Allan, George M. Kaminsky, Ruggiero Peter, Timu W. Gallien, Laura Gabel, Diana McCandless, Heather M. Weiner, Nicholas Cohn, Dylan L. Anderson, Katherine A. Serafin

The El Niño-Southern Oscillation is the dominant mode of interannual climate variability across the Pacific Ocean basin, with influence on the global climate. The two end members of the cycle, El Niño and La Niña, force anomalous oceanographic conditions and coastal response along the Pacific margin, exposing many heavily populated regions to increased coastal flooding and erosion hazards. However, a quantitative record of coastal impacts is spatially limited and temporally restricted to only the most recent events. Here we report on the oceanographic forcing and coastal response of the 2015–2016 El Niño, one of the strongest of the last 145 years. We show that winter wave energy equalled or exceeded measured historical maxima across the US West Coast, corresponding to anomalously large beach erosion across the region. Shorelines in many areas retreated beyond previously measured landward extremes, particularly along the sediment-starved California coast.

The California stream quality assessment

Released March 06, 2017 00:00 EST

2017, Fact Sheet 2017-3014

Peter C. Van Metre, Amanda L. Egler, Jason T. May

In 2017, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project is assessing stream quality in coastal California, United States. The USGS California Stream Quality Assessment (CSQA) will sample streams over most of the Central California Foothills and Coastal Mountains ecoregion (modified from Griffith and others, 2016), where rapid urban growth and intensive agriculture in the larger river valleys are raising concerns that stream health is being degraded. Findings will provide the public and policy-makers with information regarding which human and natural factors are the most critical in affecting stream quality and, thus, provide insights about possible approaches to protect the health of streams in the region.

Landsat eyes help guard the world's forests

Released March 03, 2017 16:45 EST

2017, Fact Sheet 2017-3018

Jon Campbell


The Landsat program is a joint effort between the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA), but the partner agencies have distinct roles. NASA develops remote-sensing instruments and spacecraft, launches satellites, and validates their performance in orbit. The USGS owns and operates Landsat satellites in space and manages their data transmissions, including ground reception, archiving, product generation, and public distribution. In 2008, with support from the U.S. Department of the Interior, the USGS made its Landsat data free to anyone in the world.

The current satellites in the Landsat program, Landsat 7 (launched in 1999) and Landsat 8 (launched in 2013), provide complete coverage of the Earth every eight days. A Landsat 9 satellite is scheduled for launch in late 2020.

Volcanic ash supports a diverse bacterial community in a marine mesocosm

Released March 03, 2017 00:00 EST

2017, Geobiology 1-11

Verena Witt, Paul M Ayris, David Damby, Corrado Cimarelli, Ulrich Kueppers, Donald B Dingwell, Gert Wörheide

Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems. Following heavy ash deposition, mass mortality of reef biota is expected, but little is known about the recovery of post-burial reef ecosystems. Reef regeneration depends partly upon the capacity of the ash deposit to be colonised by waterborne bacterial communities and may be influenced to an unknown extent by the physiochemical properties of the ash substrate itself. To determine the potential for volcanic ash to support pioneer bacterial colonisation, we exposed five well-characterised volcanic and coral reef substrates to a marine aquarium under low light conditions for 3 months: volcanic ash, synthetic volcanic glass, carbonate reef sand, calcite sand and quartz sand. Multivariate statistical analysis of Automated Ribosomal Intergenic Spacer Analysis (ARISA) fingerprinting data demonstrates clear segregation of volcanic substrates from the quartz and coral reef substrates over 3 months of bacterial colonisation. Overall bacterial diversity showed shared and substrate-specific bacterial communities; however, the volcanic ash substrate supported the most diverse bacterial community. These data suggest a significant influence of substrate properties (composition, granulometry and colour) on bacterial settlement. Our findings provide first insights into physicochemical controls on pioneer bacterial colonisation of volcanic ash and highlight the potential for volcanic ash deposits to support bacterial diversity in the aftermath of reef burial, on timescales that could permit cascading effects on larval settlement.

Pyrogenic carbon distribution in mineral topsoils of the northeastern United States

Released March 03, 2017 00:00 EST

2017, Geoderma (296) 69-78

Verena Jauss, Patrick J. Sullivan, Jonathan Sanderman, David Smith, Johannes Lehmann

Due to its slow turnover rates in soil, pyrogenic carbon (PyC) is considered an important C pool and relevant to climate change processes. Therefore, the amounts of soil PyC were compared to environmental covariates over an area of 327,757 km2 in the northeastern United States in order to understand the controls on PyC distribution over large areas. Topsoil (defined as the soil A horizon, after removal of any organic horizons) samples were collected at 165 field sites in a generalised random tessellation stratified design that corresponded to approximately 1 site per 1600 km2 and PyC was estimated from diffuse reflectance mid-infrared spectroscopy measurements using a partial least-squares regression analysis in conjunction with a large database of PyC measurements based on a solid-state 13C nuclear magnetic resonance spectroscopy technique. Three spatial models were applied to the data in order to relate critical environmental covariates to the changes in spatial density of PyC over the landscape. Regional mean density estimates of PyC were 11.0 g kg− 1 (0.84 Gg km− 2) for Ordinary Kriging, 25.8 g kg− 1(12.2 Gg km− 2) for Multivariate Linear Regression, and 26.1 g kg− 1 (12.4 Gg km− 2) for Bayesian Regression Kriging. Akaike Information Criterion (AIC) indicated that the Multivariate Linear Regression model performed best (AIC = 842.6; n = 165) compared to Ordinary Kriging (AIC = 982.4) and Bayesian Regression Kriging (AIC = 979.2). Soil PyC concentrations correlated well with total soil sulphur (P < 0.001; n = 165), plant tissue lignin (P = 0.003), and drainage class (P = 0.008). This suggests the opportunity of including related environmental parameters in the spatial assessment of PyC in soils. Better estimates of the contribution of PyC to the global carbon cycle will thus also require more accurate assessments of these covariates.

Pre-mining trace element and radiation exposure to biota from a breccia pipe uranium mine in the Grand Canyon (Arizona, USA) watershed

Released March 03, 2017 00:00 EST

2017, Environmental Monitoring and Assessment (189)

Jo E. Hinck, Danielle Cleveland, William G. Brumbaugh, Greg Linder, Julia S. Lankton

The risks to wildlife and humans from uranium (U) mining in the Grand Canyon watershed are largely unknown. In addition to U, other co-occurring ore constituents contribute to risks to biological receptors depending on their toxicological profiles. This study characterizes the pre-mining concentrations of total arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), thallium (Tl), U, and zinc (Zn); radiation levels; and histopathology in biota (vegetation, invertebrates, amphibians, birds, and mammals) at the Canyon Mine. Gross alpha levels were below the reporting limit (4 pCi/g) in all samples, and gross beta levels were indicative of background in vegetation (<10–17 pCi/g) and rodents (<10–43.5 pCi/g). Concentrations of U, Tl, Pb, Ni, Cu, and As in vegetation downwind from the mine were likely the result of aeolian transport. Chemical concentrations in rodents and terrestrial invertebrates indicate that surface disturbance during mine construction has not resulted in statistically significant spatial differences in fauna concentrations adjacent to the mine. Chemical concentrations in egg contents and nestlings of non-aquatic birds were less than method quantification limits or did not exceed toxicity thresholds. Bioaccumulation of As, Pb, Se, Tl, and U was evident in Western spadefoot (Spea multiplicata) tadpoles from the mine containment pond; concentrations of As (28.9–31.4 μg/g) and Se (5.81–7.20 μg/g) exceeded toxicity values and were significantly greater than in tadpoles from a nearby water source. Continued evaluation of As and Se in biota inhabiting and forging in the mine containment pond is warranted as mining progresses.

A physics-based earthquake simulator and its application to seismic hazard assessment in Calabria (Southern Italy) region

Released March 03, 2017 00:00 EST

2017, Acta Geophysica

Rodolfo Console, Anna Nardi, Roberto Carluccio, Maura Murru, Giuseppe Falcone, Thomas E. Parsons

The use of a newly developed earthquake simulator has allowed the production of catalogs lasting 100 kyr and containing more than 100,000 events of magnitudes ≥4.5. The model of the fault system upon which we applied the simulator code was obtained from the DISS 3.2.0 database, selecting all the faults that are recognized on the Calabria region, for a total of 22 fault segments. The application of our simulation algorithm provides typical features in time, space and magnitude behavior of the seismicity, which can be compared with those of the real observations. The results of the physics-based simulator algorithm were compared with those obtained by an alternative method using a slip-rate balanced technique. Finally, as an example of a possible use of synthetic catalogs, an attenuation law has been applied to all the events reported in the synthetic catalog for the production of maps showing the exceedance probability of given values of PGA on the territory under investigation.

Geospatial analysis identifies critical mineral-resource potential in Alaska

Released March 03, 2017 00:00 EST

2017, Fact Sheet 2017-3012

Susan Karl, Keith Labay

Katherine Jacques, Claire Landowski, editor(s)

Alaska consists of more than 663,000 square miles (1,717,000 square kilometers) of land—more than a sixth of the total area of the United States—and large tracts of it have not been systematically studied or sampled for mineral-resource potential. Many regions of the State are known to have significant mineral-resource potential, and there are currently six operating mines in the State along with numerous active mineral exploration projects. The U.S. Geological Survey and the Alaska Division of Geological & Geophysical Surveys have developed a new geospatial tool that integrates and analyzes publicly available databases of geologic information and estimates the mineral-resource potential for critical minerals, which was recently used to evaluate Alaska. The results of the analyses highlight areas that have known mineral deposits and also reveal areas that were not previously considered to be prospective for these deposit types. These results will inform land management decisions by Federal, State, and private landholders, and will also help guide future exploration activities and scientific investigations in Alaska.

Bedrock geologic map of the northern Alaska Peninsula area, southwestern Alaska

Released March 03, 2017 00:00 EST

2017, Scientific Investigations Map 2942

The northern Alaska Peninsula is a region of transition from the classic magmatic arc geology of the Alaska Peninsula to a Proterozoic and early Paleozoic carbonate platform and then to the poorly understood, tectonically complex sedimentary basins of southwestern Alaska. Physiographically, the region ranges from the high glaciated mountains of the Alaska-Aleutian Range to the coastal lowlands of Cook Inlet on the east and Bristol Bay on the southwest. The lower Ahklun Mountains and finger lakes on the west side of the map area show strong effects from glaciation. Structurally, a number of major faults cut the map area. Most important of these are the Bruin Bay Fault that parallels the coast of Cook Inlet, the Lake Clark Fault that cuts diagonally northeast to southwest across the eastern part of the map area, and the presently active Holitna Fault to the northwest that cuts surficial deposits.

Distinctive rock packages assigned to three provinces are overlain by younger sedimentary rocks and intruded by widely dispersed latest Cretaceous and (or) early Tertiary granitic rocks. Much of the east half of the map area lies in the Alaska-Aleutian Range province; the Jurassic to Tertiary Alaska-Aleutian Range batholith and derivative Jurassic sedimentary rocks form the core of this province, which is intruded and overlain by the Aleutian magmatic arc. The Lime Hills province, the carbonate platform, occurs in the north-central part of the map area. The Paleozoic and Mesozoic Ahklun Mountains province in the western part of the map area includes abundant chert, argillite, and graywacke and lesser limestone, basalt, and tectonic mélange. The Kuskokwim Group, an Upper Cretaceous turbidite sequence, is extensively exposed and bounds all three provinces in the west-central part of the map area.

Regional patterns of Mesozoic-Cenozoic magmatism in western Alaska revealed by new U-Pb and 40Ar/39Ar ages: Chapter D in Studies by the U.S. Geological Survey in Alaska, vol. 15

Released March 02, 2017 00:00 EST

2017, Professional Paper 1814-D

Dwight C. Bradley, Marti L. Miller, Richard M. Friedman, Paul W. Layer, Heather A. Bleick, James V. Jones, III, Steven E. Box, Susan M. Karl, Nora B. Shew, Timothy S. White, Alison B. Till, Julie A. Dumoulin, Thomas K. Bundtzen, Paul B. O'Sullivan, Thomas D. Ullrich

In support of regional geologic framework studies, we obtained 50 new argon-40/argon-39 (40Ar/39Ar) ages and 33 new uranium-lead (U-Pb) ages from igneous rocks of southwestern Alaska. Most of the samples are from the Sleetmute and Taylor Mountains quadrangles; smaller collections or individual samples are from the Bethel, Candle, Dillingham, Goodnews Bay, Holy Cross, Iditarod, Kantishna River, Lake Clark, Lime Hills, McGrath, Medfra, Talkeetna, and Tanana quadrangles.

A U-Pb zircon age of 317.7±0.6 million years (Ma) reveals the presence of Pennsylvanian intermediate igneous (probably volcanic) rocks in the Tikchik terrane, Bethel quadrangle. A U-Pb zircon age of 229.5±0.2 Ma from gabbro intruding the Rampart Group of the Angayucham-Tozitna terrane, Tanana quadrangle, confirms and tightens a previously cited Triassic age for this intrusive suite. A fresh mafic dike in Goodnews Bay quadrangle yielded a 40Ar/39Ar whole rock age of 155.0±1.9 Ma; this establishes a Jurassic or older age for the previously unconstrained (Paleozoic? to Mesozoic?) sandstone unit that it intrudes. A thick felsic tuff in the Gemuk Group in Taylor Mountains quadrangle yielded a U-Pb zircon age of 153.0±2.0 Ma, extending the age of magmatism in this part of the Togiak terrane back into the Late Jurassic. We report three new U-Pb zircon ages between 120 and 110 Ma—112.0±0.9 Ma from syenite in the Candle quadrangle, 114.9±0.3 Ma from orthogneiss assigned to the Ruby terrane in Iditarod quadrangle, and 116.6±0.1 Ma from a gabbro of the Dishna River mafic-ultramafic complex in Iditarod quadrangle. The latter result requires a substantial age revision, from Triassic to Cretaceous, for at least some rocks that have been mapped as the Dishna River mafic-ultramafic complex. A tuff in the Upper Cretaceous Kuskokwim Group yielded a U-Pb zircon (sensitive high-resolution ion microprobe, SHRIMP) age of 88.3±1.0 Ma; we speculate that the eruptive source was an arc along the trend of the Pebble porphyry copper deposit along the Gulf of Alaska continental margin. More than half of the new ages fall between 75 and 65 Ma, confirming the existence, based on conventional potassium-argon (K-Ar) ages, of a 70-Ma igneous flare-up across southwestern Alaska. Our new ages hint that during this pulse, the locus of magmatism shifted toward the Gulf of Alaska, that is, toward a more outboard position. This shift is consistent with the hypothesis that magmatism was the product of rollback of a subducted slab, which at that time would have been the Resurrection Plate. Intrusive rocks in the Taylor Mountains and Sleetmute quadrangles in the age range of 63 to 59 Ma were emplaced shortly before the onset of ridge subduction as dated by near-trench plutons in the adjacent part of the Chugach accretionary complex. Southwestern Alaska at this time would have been positioned above a very young subducted slab belonging to the Resurrection Plate; magmas, in this scenario, were generated near the edge of the slab window related to ridge subduction. A 56.3±0.2 Ma granite in Taylor Mountains quadrangle and a 54.7±0.7 Ma ashfall tuff in McGrath quadrangle were likely emplaced above the Resurrection-Kula slab window, which by this time is inferred to have entered the region. Another ashfall tuff in McGrath quadrangle, at 42.8±0.5 Ma, likely belongs to the Meshik Arc, the product of renewed subduction after inferred passage of the slab window. A 49.0±0.3-Ma rhyolite in Taylor Mountains quadrangle is about the age of the transition from slab window to renewed subduction. Two plutons in the western Alaska Range, at 31.8±0.4 and 30.9±0.6 Ma, belong to a suite of gabbro to peralkaline granite of unknown origin. Finally, a 4.6±0.1-Ma basalt from a flow in Taylor Mountains quadrangle belongs to the Neogene basaltic province of western Alaska. These rocks were erupted in a distal retroarc setting; the cause of magmatism is unknown. 

Water resources of the Southern Hills regional aquifer system, southeastern Louisiana

Released March 01, 2017 16:45 EST

2017, Fact Sheet 2017-3010

Vincent E. White

Information concerning the availability, use, and quality of groundwater in the 10 parishes overlying the Southern Hills regional aquifer system of Louisiana (fig. 1) is critical for water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, residents, and others for stewardship of this vital resource. Information on the availability, past and current use, use trends, and water quality from groundwater sources in these parishes is presented. Previously published reports (see References Cited section) and data stored in the U.S. Geological Survey’s National Water Information System (U.S. Geological Survey, 2017) are the primary sources of the information presented here.

Land-use change and managed aquifer recharge effects on the hydrogeochemistry of two contrasting atoll island aquifers, Roi-Namur Island, Republic of the Marshall Islands

Released March 01, 2017 00:00 EST

2017, Applied Geochemistry (80) 58-71

Mehrdad Hejazian, Jason Gurdak, Peter Swarzenski, Kingsley Odigie, Curt Storlazzi

Freshwater resources on low-lying atoll islands are highly vulnerable to climate change and sea-level rise. In addition to rainwater catchment, groundwater in the freshwater lens is a critically important water resource on many atoll islands, especially during drought. Although many atolls have high annual rainfall rates, dense natural vegetation and high evapotranspiration rates can limit recharge to the freshwater lens. Here we evaluate the effects of land-use/land-cover change and managed aquifer recharge on the hydrogeochemistry and supply of groundwater on Roi-Namur Island, Republic of the Marshall Islands. Roi-Namur is an artificially conjoined island that has similar hydrogeology on the Roi and Namur lobes, but has contrasting land-use/land-cover and managed aquifer recharge only on Roi. Vegetation removal and managed aquifer recharge operations have resulted in an estimated 8.6 x 105 m3 of potable groundwater in the freshwater lens on Roi, compared to only 1.6 x 104 m3 on Namur. We use groundwater samples from a suite of 33 vertically nested monitoring wells, statistical testing, and geochemical modeling using PHREEQC to show that the differences in land-use/land-cover and managed aquifer recharge on Roi and Namur have a statistically significant effect on several groundwater-quality parameters and the controlling geochemical processes. Results also indicate a seven-fold reduction in the dissolution of carbonate rock in the freshwater lens and overlying vadose zone of Roi compared to Namur. Mixing of seawater and the freshwater lens is a more dominant hydrogeochemical process on Roi because of the greater recharge and flushing of the aquifer with freshwater as compared to Namur. In contrast, equilibrium processes and dissolution-precipitation non-equilibrium reactions are more dominant on Namur because of the longer residence times relative to the rate of geochemical reactions. Findings from Roi-Namur Island support selective land-use/land-cover change and managed aquifer recharge as a promising management approach for communities on other low-lying atoll islands to increase the resilience of their groundwater supplies and help them adapt to future climate change related stresses.

Bathymetry and backscatter intensity of the sea floor of the Historic Area Remediation Site in 1996, 1998, and 2000

Released March 01, 2017 00:00 EST

2017, Dataset

Bradford Butman, William W. Danforth, John E. Hughes Clarke, Richard Signell

Surveys of the bathymetry and backscatter intensity of the sea floor of the Historic Area Remediation Site (HARS), offshore of New York and New Jersey, were carried out in 1996, 1998, and 2000 using a Simrad EM1000 multibeam echosounder mounted on the Canadian Coast Guard ship Frederick G. Creed. The objective of the multiple echosounder surveys was to map the bathymetry and surficial sediments over time as dredged material was placed in the HARS to remediate contaminated sediments. Maps derived from the multibeam surveys show sea-floor bathymetry, shaded-relief bathymetry, and backscatter intensity (a measure of sea-floor texture and roughness) at a spatial resolution of three meters. The area was mapped by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers and with support from the Canadian Hydrographic Service and the University of New Brunswick.

Digital seafloor images and sediment grain size from the mouth of the Columbia River, Oregon and Washington, 2014

Released March 01, 2017 00:00 EST

2017, Dataset

Guy R. Gelfenbaum, Emily Carlson, Andrew Stevens, David M. Rubin

Geo-referenced digital imagery of in-situ seafloor sediments in the mouth of the Columbia River was collected and analyzed to determine median grain size of the surface sediments. Digital imagery of the seafloor was collected with a “flying eyeball” (Rubin and others, 2007) from the R/V Parke Snavely from September 11 to September 13, 2014 (USGS Field Activity 2014-642-FA). The flying eyeball consists of a standard definition plumbing inspection video camera and LED light ring inserted in a 50 kg wrecking ball. The video camera has a resolution of 480 by 720 pixels with a resolution of 0.009 mm/pixel when the target is flush against the exterior surface of the lens. Sample locations were chosen to allow for the observation of spatial variability of grain size over the length of many large bedforms. The bedforms were identified from a bathymetric survey performed in a previous field effort in 2013 (Gelfenbaum and others, 2015). During survey operations, the flying eyeball was repeatedly lowered to the seafloor with a winch along the transect. The winch was equipped with a conducting cable that transmitted the video signal from the camera to the research vessel in real time where it was recorded with a Sony DV recorder. Positioning of the vessel was determined with an Applanix PosMV and integrated with the digital video recording at 1-Hz intervals using Red Hen Systems (RHS) VMS200 hardware, which encodes the position information on the audio channel of the video tape. In addition to the imagery, surface sediment was collected using a small Ponar, or "grab", sampler at 12 locations throughout the study area. The physical samples were emptied into a tray on the deck of the vessel and observed with the flying eyeball. Approximately 50 g of sediment from each sample was retained and later processed in the lab using a Beckman Coulter laser diffraction analyzer to determine grain-size distributions, which can be accessed on the "child item" to this data release: Sediment grain size and digital image calibration parameters from the mouth of the Columbia River, Oregon and Washington, 2014.

Still images were extracted from the videos using RHS IsWhere software, which embeds the images with the positioning information. Images were extracted from the video when the target substrate was flush against the exterior surface of the lens and the LED lights effectively illuminated the sediments. This process was performed for both the in-situ and sediment grab sample video types. The in-situ images are avaialble in the folder "" on this page, the sediment grab sample images are accessible through the child page in the folder titled "".

The size of sediment in the still images was determined using techniques described in Rubin (2004).  An auto-correlation was calculated for each image and a calibration equation relating the auto-correlation coefficient and median sediment diameter (D50) was developed using grain-size distributions derived from the laboratory analyzed grab samples. The calibration equation was used to assign D50 values to the images of the in-situ sediments which do not have a corresponding grab sample (Rubin, 2004; Buscumbe and Masselink, 2008; Barnard and others, 2007). The data used to develop the calibration as well as the resulting equation used to determine the D50 of each in-situ image can be found on the child item page of this data release.

This portion of the data release includes still images ( collected in the mouth of the Columbia River, a table that includes the image locations and derived sediment D50  (MCR14_SeafloorSediment_Grainsize.xlsx), and associated metadata.

Autumn olive (Elaeagnus umbellata) presence and proliferation on former surface coal mines in Eastern USA

Released March 01, 2017 00:00 EST

2017, Biological Invasions (19) 179-195

Adam J. Oliphant, R.H. Wynne, Carl E. Zipper, William Ford, P. F. Donovan, Jing Li

Invasive plants threaten native plant communities. Surface coal mines in the Appalachian Mountains are among the most disturbed landscapes in North America, but information about land cover characteristics of Appalachian mined lands is lacking. The invasive shrub autumn olive (Elaeagnus umbellata) occurs on these sites and interferes with ecosystem recovery by outcompeting native trees, thus inhibiting re-establishment of the native woody-plant community. We analyzed Landsat 8 satellite imagery to describe autumn olive’s distribution on post-mined lands in southwestern Virginia within the Appalachian coalfield. Eight images from April 2013 through January 2015 served as input data. Calibration and validation data obtained from high-resolution aerial imagery were used to develop a land cover classification model that identified areas where autumn olive was a primary component of land cover. Results indicate that autumn olive cover was sufficiently dense to enable detection on approximately 12.6 % of post-mined lands within the study area. The classified map had user’s and producer’s accuracies of 85.3 and 78.6 %, respectively, for the autumn olive coverage class. Overall accuracy was assessed in reference to an independent validation dataset at 96.8 %. Autumn olive was detected more frequently on mines disturbed prior to 2003, the last year of known plantings, than on lands disturbed by more recent mining. These results indicate that autumn olive growing on reclaimed coal mines in Virginia and elsewhere in eastern USA can be mapped using Landsat 8 Operational Land Imager imagery; and that autumn olive occurrence is a significant landscape vegetation feature on former surface coal mines in the southwestern Virginia segment of the Appalachian coalfield.

Relations of alpine plant communities across environmental gradients: Multilevel versus multiscale analyses

Released March 01, 2017 00:00 EST

2017, Annals of the Association of American Geographers (107) 41-53

George P. Malanson, Dale L. Zimmerman, Mitch Kinney, Daniel B. Fagre

Alpine plant communities vary, and their environmental covariates could influence their response to climate change. A single multilevel model of how alpine plant community composition is determined by hierarchical relations is compared to a separate examination of those relations at different scales. Nonmetric multidimensional scaling of species cover for plots in four regions across the Rocky Mountains created dependent variables. Climate variables are derived for the four regions from interpolated data. Plot environmental variables are measured directly and the presence of thirty-seven site characteristics is recorded and used to create additional independent variables. Multilevel and best subsets regressions are used to determine the strength of the hypothesized relations. The ordinations indicate structure in the assembly of plant communities. The multilevel analyses, although revealing significant relations, provide little explanation; of the site variables, those related to site microclimate are most important. In multiscale analyses (whole and separate regions), different variables are better explanations within the different regions. This result indicates weak environmental niche control of community composition. The weak relations of the structure in the patterns of species association to the environment indicates that either alpine vegetation represents a case of the neutral theory of biogeography being a valid explanation or that it represents disequilibrium conditions. The implications of neutral theory and disequilibrium explanations are similar: Response to climate change will be difficult to quantify above equilibrium background turnover.

Tsunami travel time maps for Del Norte and Humboldt Counties, CA, reference year 2010

Released March 01, 2017 00:00 EST

2017, Dataset

Jeanne M. Jones, Nathan J. Wood

Tsunami travel time maps for Del Norte and Humboldt Counties in California in vector (shapefile) format for both slow and fast walking speeds and for bridges intact and bridges removed.

Northern bobwhite breeding season ecology on a reclaimed surface mine

Released March 01, 2017 00:00 EST

2017, Journal of Wildlife Management (81) 73-85

Jarred M. Brooke, Evan P. Tanner, David C. Peters, Ashley M. Tanner, Craig A. Harper, Patrick D. Keyser, Joseph D. Clark, John J. Morgan

Surface coal mining and subsequent reclamation of surface mines have converted large forest areas into early successional vegetative communities in the eastern United States. This reclamation can provide a novel opportunity to conserve northern bobwhite (Colinus virginianus). We evaluated the influence of habitat management activities on nest survival, nest-site selection, and brood resource selection on managed and unmanaged units of a reclaimed surface mine, Peabody Wildlife Management Area (Peabody), in west-central Kentucky, USA, from 2010 to 2013. We compared resource selection, using discrete-choice analysis, and nest survival, using the nest survival model in Program MARK, between managed and unmanaged units of Peabody at 2 spatial scales: the composition and configuration of vegetation types (i.e., macrohabitat) and vegetation characteristics at nest sites and brood locations (i.e., microhabitat). On managed sites, we also investigated resource selection relative to a number of different treatments (e.g., herbicide, disking, prescribed fire). We found no evidence that nest-site selection was influenced by macrohabitat variables, but bobwhite selected nest sites in areas with greater litter depth than was available at random sites. On managed units, bobwhite were more likely to nest where herbicide was applied to reduce sericea lespedeza (Lespedeza cuneata) compared with areas untreated with herbicide. Daily nest survival was not influenced by habitat characteristics or by habitat management but was influenced by nest age and the interaction of nest initiation date and nest age. Daily nest survival was greater for older nests occurring early in the breeding season (0.99, SE < 0.01) but was lower for older nests occurring later in the season (0.08, SE = 0.13). Brood resource selection was not influenced by macrohabitat or microhabitat variables we measured, but broods on managed units selected areas treated with herbicide to control sericea lespedeza and were located closer to firebreaks and disked native-warm season grass stands than would be expected at random. Our results suggest the vegetation at Peabody was sufficient without manipulation to support nesting and brood-rearing northern bobwhite at a low level, but habitat management practices improved vegetation for nesting and brood-rearing resource selection. Reproductive rates (e.g., nest survival and re-nesting rates) at Peabody were lower than reported in other studies, which may be related to nutritional deficiencies caused by the abundance of sericea lespedeza. On reclaimed mine lands dominated by sericea lespedeza, we suggest continuing practices such as disking and herbicide application that are targeted at reducing sericea lespedeza to improve the vegetation for nesting and brood-rearing bobwhite.

Matrix inhibition PCR and Microtox® 81.9% screening assay analytical results for samples collected for the Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015

Released March 01, 2017 00:00 EST

2017, Dataset

William B. Schill, William M. Benzel, Shawn C. Fisher, Dale W. Griffin, Daniel K. Jones, Keith A. Loftin, Luke R. Iwanowicz, Timothy J. Reilly

Coastal communities are uniquely vulnerable to sea-level rise (SLR) and severe storms such as hurricanes. These events enhance the dispersion and concentration of natural and anthropogenic chemicals and pathogenic microorganisms that could adversely affect the health and resilience of coastal communities and ecosystems in coming years. The U.S. Geo­logical Survey has developed the Sediment-Bound Contaminant Resiliency and Response (SCoRR) strategy to define baseline and post-event sediment-bound environmental health (EH) stressors. These data document toxicity measured by reduction of the light emission of Aliivibrio (formerly Photobacterium) fischeri and the inhibition of polymerase chain reactions caused by environmental components of aqueous extracts of soil and sediment from selected stations in the northeastern US during the 2015 pilot implementation of the SCoRR strategy in response to Hurricane Joaquin and the 2015 South Carolina flood events.

Chirp seismic-reflection data of field activity S-5-09-SC: San Pedro Basin, offshore southern California from 2009-07-06 to 2009-07-10

Released March 01, 2017 00:00 EST

2017, Dataset

Ray W. Sliter, James E. Conrad, Holly F. Ryan, Peter Triezenberg

This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2009 to explore a possible connection between the San Diego Trough Fault and the San Pedro Basin Fault. The survey is in the San Pedro Basin between Catalina Island and San Pedro, California. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using an Edgetech 512 Chirp subbottom profiling system. Subbottom acoustic penetration spanned tens to hundreds of meters, variable by location.

Minisparker seismic-reflection data of field activity S-5-09-SC: San Pedro Basin, offshore southern California from 2009-07-06 to 2009-07-10

Released March 01, 2017 00:00 EST

2017, Dataset

Ray W. Sliter, James E. Conrad, Holly F Ryan, Peter Triezenberg

This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2009 to explore a possible connection between the San Diego Trough Fault and the San Pedro Basin Fault. The survey is in the San Pedro Basin between Santa Catalina Island and San Pedro, California. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using a SIG 2mille minisparker. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location.

Goose mass and vegetation data, Colville River Delta, Alaska, 2012-2014

Released March 01, 2017 00:00 EST

2017, Dataset

Jerry Hupp

This data release contains three tables of information from the Colville River Delta, Alaska, 2012-2014: offtake of Carex subspathacea, standing crop of C. subspathacea, and snow goose and black brant gosling mass data. Data were collected as part of the USGS Changing Arctic Ecosystems Initiative to understand the response of wildlife to rapid physical changes taking place in the Arctic.

Depth and velocity data in the Lower San Joaquin River, California, 2011-2014

Released March 01, 2017 00:00 EST

2017, Dataset

Mathieu D. Marineau, Scott A. Wright, Dan Whealdon-Haught, Paul J. Kinzel

This data release contains water depth, depth-averaged water velocity, and river stationing (based on 2012 ortho-imagery) in select locations in the Lower San Joaquin River, California, 2011-2014. Between 2011 and 2014, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service (USFWS), collected approximately 105 channel cross-sections and multiple longitudinal profiles, which comprised of nearly 150,000 streamflow-velocity measurements and 246,000 water-depth measurements in various reaches and subreaches of the Lower San Joaquin River between Orestimba Creek and Sturgeon Bend. The data collection locations in the Lower San Joaquin River were selected based on discussions with USFWS to overlap with their sturgeon monitoring sites and areas that may provide beneficial spawning habitat (such as adjacent to gravel bars or known deep scour holes, etc.). An acoustic Doppler current profiler (ADCP) was primarily used to collect the depth and velocity data, however, in 2011 a multibeam sonar was used to map bathymetry in some areas.

Cross-section geometry and sediment-size distribution data from Muddy Creek and North Fork Gunnison River below Paonia Reservoir, Colorado, 2016

Released March 01, 2017 00:00 EST

2017, Dataset

Mark Henneberg, Rodney J. Richards, Cory A. Williams

This data set contains cross-section geometry and sediment-size distribution data collected in the fall of 2016 from Muddy Creek and North Fork Gunnison River below Paonia Reservoir, Colorado. Six cross-sections were surveyed using Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS) methods to document channel geometry below the reservoir in 2015. Those same cross-sections were re-surveyed using the same methods in 2016 to document any changes. One cross-section was surveyed on Muddy Creek below Paonia Reservoir, and five cross-sections were surveyed from North Fork Gunnison River below Paonia Reservoir. All six cross-sections are incorporated in this data release within one shapefile. Pebble-counts were performed at each of the six cross-sections to document sediment-size distributions downstream from the reservoir. Four transects were located in the vicinity of each cross-section, where sediment size was measured and recorded. Transect locations were based on bankfull channel width; with transect 1 located one bankfull channel width upstream from the surveyed cross-section, transect 2 at the surveyed cross-section, and transects 3 and 4 located one and two bankfull channel widths downstream from the surveyed cross-section, respectively. All of the sediment-size distribution data are presented in .CSV files, with one file for each cross-section location incorporating all of the data for each of the four transects at that location.

Cross-Section Geometry and Sediment-Size Distribution Data from Muddy Creek and North Fork Gunnison River below Paonia Reservoir, Colorado, 2015

Released March 01, 2017 00:00 EST

2017, Dataset

Mark Henneberg, Rodney J. Richards, Cory A. Williams

This data set contains cross-section geometry and sediment-size distribution data collected in the fall of 2015 from Muddy Creek and North Fork Gunnison River below Paonia Reservoir, Colorado. Six cross-sections were surveyed using Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS) methods to document channel geometry below the reservoir. One cross-section was surveyed on Muddy Creek below Paonia Reservoir, and five cross-sections were surveyed from North Fork Gunnison River below Paonia Reservoir. All six cross-sections are incorporated in this data release within one shapefile. Pebble-counts were performed at each of the six cross-sections to document sediment-size distributions downstream from the reservoir. Four transects were located in the vicinity of each cross-section, where sediment size was measured and recorded. Transect locations were based on bankfull channel width; with transect 1 located one bankfull channel width upstream from the surveyed cross-section, transect 2 at the surveyed cross-section, and transects 3 and 4 located one and two bankfull channel widths downstream from the surveyed cross-section, respectively. All of the sediment-size distribution data are presented in .CSV files, with one file for each cross-section location incorporating all of the data for each of the four transects at that location.

Amphibian acoustic data from the Arizona 1, Pinenut, and Canyon breccia pipe uranium mines in Arizona

Released March 01, 2017 00:00 EST

2017, Dataset

Jo E. Hinck, Blake R. Hossack, Richard Honeycutt

The data consists of a summary of amphibian acoustic recordings at Canyon, Arizona 1, and Pinenut mines near the Grand Canyon. USGS is currently conducting biological surveys associated with uranium mines on federal lands in Arizona. These surveys include determining the composition of the local amphibian community. Original raw acoustic recordings used to create this summary data table are archived at Columbia Environmental Research Center.

Gridded bathymetry data of Clear Creek Reservoir, Chaffee County, Colorado, 2016

Released March 01, 2017 00:00 EST

2017, Dataset

Michael S. Kohn

To better characterize the water supply capacity of Clear Creek Reservoir, Chaffee County, Colorado, the U.S. Geological Survey, in cooperation with the Pueblo Board of Water Works and Colorado Mountain College, carried out a bathymetry survey of Clear Creek Reservoir. The bathymetry data of the reservoir is presented here in a 1-foot grid. The bathymetry survey was carried out June 6–9, 2016, using a man-operated boat-mounted, multibeam echo sounder integrated with a Global Positioning System (GPS) and a terrestrial survey using real-time kinematic (RTK) Global Navigation Satellite Systems (GNSS). The two collected datasets were merged and imported into geographic information system software. The equipment and methods used in this study allowed water-resource managers to maintain typical reservoir operations, eliminating the need to empty the reservoir to carry out the survey.

Mercury exposure may influence fluctuating asymmetry in waterbirds

Released March 01, 2017 00:00 EST

2017, Environmental Toxicology and Chemistry

Garth Herring, Collin A. Eagles-Smith, Josh Ackerman

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds.

San Francisco Bay-Delta bathymetric/topographic digital elevation model (DEM)

Released March 01, 2017 00:00 EST

2017, Dataset

Theresa Fregoso, Rueen-Fang Wang, Eli Ateljevich, Bruce E. Jaffe

A high-resolution (10-meter per pixel) digital elevation model (DEM) was created for the Sacramento-San Joaquin Delta using both bathymetry and topography data. This DEM is the result of collaborative efforts of the U.S. Geological Survey (USGS) and the California Department of Water Resources (DWR). The base of the DEM is from a 10-m DEM released in 2004 and updated in 2005 (Foxgrover and others, 2005) that used Environmental Systems Research Institute (ESRI), ArcGIS Topo to Raster module to interpolate grids from single beam bathymetric surveys collected by DWR, the Army Corp of Engineers (COE), the National Oceanic and Atmospheric Administration (NOAA), and the USGS, into a continuous surface. The Topo to Raster interpolation method was specifically designed to create hydrologically correct DEMs from point, line, and polygon data (Environmental Systems Research Institute, Inc., 2015). Elevation contour lines were digitized based on the single beam point data for control of channel morphology during the interpolation process. Checks were performed to ensure that the interpolated surfaces honored the source bathymetry, and additional contours and (or) point data were added as needed to help constrain the data. The original data were collected in the tidal datum Mean Lower or Low Water (MLLW) or the National Geodetic Vertical Datum of 1929 (NGVD29). All data were converted to NGVD29.

The 2005 USGS DEM was updated by DWR, first by converting the DEM to the current modern datum of North American Vertical Datum of 1988 (NAVD88) and then by following the methodology of the USGS DEM, established for the 2005 DEM (Foxgrover and others, 2005) for adding newly collected single and multibeam bathymetric data. They then included topographic data from lidar surveys, providing the first DEM that included the land/water interface (Wang and Ateljevich, 2012).

The USGS further updated and expanded the DWR DEM with the inclusion of USGS interpolated sections of single beam bathymetry data collected by the COE and USGS scientists, expanding the DEM to include the northernmost areas of the Sacramento-San Joaquin Delta, and by making use of a two-meter seamless bathymetric/topographic DEM from the USGS EROS Data Center (2013) of the San Francisco Bay region.

The resulting 10-meter USGS DEM encompasses the entirety of Suisun Bay, beginning with the Carquinez Strait in the west, east to California Interstate 5, north following the path of the Yolo Bypass and the Sacramento River up to Knights Landing, and the American River northeast to the Nimbus Dam, and south to areas around Tracy. The DEM incorporates the newest available bathymetry data at the time of release, as well as including, at minimum, a 100-meter band of available topography data adjacent to most shorelines. No data areas within the DEM are areas where no elevation data exists, either due to a gap in the land/water interface, or because lidar was collected over standing water that was then cut out of the DEM.

Environmental Systems Research Institute, Inc., 2015, Topo to Raster:

Foxgrover, A., Smith, R.E., and Jaffe, B.E., 2005, Suisun Bay and Delta Bathymetry:

USGS EROS Data Center, 2013, 2 m Coastal National Elevation Dataset:

Wang, R-F., and Ateljevich, E., 2012, A continuous surface elevation map for modeling, chapter 6 in California Department of Water Resources, Methodology for flow and salinity estimates in the Sacramento-San Joaquin Delta and Suisun Marsh, 33rd Annual Progress Report to the State
Water Resources Control Board:  California Department of Water Resources, Bay-Delta Office, Delta Modeling Section,

Nocturnal insect availability in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley

Released March 01, 2017 00:00 EST

2017, Forest Ecology and Management (391) 127-134

Loraine Ketzler, Christopher Comer, Daniel J. Twedt

Silviculture used to alter forest structure and thereby enhance wildlife habitat has been advocated for bottomland hardwood forest management on public conservation lands in the Mississippi Alluvial Valley. Although some songbirds respond positively to these management actions to attain desired forest conditions for wildlife, the response of other species, is largely unknown. Nocturnal insects are a primary prey base for bats, thereby influencing trophic interactions within hardwood forests. To better understand how silviculture influences insect availability for bats, we conducted vegetation surveys and sampled insect biomass within silviculturally treated bottomland hardwood forest stands. We used passive blacklight traps to capture nocturnal flying insects in 64 treated and 64 untreated reference stands, located on 15 public conservation areas in Arkansas, Louisiana, and Mississippi. Dead wood and silvicultural treatments were positively associated with greater biomass of macro-Lepidoptera, macro-Coleoptera, and all insect taxa combined. Biomass of micro-Lepidoptera was negatively associated with silvicultural treatment but comprised only a small proportion of total biomass. Understanding the response of nocturnal insects to wildlife-forestry silviculture provides insight for prescribed silvicultural management affecting bat species.

Characterization of the quality of water, bed sediment, and fish in Mittry Lake, Arizona, 2014–15

Released March 01, 2017 00:00 EST

2017, Scientific Investigations Report 2017-5008

Edyth Hermosillo, Alissa L. Coes

Water, bed-sediment, and fish sampling was conducted in Mittry Lake, Arizona, in 2014–15 to establish current water-quality conditions of the lake. The parameters of temperature, dissolved-oxygen concentration, specific conductance, and alkalinity were measured in the field. Water samples were collected and analyzed for dissolved major ions, dissolved trace elements, dissolved nutrients, dissolved organic carbon, dissolved pesticides, bacteria, and suspended-sediment concentrations. Bed-sediment and fish samples were analyzed for trace elements, halogenated compounds, total mercury, and methylmercury.

U.S. Environmental Protection Agency secondary maximum contaminant levels in drinking water were exceeded for sulfate, chloride, and manganese in the water samples. Trace-element concentrations were relatively similar between the inlet, middle, and outlet locations. Concentrations for nutrients in all water samples were below the Arizona Department of Environmental Quality’s water-quality standards for aquatic and wildlife uses, and all bacteria levels were below the Arizona Department of Environmental Quality’s recommended recreational water-quality criteria. Three out of 81 pesticides were detected in the water samples.

Trace-element concentrations in bed sediment were relatively consistent between the inlet, middle, and outlet locations. Lead, manganese, nickel, and zinc concentrations, however, decreased from the inlet to outlet locations. Concentrations for lead, nickel, and zinc in some bed-sediment samples exceeded consensus-based sediment-quality guidelines probable effect concentrations. Eleven out of 61 halogenated compounds were detected in bed sediment at the inlet location, whereas three were detected at the middle location, and five were detected at the outlet location. No methylmercury was detected in bed sediment. Total mercury was detected in bed sediment at concentrations below the consensus-based sediment-quality guidelines probable effect concentration.

Sixteen trace elements were detected in at least one of the fish-tissue samples, and trace-element concentrations were relatively consistent between the three fish-tissue samples. Seven halogenated compounds were detected in at least one of the whole-body fish samples; four to five compounds were detected in each fish. One fish-tissue sample exceeded the U.S. Environmental Protection Agency human health consumption criteria for methylmercury.

Sources and dispersal of land-based runoff from small Hawaiian drainages to a coral reef: Insights from geochemical signatures

Released March 01, 2017 00:00 EST

2017, Estuarine, Coastal and Shelf Science (188) 69-80

Renee K. Takesue, Curt Storlazzi

Land-based sediment and contaminant runoff is a major threat to coral reefs, and runoff reduction efforts would benefit from knowledge of specific runoff sources. Geochemical signatures of small drainage basins were determined in the fine fraction of soil and sediment, then used in the nearshore region of a coral reef-fringed urban embayment on southeast Oahu, Hawaii, to describe sources and dispersal of land-based runoff. The sedimentary rare earth element ratio (La/Yb)N showed a clear distinction between the two main rock types in the overall contributing area, tholeiitic and alkalic olivine basalt. Based on this geochemical signature it was apparent that the majority of terrigenous sediment on the reef flat originated from geologically old tholeiitic drainages. Sediment from one of five tholeiitic drainages had a distinct geochemical signature, and sediment with this signature was dispersed on the reef flat 2 km west and 150 m offshore of the contributing basin. Sediment and the anthropogenic metals Cd, Pb, and Zn were entrained in runoff from the most heavily urbanized region of the watershed. Although anthropogenic Cd and Zn had localized distributions close to shore, anthropogenic Pb was found associated with fine sediment on the westernmost part of the reef flat and 400 m offshore, illustrating how trade-wind-driven sediment transport can increase the scale of runoff impacts to nearshore communities. Our findings show that sediment geochemical signatures can provide insights about the source and dispersal of land-based runoff in shallow coastal environments. The application of such knowledge to watershed management and habitat remediation efforts can aid in the protection and restoration of runoff-impacted coastal ecosystems worldwide.

Volcanic gas measurements at Mount Cleveland, 14-15 August 2015

Released March 01, 2017 00:00 EST

2017, Dataset

Cynthia A. Werner, Christoph Kern, Peter Kelly

On 14-15 August 2015, helicopter-based measurements were made of the volcanic gases emitted from Mount Cleveland, AK. An upward-looking differential optical absorption spectroscopy (DOAS) system was used to measure incident scattered solar ultraviolet radiation while traversing beneath the plume on multiple occasions 14-15 August. This data was used to derive SO2 emission rates. Additionally, a Multi-Component Gas Analyzer System (Multi-GAS) was used to make measurements of trace gas concentrations while on a dedicated measurement flight passing through the gas plume on 15 August (19:15 - 19:56 UTC). Radiance spectra and gas compositions were both recorded at 1 second time resolution. Each spectrum and gas measurement was stamped with the GPS time and location. Each spectrum was saved in a separate ASCII file which includes 2048 radiances measured in the 285 - 430 nm spectral region and metadata associated with each acquisition. The Multi-GAS measurements are saved in a spreadsheet in the *.csv format.

Data for herpetofaunal inventories of the national parks of South Florida and the Caribbean: Volume IV, Biscayne National Park

Released March 01, 2017 00:00 EST

2017, Dataset

Kenneth G. Rice, J. Hardin Waddle, Marquette E. Crockett, Brian M. Jeffery, H. Franklin Percival

The Comprehensive Everglades Restoration Plan (CERP) requires the use of ecological indicators to measure the success of restoration efforts. The Everglades amphibian community is ideal because amphibians are present in all habitats and under all hydrologic regimes. During Everglades restoration, hydrologic patterns will change and the response of ecological indicators will determine success. Fourteen amphibian species were detected through visual encounter surveys, vocalization surveys and trapping methods throughout the study and the occurrence information collected in this project database.

Data for herpetofaunal inventories of the national parks of South Florida and the Caribbean: Volume III, Big Cypress National Preserve

Released March 01, 2017 00:00 EST

2017, Dataset

Kenneth G. Rice, Hardin Waddle, Marquette E. Crockett, Brian M. Jeffery, H. Franklin Percival

The Comprehensive Everglades Restoration Plan (CERP) requires the use of ecological indicators to measure the success of restoration efforts. The Everglades amphibian community is ideal because amphibians are present in all habitats and under all hydrologic regimes. During Everglades restoration, hydrologic patterns will change and the response of ecological indicators will determine success. Fourteen amphibian species were detected through visual encounter surveys, vocalization surveys and trapping methods throughout the study and the occurrence information collected in this project database.

Data for herpetofaunal inventories of the national parks of South Florida and the Caribbean: Volume II, Virgin Islands National Park

Released March 01, 2017 00:00 EST

2017, Dataset

Kenneth G. Rice, Hardin Waddle, Marquette E. Crockett, Raymond R. Carthy, H. Franklin Percival

The Comprehensive Everglades Restoration Plan (CERP) requires the use of ecological indicators to measure the success of restoration efforts. The Everglades amphibian community is ideal because amphibians are present in all habitats and under all hydrologic regimes. During Everglades restoration, hydrologic patterns will change and the response of ecological indicators will determine success. Fourteen amphibian species were detected through visual encounter surveys, vocalization surveys and trapping methods throughout the study and the occurrence information collected in this project database.

North American Amphibian Monitoring Program (NAAMP) anuran detection data from the eastern and central United States (1994-2015)

Released March 01, 2017 00:00 EST

2017, Dataset

Tasha M. Foreman, Evan H. Campbell Grant, Linda A. Weir

The North American Amphibian Monitoring Program (NAAMP) was a collaborative citizen science effort between the US Geological Survey (USGS) and 26 Partners (state agencies, universities, and nonprofits) for monitoring calling amphibian populations over much of the eastern and central United States. Initiated in 1997 in response to needs set forth by the Declining Amphibian Populations Task Force in 1994 regarding increased anecdotal observations of global amphibian declines, NAAMP was designed to provide scientifically and statistically defensible, long-term distribution and trends data for calling amphibian populations at the state and regional level in the United States. The USGS discontinued coordination of the program at the conclusion of the 2015 field season. Modeled after the USGS Breeding Bird Survey, NAAMP used a network of random and state-requested non-random roadside routes with listening stops near wetlands to collect frog and toad occupancy and environmental data in predominantly unprotected lands. Data collection and verification under a unified protocol began in 2001 and continued through 2015 with the addition of observer assessment scores in 2006. The USGS utilized verified 2001-2015 data from random routes to produce occupancy trend reports for anuran species of the Northeast, Southeast, and Midwest regions and states of the United States. This dataset includes all raw, verified NAAMP data from 1997 through 2015 and also raw, verified data from Partner States that precede the program (1994-1996). Data preceding 2001 followed variations of the unified protocol. Please refer to metadata for additional information regarding protocol and a list of the represented states and see the Species.csv file for the list of 58 represented species.

Earthquake catalogs for the 2017 Central and Eastern U.S. short-term seismic hazard model

Released March 01, 2017 00:00 EST

2017, Dataset

Charles S. Mueller

The U. S. Geological Survey (USGS) makes long-term seismic hazard forecasts that are used in building codes. The hazard models usually consider only natural seismicity; non-tectonic (man-made) earthquakes are excluded because they are transitory or too small. In the past decade, however, thousands of earthquakes related to underground fluid injection have occurred in the central and eastern U.S. (CEUS), and some have caused damage.  In response, the USGS is now also making short-term forecasts that account for the hazard from these induced earthquakes. Seismicity statistics are analyzed to develop recurrence models, accounting for catalog completeness. In the USGS hazard modeling methodology, earthquakes are counted on a map grid, recurrence models are applied to estimate the rates of future earthquakes in each grid cell, and these rates are combined with maximum-magnitude models and ground-motion models to compute the hazard The USGS published a forecast for the years 2016 and 2017.

Here, we document the development of the seismicity catalogs for the 2017 CEUS short-term hazard model.  A uniform earthquake catalog is assembled by combining and winnowing pre-existing source catalogs. The initial, final, and supporting earthquake catalogs are made available here.

Geochemical and geochronologic data from the Hall Creek caldera, Toiyabe Range, Nevada

Released March 01, 2017 00:00 EST

2017, Dataset

Joseph P. Colgan, Christopher D. Henry

The magmatic, tectonic, and topographic evolution of what is now the northern Great Basin remains controversial, notably the temporal and spatial relation between magmatism and extensional faulting. This controversy is exemplified in the northern Toiyabe Range of central Nevada, where previous geologic mapping suggested the presence of a caldera that sourced the late Eocene (34.0 mega-annum [Ma]) tuff of Hall Creek. This region was also inferred to be the locus of large-magnitude middle Tertiary extension (more than 100 percent strain) localized along the Bernd Canyon detachment fault, and to be the approximate location of a middle Tertiary paleodivide that separated east and west-draining paleovalleys. Geologic mapping, 40Ar/39Ar dating, and geochemical analyses document the geologic history and extent of the Hall Creek caldera, define the regional paleotopography at the time it formed, and clarify the timing and kinematics of post-caldera extensional faulting. During and after late Eocene volcanism, the northern Toiyabe Range was characterized by an east-west trending ridge in the area of present-day Mount Callaghan, probably localized along a Mesozoic anticline. Andesite lava flows erupted around 35–34 Ma ponded hundreds of meters thick in the erosional low areas surrounding this structural high, particularly in the Simpson Park Mountains. The Hall Creek caldera formed ca. 34.0 Ma during eruption of the approximately 400 cubic kilometers (km3) tuff of Hall Creek, a moderately crystal-rich rhyolite (71–77 percent SiO2) ash-flow tuff. Caldera collapse was piston-like with an intact floor block, and the caldera filled with thick (approximately 2,600 meters) intracaldera tuff and interbedded breccia lenses shed from the caldera walls. The most extensive exposed megabreccia deposits are concentrated on or close to the caldera floor in the southwestern part of the caldera. Both silicic and intermediate post-caldera lavas were locally erupted within 400 thousand years of the main eruption, and for the next approximately 10 million years sedimentary rocks and distal tuffs sourced from calderas farther west ponded in the caldera basin surrounding low areas nearby. Patterns of tuff deposition indicate that the area was characterized by east-west trending paleovalleys and ridges in the late Eocene and Oligocene, which permitted tuffs to disperse east-west but limited their north-south extent. Although a low-angle fault contact of limited extent separates Cambrian and Ordovician strata in the southwestern part of the study area, there is no evidence that this fault cuts overlying Tertiary rocks. Total extensional strain across the caldera is on the order of 15 percent, and there is no evidence for progressive tilting of 34–25 Ma rocks that would indicate protracted Eocene–Oligocene extension. The caldera appears to have been tilted as an intact block after 25 Ma, probably during the middle Miocene extensional faulting well documented to the north and south of the study area.

Microsomal EROD data of fish liver sample assay from species collected in the Salt and Gila Rivers, Arizona

Released March 01, 2017 00:00 EST

2017, Dataset

Diane Nicks

This dataset includes microsomal ERDO data from an assay done with liver samples from several fish species that are found in Arizona at sites that are being assessed for PBDE contamination. The data was created in September and October 2016.

Partitioning evapotranspiration into green and blue water sources in the conterminous United States

Released March 01, 2017 00:00 EST

2017, Dataset

Naga Manohar Velpuri, Gabriel Senay

In this study, we combined two actual evapotranspiration datasets (ET), one obtained from a root zone water balance model and another from an energy balance model, to partition annual ET into green (rainfall-based) and blue (surface/groundwater) water sources. Time series maps of green water ET (GWET) and blue water ET (BWET) are produced for the conterminous United States (CONUS) over 2001–2015.

Assessment of pulsed DC electric field to guide downstream migrating sea lamprey in experimental flume at USGS Conte Anadromous Fish Lab, Turners Falls, MA (December 2013)

Released March 01, 2017 00:00 EST

2017, Dataset

Scott M. Miehls, Nicholas Johnson, Alexander J. Haro

This is a tabular data set that contains records of water velocity, depth, temperature and trial information such as start and stop times and date for experimental trials testing the effect of an electric field on the movement patterns and distribution of juvenile sea lamprey moving downstream in an experimental flume. Distribution is recorded for each individual lamprey as presence (1) or absence (0) in a series of downstream collection nets positions laterally across the flume. The data is formatted as comma delimited and contains no special characters. The trails were conducted during December 2 through December 15, 2013 in a 6 meter wide experimental flume at the Conte Anadromous Fish Research Lab in Turners Falls, MA.

Acidification and Increasing CO2 Flux Associated with Five, Springs Coast, Florida Springs (1991-2014)

Released March 01, 2017 00:00 EST

2017, Dataset

Kira E. Barrera, Lisa L. Robbins

Scientists from the South West Florida Management District (SWFWMD) acquired and analyzed over 20 years of seasonally-sampled hydrochemical data from five first-order-magnitude (springs that discharge 2.83 m3 s-1 or more) coastal springs located in west-central Florida. These data were subsequently obtained by the U.S. Geological Survey (USGS) for further analyses and interpretation. The spring study sites (Chassahowitzka, Homosassa, Kings Bay, Rainbow, and Weeki Wachee), which are fed by the Floridan Aquifer system and discharge into the Gulf of Mexico were investigated to identify temporal and spatial trends of pH, alkalinity, partial pressure of carbon dioxide (pCO2) and CO2 flux.

Evapotranspiration (ET) data at Immokalee row crop site, Collier County, Florida, September 22, 2008 - January 8, 2009

Released March 01, 2017 00:00 EST

2017, Dataset

Amy Swancar

This U.S. Geological Survey (USGS) data release consists of evapotranspiration measurements made at the USGS Immokalee row crop climate station beginning September 22, 2008 and ending January 8, 2009. Daily evapotranspiration rates corrected to a near-surface energy-budget varied from 0.1 millimeter (9/28/2008) to 3.3 millimeters (9/24/2008). The eddy-covariance method was used, with high-frequency sensors installed above an experimental field planted in green peppers to measure sensible and latent heat fluxes. Ancillary meteorological data are also included in the data set: net radiation, soil temperature and moisture, air temperature, relative humidity, wind speed and direction, and ground-water level. Data were collected at 30-minute resolution, with evapotranspiration corrected to the near-surface energy-budget at that timescale. The study was conducted at an experimental field on the University of Florida Southwest Florida Research and Education Center (SWFREC) in Immokalee, Florida (Latitude 26 27 40 North Longitude 81 26 24 West, in degrees minutes seconds, North American Datum 83, Section 20, Township 46S, Range 29E). The full data release associated with this site consists of: 1.  Immokalee row crop evapotranspiration, 30-minute data, from September 22, 2008 through January 8, 2009 (comma delimited text format) 2. Immokalee row crop evapotranspiration, daily data, from September 23, 2008 through January 7, 2009 (comma delimited text format) including an ancillary file: Vegetation and equipment photographs (zipped jpeg files).

Storm-impact scenario XBeach model inputs and tesults

Released March 01, 2017 00:00 EST

2017, Dataset

Rangley Mickey, Joseph W. Long, David M. Thompson, Nathaniel G. Plant, P. Soupy Dalyander

The XBeach model input and output of topography and bathymetry resulting from simulation of storm-impact scenarios at the Chandeleur Islands, LA, as described in USGS Open-File Report 2017–1009 (, are provided here. For further information regarding model input generation and visualization of model output topography and bathymetry refer to USGS Open-File Report 2017–1009 (

Avian point count, habitat, and covariate data for subarctic bird abundance, Seward Peninsula, Alaska, 2012-2014

Released March 01, 2017 00:00 EST

2017, Dataset

Sarah J. Thompson, Colleen M. Handel

This data set contains avian counts by species and habitat type as well as covariate information used for analysis of bird surveys conducted between 2012 and 2014 on the Seward Peninsula, Alaska, as part of the USGS Changing Arctic Ecosystems Initiative. We conducted 1,208 point counts on 12 study blocks from 2012–2014 in northwestern Alaska, using repeated surveys to account for imperfect detection of birds. We considered the importance of shrub height, density of low and tall shrubs (i.e. shrubs >0.5 m tall), percent of ground cover attributed to shrubs (including dwarf shrubs < 0.5 m tall), and percent of herbaceous plant cover in predicting bird abundance

Five hydrologic and landscape databases for select National Wildlife Refuges in southeastern United States

Released March 01, 2017 00:00 EST

2017, Dataset

Gary R. Buell, Laura N. Gurley, Daniel L. Calhoun, Alexandria M. Hunt

Five hydrologic and landscape databases were developed by the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, for select National Wildlife Refuges (NWRs) in southeastern United States: (1) the Cahaba River NWR and contributing watersheds in Alabama, (2) the Caloosahatchee and J.N. "Ding" Darling NWRs and contributing watersheds in Florida, (3) the Clarks River NWR and contributing watersheds in Kentucky, Tennessee, and Mississippi, (4) the Lower Suwannee NWR and contributing watersheds in Georgia and Florida, and (5) the Okefenokee NWR and contributing watersheds in Georgia and Florida. The databases were developed as an assessment and evaluation tool to use in examining refuge-specific hydrologic patterns and trends as related to water availability and water quality for refuge ecosystems, habitats, and target species. They include hydrologic time-series data, statistics on landscape and hydrologic time-series data, and hydro-ecological metrics that can be used to assess refuge hydrologic conditions. The databases are described and documented in detail in Open File Report 2017-1018.

Germination and growth of native and invasive plants on soil associated with biological control of tamarisk (Tamarix spp.)

Released March 01, 2017 00:00 EST

2016, Invasive Plant Science and Management (9) 290-307

Rebecca A. Sherry, Patrick B. Shafroth, Jayne Belnap, Steven M. Ostoja, Sasha C. Reed

Introductions of biocontrol beetles (tamarisk beetles) are causing dieback of exotic tamarisk in riparian zones across the western United States, yet factors that determine plant communities that follow tamarisk dieback are poorly understood. Tamarisk-dominated soils are generally higher in nutrients, organic matter, and salts than nearby soils, and these soil attributes might influence the trajectory of community change. To assess physical and chemical drivers of plant colonization after beetle-induced tamarisk dieback, we conducted separate germination and growth experiments using soil and litter collected beneath defoliated tamarisk trees. Focal species were two common native (red threeawn, sand dropseed) and two common invasive exotic plants (Russian knapweed, downy brome), planted alone and in combination. Nutrient, salinity, wood chip, and litter manipulations examined how tamarisk litter affects the growth of other species in a context of riparian zone management. Tamarisk litter, tamarisk litter leachate, and fertilization with inorganic nutrients increased growth in all species, but the effect was larger on the exotic plants. Salinity of 4 dS m−1 benefitted Russian knapweed, which also showed the largest positive responses to added nutrients. Litter and wood chips generally delayed and decreased germination; however, a thinner layer of wood chips increased growth slightly. Time to germination was lengthened by most treatments for natives, was not affected in exotic Russian knapweed, and was sometimes decreased in downy brome. Because natives showed only small positive responses to litter and fertilization and large negative responses to competition, Russian knapweed and downy brome are likely to perform better than these two native species following tamarisk dieback.

Concordance in diagnostic testing for respiratory pathogens of bighorn sheep

Released March 01, 2017 00:00 EST

2016, Wildlife Society Bulletin (101) 25575-25587

Daniel P. Walsh, E. Frances Cassirer, Michael D. Bonds, Daniel R. Brown, William H. Edwards, Glen C. Weiser, Mark L. Drew, Robert E. Briggs, Karen A. Fox, Michael W. Miller, Sudarvili Shanthalingam, Subramaniam Srikumaran, Thomas E. Besser

Reliable diagnostic tests are essential for disease investigation and management. This is particularly true for diseases of free-ranging wildlife where sampling is logistically difficult precluding retesting. Clinical assays for wildlife diseases frequently vary among laboratories because of lack of appropriate standardized commercial kits. Results of diagnostic testing may also be called into question when investigators report different etiologies for disease outbreaks, despite similar clinical and pathologic findings. To evaluate reliability of diagnostic testing for respiratory pathogens of bighorn sheep (Ovis canadensis), we conducted a series of ring tests across 6 laboratories routinely involved in detection of Mycoplasma ovipneumoniae, Pasteurellaceae, lktA (the Pasteurellaceae gene encoding leukotoxin), and 3 reference laboratories. Consistency of results for replicate samples within laboratories was high (median agreement = 1.0). Agreement between laboratories was high for polymerase chain reaction (PCR) detection of M. ovipneumoniae and culture isolation of Mannheimia spp. and Bibersteinia trehalosi(median agreement = 0.89–0.95, Kappa = 0.65–0.74), and lower for PCR detection of Mannheimiaspp. lktA (median agreement = 0.58, Kappa = 0.12). Most errors on defined status samples were false negatives, suggesting test sensitivity was a greater problem than specificity. However, tests for M. haemolytica and lktA yielded some false positive results. Despite differences in testing protocols, median agreement among laboratories and correct classification of controls for most agents was ≥0.80, meeting or exceeding the standard required by federal proficiency testing programs. This information is valuable for interpreting test results, laboratory quality assessments, and advancing diagnosis of respiratory disease in wild sheep. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Paleogeographic implications of Late Miocene lacustrine and nonmarine evaporite deposits in the Lake Mead region: Immediate precursors to the Colorado River

Released March 01, 2017 00:00 EST

2016, Geosphere (12) 721-767

James E Faulds, Charlotte Schreiber, Victoria Langenheim, Nicholas H Hinz, Tom Shaw, Matthew T. Heizler, Michael E Perkins, Mohammed El Tabakh, Michael J. Kunk

Thick late Miocene nonmarine evaporite (mainly halite and gypsum) and related lacustrine limestone deposits compose the upper basin fill in half grabens within the Lake Mead region of the Basin and Range Province directly west of the Colorado Plateau in southern Nevada and northwestern Arizona. Regional relations and geochronologic data indicate that these deposits are late synextensional to postextensional (ca. 12–5 Ma), with major extension bracketed between ca. 16 and 9 Ma and the abrupt western margin of the Colorado Plateau established by ca. 9 Ma. Significant accommodation space in the half grabens allowed for deposition of late Miocene lacustrine and evaporite sediments. Concurrently, waning extension promoted integration of initially isolated basins, progressive enlargement of drainage nets, and development of broad, low gradient plains and shallow water bodies with extensive clastic, carbonate, and/or evaporite sedimentation. The continued subsidence of basins under restricted conditions also allowed for the preservation of particularly thick, localized evaporite sequences prior to development of the through-going Colorado River.

The spatial and temporal patterns of deposition indicate increasing amounts of freshwater input during the late Miocene (ca. 12–6 Ma) immediately preceding arrival of the Colorado River between ca. 5.6 and 4.9 Ma. In axial basins along and proximal to the present course of the Colorado River, evaporite deposition (mainly gypsum) transitioned to lacustrine limestone progressively from east to west, beginning ca. 12–11 Ma in the Grand Wash Trough in the east and shortly after ca. 5.6 Ma in the western Lake Mead region. In several satellite basins to both the north and south of the axial basins, evaporite deposition was more extensive, with thick halite (>200 m to 2.5 km thick) accumulating in the Hualapai, Overton Arm, and northern Detrital basins. Gravity and magnetic lows suggest that thick halite may also lie within the northern Grand Wash, Mesquite, southern Detrital, and northeastern Las Vegas basins. New tephrochronologic data indicate that the upper part of the halite in the Hualapai basin is ca. 5.6 Ma, with rates of deposition of ∼190–450 m/m.y., assuming that deposition ceased approximately coincidental with the arrival of the Colorado River. A 2.5-km-thick halite sequence in the Hualapai basin may have accumulated in ∼5–7 m.y. or ca. 12–5 Ma, which coincides with lacustrine limestone deposition near the present course of the Colorado River in the region.

The distribution and similar age of the limestone and evaporite deposits in the region suggest a system of late Miocene axial lakes and extensive continental playas and salt pans. The playas and salt pans were probably fed by both groundwater discharge and evaporation from shallow lakes, as evidenced by sedimentary textures. The elevated terrain of the Colorado Plateau was likely a major source of water that fed the lakes and playas. The physical relationships in the Lake Mead region suggest that thick nonmarine evaporites are more likely to be late synextensional and accumulate in basins with relatively large catchments proximal to developing river systems or broad elevated terranes. Other basins adjacent to the lower Colorado River downstream of Lake Mead, such as the Dutch Flat, Blythe-McCoy, and Yuma basins, may also contain thick halite deposits.

Fire effects on wildlife in Central Hardwoods and Appalachian regions

Released March 01, 2017 00:00 EST

2016, Fire Ecology (12) 127-159

Craig A. Harper, William Ford, Marcus A. Lashley, Christopher Moorman, Michael C. Stambaugh

Fire is being prescribed and used increasingly to promote ecosystem restoration (e.g., oak woodlands and savannas) and to manage wildlife habitat in the Central Hardwoods and Appalachian regions, USA. However, questions persist as to how fire affects hardwood forest communities and associated wildlife, and how fire should be used to achieve management goals. We provide an up-to-date review of fire effects on various wildlife species and their habitat in the Central Hardwoods and Appalachians. Documented direct effects (i.e., mortality) on wildlife are rare. Indirect effects (i.e., changes in habitat quality) are influenced greatly by light availability, fire frequency, and fire intensity. Unless fire intensity is great enough to kill a portion of the overstory, burning in closed-canopy forests has provided little benefit for most wildlife species in the region because it doesn’t result in enough sunlight penetration to elicit understory response. Canopy reduction through silvicultural treatment has enabled managers to use fire more effectively. Fire intensity must be kept low in hardwoods to limit damage to many species of overstory trees. However, wounding or killing trees with fire benefits many wildlife species by allowing increased sunlight to stimulate understory response, snag and subsequent cavity creation, and additions of large coarse woody debris. In general, a fire-return interval of 2 yr to 7 yr benefits a wide variety of wildlife species by providing a diverse structure in the understory; increasing browse, forage, and soft mast; and creating snags and cavities. Historically, dormant-season fire was most prevalent in these regions, and it still is when most prescribed fire is implemented in hardwood systems as burn-days are relatively few in the growing season of May through August because of shading from leaf cover and high fuel moisture. Late growing-season burning increases the window for burning, and better control on woody composition is possible. Early growing-season fire may pose increased risk for some species, especially herpetofauna recently emerged from winter hibernacula (April) or forest songbirds that nest in the understory (May to June). However, negative population-level effects are unlikely unless the burned area is relatively large and early growing-season fire is used continually. We did not find evidence that fire is leading to population declines for any species, including Endangered Species Act (ESA)-listed species (e.g., Indiana bat [Myotis sodalis Mill. Allen] or northern long-eared bat [M. septentrionalis Trouess.]). Instead, data indicate that fire can enhance habitat for bats by increasing suitability of foraging and day-roost sites. Similarly, concern over burning and displacement of woodland salamanders (Plethodontidae), another taxa of heightened conservation concern, is alleviated when fire is prescribed along ecologically appropriate aspect and slope gradients and not forced into mesic, high site index environments where salamanders are most common. Because topography across the Central Hardwoods and Appalachians is diverse, we contend that applying fire on positions best suited for burning is an effective approach to increase regional landscape heterogeneity and biological diversity. Herein, we offer prescriptive concepts for burning for various wildlife species and guilds in the Central Hardwoods and Appalachians.

Northern long-eared bat day-roosting and prescribed fire in the central Appalachians

Released March 01, 2017 00:00 EST

2016, Fire Ecology (12) 13-27

William Ford, Alexander Silvis, Joshua B. Johnson, John W. Edwards, Milu Karp

The northern long-eared bat (Myotis septentrionalis Trovessart) is a cavity-roosting species that forages in cluttered upland and riparian forests throughout the oak-dominated Appalachian and Central Hardwoods regions. Common prior to white-nose syndrome, the population of this bat species has declined to functional extirpation in some regions in the Northeast and Mid-Atlantic, including portions of the central Appalachians. Our long-term research in the central Appalachians has shown that maternity colonies of this species form non-random assorting networks in patches of suitable trees that result from long- and short-term forest disturbance processes, and that roost loss can occur with these disturbances. Following two consecutive prescribed burns on the Fernow Experimental Forest in the central Appalachians, West Virginia, USA, in 2007 to 2008, post-fire counts of suitable black locust (Robinia pseudoacacia L.; the most selected species for roosting) slightly decreased by 2012. Conversely, post-fire numbers of suitable maple (Acer spp. L.), primarily red maple (Acer rubrum L.), increased by a factor of three, thereby ameliorating black locust reduction. Maternity colony network metrics such as roost degree (use) and network density for two networks in the burned compartment were similar to the single network observed in unburned forest. However, roost clustering and degree of roost centralization was greater for the networks in the burned forest area. Accordingly, the short-term effects of prescribed fire are slightly or moderately positive in impact to day-roost habitat for the northern long-eared bat in the central Appalachians from a social dynamic perspective. Listing of northern long-eared bats as federally threatened will bring increased scrutiny of immediate fire impacts from direct take as well as indirect impacts from long-term changes to roosting and foraging habitat in stands being returned to historic fire-return conditions. Unfortunately, definitive impacts will remain speculative owing to the species’ current rarity and the paucity of forest stand data that considers tree condition or that adequately tracks snags spatially and temporally.

A gas-tracer injection for evaluating the fate of methane in a coastal plain stream: Degassing versus in-stream oxidation

Released March 01, 2017 00:00 EST

2016, Environmental Science & Technology (50) 10504-10511

Victor M. Heilweil, D. Kip Solomon, Thomas H. Darrah, Troy E. Gilmore, David P. Genereux

Methane emissions from streams and rivers have recently been recognized as an important component of global greenhouse budgets. Stream methane is lost as evasion to the atmosphere or in-stream methane oxidation. Previous studies have quantified evasion and oxidation with point-scale measurements. In this study, dissolved gases (methane, krypton) were injected into a coastal plain stream in North Carolina to quantify stream CH4 losses at the watershed scale. Stream-reach modeling yielded gas transfer and oxidation rate constants of 3.2 ± 0.5 and 0.5 ± 1.5 d–1, respectively, indicating a ratio of about 6:1. The resulting evasion and oxidation rates of 2.9 mmol m–2 d–1 and 1,140 nmol L–1 d–1, respectively, lie within ranges of published values. Similarly, the gas transfer velocity (K600) of 2.1 m d–1 is consistent with other gas tracer studies. This study illustrates the utility of dissolved-gas tracers for evaluating stream methane fluxes. In contrast to point measurements, this approach provides a larger watershed-scale perspective. Further work is needed to quantify the magnitude of these fluxes under varying conditions (e.g., stream temperature, nutrient load, gradient, flow rate) at regional and global scales before reliable bottom-up estimates of methane evasion can be determined at global scales.

Toxicants in folk remedies: Implications of elevated blood lead in an American-born infant due to imported diaper powder

Released March 01, 2017 00:00 EST

2016, Environmental Geochemistry and Health

Mateusz P. Karwowski, Suzette A. Morman, Geoffrey S. Plumlee, Terence Law, Mark Kellogg, Alan D. Woolf

Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13–18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant’s venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.

Assessing North American multimodel ensemble (NMME) seasonal forecast skill to assist in the early warning of hydrometeorological extremes over East Africa

Released March 01, 2017 00:00 EST

2016, Climate Dynamics

Shraddhanand Shukla, Jason B. Roberts, Hoell. Andrew, Chris Funk, Franklin R. Robertson, Benjamin Kirtmann

The skill of North American multimodel ensemble (NMME) seasonal forecasts in East Africa (EA), which encompasses one of the most food and water insecure areas of the world, is evaluated using deterministic, categorical, and probabilistic evaluation methods. The skill is estimated for all three primary growing seasons: March–May (MAM), July–September (JAS), and October–December (OND). It is found that the precipitation forecast skill in this region is generally limited and statistically significant over only a small part of the domain. In the case of MAM (JAS) [OND] season it exceeds the skill of climatological forecasts in parts of equatorial EA (Northern Ethiopia) [equatorial EA] for up to 2 (5) [5] months lead. Temperature forecast skill is generally much higher than precipitation forecast skill (in terms of deterministic and probabilistic skill scores) and statistically significant over a majority of the region. Over the region as a whole, temperature forecasts also exhibit greater reliability than the precipitation forecasts. The NMME ensemble forecasts are found to be more skillful and reliable than the forecast from any individual model. The results also demonstrate that for some seasons (e.g. JAS), the predictability of precipitation signals varies and is higher during certain climate events (e.g. ENSO). Finally, potential room for improvement in forecast skill is identified in some models by comparing homogeneous predictability in individual NMME models with their respective forecast skill.

Snake fungal disease: An emerging threat to wild snakes

Released March 01, 2017 00:00 EST

2016, Dataset

Jeffrey M. Lorch

Snake fungal disease (SFD) is an emerging disease of wild snakes in eastern North America caused by the fungus Ophidiomyces ophiodiicola. The data presented here describe: 1) the types of fungi recovered in culture from the skin of snakes with and without fungal skin infections, 2) the presence or absence of skin lesions in populations of snakes surveyed at several sites in Wisconsin and Minnesota, and 3) the various species of snakes that have been found to harbor O. ophiodiicola.

Partly cloudy with a chance of migration: Weather, radars, and aeroecology

Released March 01, 2017 00:00 EST

2012, Bulletin of the American Meteorological Society (93) 669-686

Phillip B. Chilson, Winifred F. Frick, Jeffrey F. Kelly, Kenneth W. Howard, Ronald P. Larkin, Robert H. Diehl, John K. Westbrook, T. Adam Kelly, Thomas H. Kunz

Aeroecology is an emerging scientific discipline that integrates atmospheric science, Earth science, geography, ecology, computer science, computational biology, and engineering to further the understanding of biological patterns and processes. The unifying concept underlying this new transdisciplinary field of study is a focus on the planetary boundary layer and lower free atmosphere (i.e., the aerosphere), and the diversity of airborne organisms that inhabit and depend on the aerosphere for their existence. Here, we focus on the role of radars and radar networks in aeroecological studies. Radar systems scanning the atmosphere are primarily used to monitor weather conditions and track the location and movements of aircraft. However, radar echoes regularly contain signals from other sources, such as airborne birds, bats, and arthropods. We briefly discuss how radar observations can be and have been used to study a variety of airborne organisms and examine some of the many potential benefits likely to arise from radar aeroecology for meteorological and biological research over a wide range of spatial and temporal scales. Radar systems are becoming increasingly sophisticated with the advent of innovative signal processing and dual-polarimetric capabilities. These capabilities should be better harnessed to promote both meteorological and aeroecological research and to explore the interface between these two broad disciplines. We strongly encourage close collaboration among meteorologists, radar scientists, biologists, and others toward developing radar products that will contribute to a better understanding of airborne fauna.

Winter 2016, Part B—Coastal oblique aerial photographs collected from Assateague Island, Virginia, to Montauk Point, New York, March 8–9, 2016

Released February 28, 2017 15:15 EST

2017, Data Series 1030

Karen L. M. Morgan

The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in the vulnerability of the Nation's coasts to extreme storms. On March 8–9, 2016, the USGS conducted an oblique aerial photographic survey from Assateague Island, Virginia, to Montauk Point, New York, aboard a Cessna 182 aircraft at an altitude of 500 feet and approximately 1,200 feet offshore. This mission was conducted to collect baseline data for assessing incremental changes in the beach and nearshore area and can be used to assess future coastal change.

The photographs in this report document the state of the barrier islands and other coastal features at the time of the survey.

Winter 2016, Part A—Coastal oblique aerial photographs collected from the South Carolina/North Carolina border to Assateague Island, Virginia, February 18–19, 2016

Released February 28, 2017 14:15 EST

2017, Data Series 1029

Karen L. M. Morgan

The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in the vulnerability of the Nation's coasts to extreme storms. On February 18–19, 2016, the USGS conducted an oblique aerial photographic survey from the South Carolina/North Carolina border to Assateague Island, Virginia, aboard a Cessna 182 (aircraft) at an altitude of 500 feet (ft) and approximately 1,200 ft offshore. This mission was flown to collect baseline data for assessing incremental changes in the beach and nearshore area and can be used to assess future coastal change.

The photographs in this report document the state of the barrier islands and other coastal features at the time of the survey.

Preparing future fisheries professionals to make good decisions

Released February 28, 2017 00:00 EST

2017, Fisheries (41) 473-474

Michael E. Colvin, James T. Peterson

Future fisheries professionals will face decision-making challenges in an increasingly complex field of fisheries management. Though fisheries students are well trained in the use of the scientific method to understand the natural world, they are rarely exposed to structured decision making (SDM) as part of an undergraduate or graduate education. Specifically, SDM encourages users (e.g., students, managers) to think critically and communicate the problem and then identify specific, measurable objectives as they relate to the problem. Next, users must think critically and creatively about management alternatives that can be used to meet the objectives—there must be more than one alternative or there is no decision to be made. Lastly, the management alternatives are evaluated with regard to how likely they are to succeed in terms of multiple, possibly completing, objectives, such as how stakeholder groups value outcomes of management actions versus monetary cost. We believe that exposure to SDM and its elements is an important part of preparing future fisheries professional to meet the challenges they may face. These challenges include reduced budgets, the growth of potentially competing natural resource interest groups, and stakeholder desire to be involved in management decisions affecting public trust resources, just to name a few.

Defining snow drought and why it matters

Released February 28, 2017 00:00 EST

2017, EOS - Earth & Space Science News (98)

Adrian Harpold, Michael Dettinger, Seshadri Rajagopal

On 12 February, water resource managers at the Oroville Dam issued an evacuation warning that forced some 180,000 Californians to relocate to higher ground. The story of how conditions got to this point involves several factors, but two clearly stand out: the need to prevent water shortages during a record drought, followed by one of the wettest October–February periods in California history.

The situation at Oroville Dam highlights difficulties that many reservoir managers face in managing flood risks while simultaneously storing water to mitigate severe droughts and smaller snowpacks. Central to this difficulty is the idea of “snow drought,” a term that’s gaining traction in both scientific and lay literature.

Elevated bladder cancer in northern New England: The role of drinking water and arsenic

Released February 28, 2017 00:00 EST

2016, Journal of the National Cancer Institute (108)

Dalsu Baris, Richard Wadell, Laura Freeman, Molly Schwenn, Joanne Colt, Joseph Ayotte, Mary Ward, John Nuckols, Alan Schned, Brian Jackson, Castine Clerkin, Nathanial Rothman, Lee Moore, Anne Taylor, Gilpin Robinson, Monawar G. Hosain, Carla Armenti, Richard McCoy, Claudine Samanic, Robert Hoover, Joseph Fraumeni, Alison Johnson, Margaret Karagas, Debra Silverman

Background: Bladder cancer mortality rates have been elevated in northern New England for at least five decades. Incidence rates in Maine, New Hampshire, and Vermont are about 20% higher than the United States overall. We explored reasons for this excess, focusing on arsenic in drinking water from private wells, which are particularly prevalent in the region.

Methods: In a population-based case-control study in these three states, 1213 bladder cancer case patients and 1418 control subjects provided information on suspected risk factors. Log transformed arsenic concentrations were estimated by linear regression based on measurements in water samples from current and past homes. All statistical tests were two-sided.

Results: Bladder cancer risk increased with increasing water intake ( Ptrend = .003). This trend was statistically significant among participants with a history of private well use ( Ptrend = .01). Among private well users, this trend was apparent if well water was derived exclusively from shallow dug wells (which are vulnerable to contamination from manmade sources, Ptrend = .002) but not if well water was supplied only by deeper drilled wells ( Ptrend = .48). If dug wells were used pre-1960, when arsenical pesticides were widely used in the region, heavier water consumers (>2.2 L/day) had double the risk of light users (<1.1 L/day, Ptrend = .01). Among all participants, cumulative arsenic exposure from all water sources, lagged 40 years, yielded a positive risk gradient ( Ptrend = .004); among the highest-exposed participants (97.5th percentile), risk was twice that of the lowest-exposure quartile (odds ratio = 2.24, 95% confidence interval = 1.29 to 3.89).

Conclusions: Our findings support an association between low-to-moderate levels of arsenic in drinking water and bladder cancer risk in New England. In addition, historical consumption of water from private wells, particularly dug wells in an era when arsenical pesticides were widely used, was associated with increased bladder cancer risk and may have contributed to the New England excess.

An automated approach for mapping persistent ice and snow cover over high latitude regions

Released February 28, 2017 00:00 EST

2016, Remote Sensing (8)

David J. Selkowitz, Richard R. Forster

We developed an automated approach for mapping persistent ice and snow cover (glaciers and perennial snowfields) from Landsat TM and ETM+ data across a variety of topography, glacier types, and climatic conditions at high latitudes (above ~65°N). Our approach exploits all available Landsat scenes acquired during the late summer (1 August–15 September) over a multi-year period and employs an automated cloud masking algorithm optimized for snow and ice covered mountainous environments. Pixels from individual Landsat scenes were classified as snow/ice covered or snow/ice free based on the Normalized Difference Snow Index (NDSI), and pixels consistently identified as snow/ice covered over a five-year period were classified as persistent ice and snow cover. The same NDSI and ratio of snow/ice-covered days to total days thresholds applied consistently across eight study regions resulted in persistent ice and snow cover maps that agreed closely in most areas with glacier area mapped for the Randolph Glacier Inventory (RGI), with a mean accuracy (agreement with the RGI) of 0.96, a mean precision (user’s accuracy of the snow/ice cover class) of 0.92, a mean recall (producer’s accuracy of the snow/ice cover class) of 0.86, and a mean F-score (a measure that considers both precision and recall) of 0.88. We also compared results from our approach to glacier area mapped from high spatial resolution imagery at four study regions and found similar results. Accuracy was lowest in regions with substantial areas of debris-covered glacier ice, suggesting that manual editing would still be required in these regions to achieve reasonable results. The similarity of our results to those from the RGI as well as glacier area mapped from high spatial resolution imagery suggests it should be possible to apply this approach across large regions to produce updated 30-m resolution maps of persistent ice and snow cover. In the short term, automated PISC maps can be used to rapidly identify areas where substantial changes in glacier area have occurred since the most recent conventional glacier inventories, highlighting areas where updated inventories are most urgently needed. From a longer term perspective, the automated production of PISC maps represents an important step toward fully automated glacier extent monitoring using Landsat or similar sensors.

Fluid-faulting evolution in high definition: Connecting fault structure and frequency-magnitude variations during the 2014 Long Valley Caldera, California earthquake swarm

Released February 28, 2017 00:00 EST

2016, Journal of Geophysical Research (212) 1776-1795

David R. Shelly, William L. Ellsworth, David P. Hill

An extended earthquake swarm occurred beneath southeastern Long Valley Caldera between May and November 2014, culminating in three magnitude 3.5 earthquakes and 1145 cataloged events on 26 September alone. The swarm produced the most prolific seismicity in the caldera since a major unrest episode in 1997-1998. To gain insight into the physics controlling swarm evolution, we used large-scale cross-correlation between waveforms of cataloged earthquakes and continuous data, producing precise locations for 8494 events, more than 2.5 times the routine catalog. We also estimated magnitudes for 18,634 events (~5.5 times the routine catalog), using a principal component fit to measure waveform amplitudes relative to cataloged events. This expanded and relocated catalog reveals multiple episodes of pronounced hypocenter expansion and migration on a collection of neighboring faults. Given the rapid migration and alignment of hypocenters on narrow faults, we infer that activity was initiated and sustained by an evolving fluid pressure transient with a low-viscosity fluid, likely composed primarily of water and CO2 exsolved from underlying magma. Although both updip and downdip migration were observed within the swarm, downdip activity ceased shortly after activation, while updip activity persisted for weeks at moderate levels. Strongly migrating, single-fault episodes within the larger swarm exhibited a higher proportion of larger earthquakes (lower Gutenberg-Richter b value), which may have been facilitated by fluid pressure confined in two dimensions within the fault zone. In contrast, the later swarm activity occurred on an increasingly diffuse collection of smaller faults, with a much higher b value.

Collapse risk of buildings in the Pacific Northwest region due to subduction earthquakes

Released February 28, 2017 00:00 EST

2015, Earthquake Spectra (31) 2087-2115

Meera Raghunandan, Abbie B Liel, Nicolas Luco

Subduction earthquakes similar to the 2011 Japan and 2010 Chile events will occur in the future in the Cascadia subduction zone in the Pacific Northwest. In this paper, nonlinear dynamic analyses are carried out on 24 buildings designed according to outdated and modern building codes for the cities of Seattle, Washington, and Portland, Oregon. The results indicate that the median collapse capacity of the ductile (post-1970) buildings is approximately 40% less when subjected to ground motions from subduction, as compared to crustal earthquakes. Buildings are more susceptible to earthquake-induced collapse when shaken by subduction records (as compared to crustal records of the same intensity) because the subduction motions tend to be longer in duration due to their larger magnitude and the greater source-to-site distance. As a result, subduction earthquakes are shown to contribute to the majority of the collapse risk of the buildings analyzed.

Dating base flow in streams using dissolved gases and diurnal temperature changes

Released February 28, 2017 00:00 EST

2015, Water Resources Research (51) 9790-9803

Ward E. Sanford, Gerolamo C. Casile, Karl B. Haase

A method is presented for using dissolved CFCs or SF6 to estimate the apparent age of stream base flow by indirectly estimating the mean concentration of the tracer in the inflowing groundwater. The mean value is estimated simultaneously with the mean residence times of the gas and water in the stream by sampling the stream for one or both age tracers, along with dissolved nitrogen and argon at a single location over a period of approximately 12–14 h. The data are fitted to an equation representing the temporal in-stream gas exchange as it responds to the diurnal temperature fluctuation. The efficacy of the method is demonstrated by collecting and analyzing samples at six different stream locations across parts of northern Virginia, USA. The studied streams drain watersheds with areas of between 2 and 122 km2 during periods when the diurnal stream temperature ranged between 2 and 5°C. The method has the advantage of estimating the mean groundwater residence time of discharge from the watershed to the stream without the need for the collection of groundwater infiltrating to streambeds or local groundwater sampled from shallow observation wells near the stream.

Trends in the quality of water in New Jersey streams, water years 1971–2011

Released February 27, 2017 10:00 EST

2017, Scientific Investigations Report 2016-5176

R. Edward Hickman, Robert M. Hirsch

In a study conducted by the U.S. Geological Survey in cooperation with the New Jersey Department of Environmental Protection and the Delaware River Basin Commission, trend tests were conducted on selected water-quality characteristics measured at stations on streams in New Jersey during selected periods over water years 1971‒2011. Tests were conducted on 3 nutrients (total nitrogen, filtered nitrate plus nitrite, and total phosphorus) at 28 water-quality stations. At 4 of these stations, tests were also conducted on 3 measures of major ions (specific conductance, filtered chloride, and total dissolved solids).

Two methods were used to identify trends—Weighted Regressions on Time, Discharge, and Season (WRTDS) models and seasonal rank-sum tests. For this report, the use of WRTDS models included the use of the WRTDS Bootstrap Test (WBT). WRTDS models identified trends in flow-normalized annual concentrations and flow-normalized annual fluxes over water years 1980‒2011 and 2000‒11 for each nutrient, filtered chloride, and total dissolved solids. WRTDS models were developed for each nutrient at the 20 or 21 stations at which streamflow was measured or estimated. Trends in nutrient concentration were reported for these stations; trends in nutrient fluxes were reported only for 15–17 of these stations.

The results of WRTDS models for water years 1980‒2011 identified more stations with downward trends in concentrations of either total nitrogen or total phosphorus than upward trends. For total nitrogen, there were downward trends at 9 stations and an upward trend at 1 station. For total phosphorus, there were downward trends at 8 stations and an upward trend at 1 station. For filtered nitrate plus nitrite, there were downward trends at 6 stations and upward trends at 6 stations. The result of the trend test in flux for a selected nutrient at a selected station (downward trend, no trend, or upward trend) usually matched the trend result in concentration.

Seasonal rank-sum tests, the second method used, identified step trends in water-quality measured in different decades—1970s, 1980s, 1990s, and 2000s. Tests were conducted on all nutrients at 28 stations and on all measures of major ions at the 4 selected stations. Results of seasonal rank-sum tests between the 1980s and the 2000s identified more stations with downward trends in concentrations of total nitrogen (14) than stations with upward trends (2) and more stations with downward trends in concentrations of total phosphorus (18) than stations with upward trends (1).

A combined dataset of trend results for concentrations over water years 1980‒2011 was created from the results of the two tests for the period. Results of WRTDS models were included in this combined dataset, if available. Otherwise, the results of the seasonal rank-sum tests between water-quality characteristics measured in the 1980s and 2000s were included.

Trend results over water years 1980‒2011 in the combined dataset show that few of the 28 stations had upward trends in concentrations of either total nitrogen or total phosphorus. There were only 2 stations with upward trends in total nitrogen concentration and 1 station with an upward trend in total phosphorus concentration. Results for filtered nitrate plus nitrite show about the same number of stations with upward trends (9) as stations with downward trends (7). Results for all measures of major ions show upward trends at the four stations tested.

Water-quality sampling plan for evaluating the distribution of bigheaded carps in the Illinois Waterway

Released February 27, 2017 08:45 EST

2017, Open-File Report 2017-1019

James J. Duncker, Paul J. Terrio

The two nonnative invasive bigheaded carp species (bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix) that were accidentally released in the 1970s have spread widely into the rivers and waterways of the Mississippi River Basin. First detected in the lower reaches of the Illinois Waterway (IWW, the combined Illinois River-Des Plaines River-Chicago Area Waterway System) in the 1990s, bighead and silver carps moved quickly upstream, approaching the Chicago Area Waterway System. The potential of substantial negative ecological and economic impact to the Great Lakes from the presence of these species is a concern. However, since 2006, the population front of bigheaded carps has remained in the vicinity of Joliet, Illinois, near river mile 278. This reach of the IWW is characterized by stark changes in habitat, water quality, and food resources as the waterway transitions from a primarily agricultural landscape to a metropolitan and industrial canal system. This report describes a 2015 plan for sampling the IWW to establish water-quality conditions that might be contributing to the apparent stalling of the population front of bigheaded carps in this reach. A detailed description of the study plan, Lagrangian-style sampling approach, selected analytes, sampling methods and protocols are provided. Hydrographs from streamflow-gaging stations show IWW conditions during the 2015 sampling runs.

Nonnative trout invasions combined with climate change threaten persistence of isolated cutthroat trout populations in the southern Rocky Mountains

Released February 27, 2017 00:00 EST

2017, North American Journal of Fisheries Management (37) 314-325

James J. Roberts, Kurt D. Fausch, Mevin B. Hooten, Douglas P. Peterson

Effective conservation of Cutthroat Trout Oncorhynchus clarkii lineages native to the Rocky Mountains will require estimating effects of multiple stressors and directing management toward the most important ones. Recent analyses have focused on the direct and indirect effects of a changing climate on contemporary ranges, which are much reduced from historic ranges owing to past habitat loss and nonnative trout invasions. However, nonnative trout continue to invade Cutthroat Trout populations in the southern Rocky Mountains. Despite management to isolate and protect these native populations, nonnatives still surmount barriers or are illegally stocked above them. We used data on the incidence of invasions by nonnative Brook Trout (BT) Salvelinus fontinalis and the rate of their invasion upstream to simulate effects on a set of 309 conservation populations of Colorado River Cutthroat Trout (CRCT) O. c. pleuriticus isolated in headwater stream fragments. A previously developed Bayesian network model was used to compare direct and indirect effects of climate change (CC) alone on population persistence versus the added effects of BT invasions. Although CC alone is predicted to extirpate only one CRCT population by 2080, BT invasions and CC together are predicted to completely extirpate 122 populations (39% of the total) if managers do not intervene. Another 113 populations (37%) will be at risk of extirpation after CC and invasions, primarily owing to stochastic risks in short stream fragments that are similar under CC alone. Overall, invasions and CC will reduce the number of stream fragments that are long enough to buffer CRCT populations against negative genetic consequences and stochastic disturbances by 48, a decrease of 38% compared to CC alone. High priorities are (1) research to estimate how CC and human factors alter the incidence and rate of BT invasions and (2) management to prevent new illegal introductions, repair inadequate barriers, and monitor and address new invasions.

Geochemistry and hydrology of perched groundwater springs: assessing elevated uranium concentrations at Pigeon Spring relative to nearby Pigeon Mine, Arizona (USA)

Released February 27, 2017 00:00 EST

2017, Hydrogeology Journal (25) 539-556

Kimberly R. Beisner, Nicholas Paretti, Fred Tillman, David L. Naftz, Donald Bills, Katie Walton-Day, Tanya J. Gallegos

The processes that affect water chemistry as the water flows from recharge areas through breccia-pipe uranium deposits in the Grand Canyon region of the southwestern United States are not well understood. Pigeon Spring had elevated uranium in 1982 (44 μg/L), compared to other perched springs (2.7–18 μg/L), prior to mining operations at the nearby Pigeon Mine. Perched groundwater springs in an area around the Pigeon Mine were sampled between 2009 and 2015 and compared with material from the Pigeon Mine to better understand the geochemistry and hydrology of the area. Two general groups of perched groundwater springs were identified from this study; one group is characterized by calcium sulfate type water, low uranium activity ratio 234U/238U (UAR) values, and a mixture of water with some component of modern water, and the other group by calcium-magnesium sulfate type water, higher UAR values, and radiocarbon ages indicating recharge on the order of several thousand years ago. Multivariate statistical principal components analysis of Pigeon Mine and spring samples indicate Cu, Pb, As, Mn, and Cd concentrations distinguished mining-related leachates from perched groundwater springs. The groundwater potentiometric surface indicates that perched groundwater at Pigeon Mine would likely flow toward the northwest away from Pigeon Spring. The geochemical analysis of the water, sediment and rock samples collected from the Snake Gulch area indicate that the elevated uranium at Pigeon Spring is likely related to a natural source of uranium upgradient from the spring and not likely related to the Pigeon Mine.

A manual to identify sources of fluvial sediment

Released February 27, 2017 00:00 EST

2017, Report

Allen Gellis, Faith Fitzpatrick, Joseph Schubauer-Berigan

Sediment is an important pollutant of concern that can degrade and alter aquatic habitat. A sediment budget is an accounting of the sources, storage, and export of sediment over a defined spatial and temporal scale. This manual focuses on field approaches to estimate a sediment budget. We also highlight the sediment fingerprinting approach to attribute sediment to different watershed sources. Determining the sources and sinks of sediment is important in developing strategies to reduce sediment loads to water bodies impaired by sediment. Therefore, this manual can be used when developing a sediment TMDL requiring identification of sediment sources.

The manual takes the user through the seven necessary steps to construct a sediment budget:

  1. Decision-making for watershed scale and time period of interest
  2. Familiarization with the watershed by conducting a literature review, compiling background information and maps relevant to study questions, conducting a reconnaissance of the watershed
  3. Developing partnerships with landowners and jurisdictions
  4. Characterization of watershed geomorphic setting
  5. Development of a sediment budget design
  6. Data collection
  7. Interpretation and construction of the sediment budget
  8. Generating products (maps, reports, and presentations) to communicate findings.

Sediment budget construction begins with examining the question(s) being asked and whether a sediment budget is necessary to answer these question(s). If undertaking a sediment budget analysis is a viable option, the next step is to define the spatial scale of the watershed and the time scale needed to answer the question(s). Of course, we understand that monetary constraints play a big role in any decision.

Early in the sediment budget development process, we suggest getting to know your watershed by conducting a reconnaissance and meeting with local stakeholders. The reconnaissance aids in understanding the geomorphic setting of the watershed and potential sources of sediment. Identifying the potential sediment sources early in the design of the sediment budget will help later in deciding which tools are necessary to monitor erosion and/or deposition at these sources. Tools can range from rapid inventories to estimate the sediment budget or quantifying sediment erosion, deposition, and export through more rigorous field monitoring. In either approach, data are gathered and erosion and deposition calculations are determined and compared to the sediment export with a description of the error uncertainty. Findings are presented to local stakeholders and management officials.

Sediment fingerprinting is a technique that apportions the sources of fine-grained sediment in a watershed using tracers or fingerprints. Due to different geologic and anthropogenic histories, the chemical and physical properties of sediment in a watershed may vary and often represent a unique signature (or fingerprint) for each source within the watershed. Fluvial sediment samples (the target sediment) are also collected and exhibit a composite of the source properties that can be apportioned through various statistical techniques. Using an unmixing-model and error analysis, the final apportioned sediment is determined.

Application of genetics and genomics to wildlife epidemiology

Released February 27, 2017 00:00 EST

2016, Journal of Wildlife Management (80) 593-608

Julie A. Blanchong, Stacie J. Robinson, Michael D. Samuel, Jeffery T Foster

Wildlife diseases can have significant impacts on wildlife conservation and management. Many of the pathogens that affect wildlife also have important implications for domestic animal and human health. However, management interventions to prevent or control wildlife disease are hampered by uncertainties about the complex interactions between pathogens and free-ranging wildlife. We often lack crucial knowledge about host ecology, pathogen characteristics, and host–pathogen dynamics. The purpose of this review is to familiarize wildlife biologists and managers with the application of genetic and genomic methodologies for investigating pathogen and host biology to better understand and manage wildlife diseases. The genesis of this review was a symposium at the 2013 annual Wildlife Society Conference. We reviewed the scientific literature and used our personal experiences to identify studies that illustrate the application of genetic and genomic methods to advance our understanding of wildlife epidemiology, focusing on recent research, new techniques, and innovative approaches. Using examples from a variety of pathogen types and a broad array of vertebrate taxa, we describe how genetics and genomics can provide tools to detect and characterize pathogens, uncover routes of disease transmission and spread, shed light on the ways that disease susceptibility is influenced by both host and pathogen attributes, and elucidate the impacts of disease on wildlife populations. Genetic and increasingly genomic methodologies will continue to contribute important insights into pathogen and host biology that will aid efforts to assess and mitigate the impacts of wildlife diseases on global health and conservation of biodiversity.

Nature vs. nurture: Evidence for social learning of conflict behaviour in grizzly bears

Released February 27, 2017 00:00 EST

2016, PLoS ONE (11)

Andrea T. Morehouse, Tabitha A. Graves, Nathaniel Mikle, Mark S. Boyce

The propensity for a grizzly bear to develop conflict behaviours might be a result of social learning between mothers and cubs, genetic inheritance, or both learning and inheritance. Using non-invasive genetic sampling, we collected grizzly bear hair samples during 2011–2014 across southwestern Alberta, Canada. We targeted private agricultural lands for hair samples at grizzly bear incident sites, defining an incident as an occurrence in which the grizzly bear caused property damage, obtained anthropogenic food, or killed or attempted to kill livestock or pets. We genotyped 213 unique grizzly bears (118 M, 95 F) at 24 microsatellite loci, plus the amelogenin marker for sex. We used the program COLONY to assign parentage. We evaluated 76 mother-offspring relationships and 119 father-offspring relationships. We compared the frequency of problem and non-problem offspring from problem and non-problem parents, excluding dependent offspring from our analysis. Our results support the social learning hypothesis, but not the genetic inheritance hypothesis. Offspring of problem mothers are more likely to be involved in conflict behaviours, while offspring from non-problem mothers are not likely to be involved in incidents or human-bear conflicts themselves (Barnard’s test, p = 0.05, 62.5% of offspring from problem mothers were problem bears). There was no evidence that offspring are more likely to be involved in conflict behaviour if their fathers had been problem bears (Barnard’s test, p = 0.92, 29.6% of offspring from problem fathers were problem bears). For the mother-offspring relationships evaluated, 30.3% of offspring were identified as problem bears independent of their mother’s conflict status. Similarly, 28.6% of offspring were identified as problem bears independent of their father’s conflict status. Proactive mitigation to prevent female bears from becoming problem individuals likely will help prevent the perpetuation of conflicts through social learning.

Relations between altered stramflow variability and fish assemblages in Eastern USA streams

Released February 27, 2017 00:00 EST

2012, River Research and Applications (28) 1359-1368

Michael R. Meador, Daren M. Carlisle

Although altered streamflow has been implicated as a major factor affecting fish assemblages, understanding the extent of streamflow alteration has required quantifying attributes of the natural flow regime. We used predictive models to quantify deviation from expected natural streamflow variability for streams in the eastern USA. Sites with >25% change in mean daily streamflow variability compared with what would be expected in a minimally disturbed environment were defined as having altered streamflow variability, based on the 10th and 90th percentiles of the distribution of streamflow variability at 1279 hydrological reference sites. We also used predictive models to assess fish assemblage condition and native species loss based on the proportion of expected native fish species that were observed. Of the 97 sites, 49 (50.5%) were classified as altered with reduced streamflow variability, whereas no sites had increased streamflow variability. Reduced streamflow variability was related to a 35% loss in native fish species, on average, and a >50% loss of species with a preference for riffle habitats. Conditional probability analysis indicated that the probability of fish assemblage impairment increased as the severity of altered streamflow variability increased. Reservoir storage capacity and wastewater discharges were important predictors of reduced streamflow variability as revealed by random forest analysis. Management and conservation of streams will require careful consideration of natural streamflow variation and potential factors contributing to altered streamflow within the entire watershed to limit the loss of critical stream habitats and fish species uniquely adapted to live in those habitats.