Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Publications recently added to the Pubs Warehouse

(500 records max)
The association of geochemical anomalies with a negative gravity anomaly in the Chief Mountain-Soda Creek area, Clear Creek County, Colorado

Released July 05, 2022 10:37 EST

1974, Journal of Research of the U.S. Geological Survey (2) 581-592

G. C. Curtin, H. D. King

Geochemical studies in the Chief Mountain Soda Creek area, Clear Creek County, Colo., show that anomalously high amounts of Au, Ag, Pb, Zn, Cd, and Bi in mull ash, and Cu and Hg in soil, correspond to a negative gravity anomaly in the Front Range mineral belt. The correspondence of the geochemical anomalies to the negative gravity anomaly suggests the presence of altered and mineralized rock and a Tertiary intrusive body at depth. This gravity anomaly and other similar gravity anomalies in the Front Range mineral belt merit further investigation for possible ore deposits.

A model of the spatiotemporal dynamics of soil carbon following coastal wetland loss applied to a Louisiana salt marsh in the Mississippi River Deltaic Plain

Released July 04, 2022 10:04 EST

2022, Journal of Geophysical Research: Biogeosciences (127)

Donald R. Schoolmaster Jr., Camille Stagg, Courtney Creamer, Claudia Laurenzano, Eric Ward, Mark Waldrop, Melissa M. Baustian, Tiong Aw, Sergio Merino, Rachel Katherine Villani, Laura Scott

The potential for carbon sequestration in coastal wetlands is high due to protection of carbon (C) in flooded soils. However, excessive flooding can result in the conversion of the vegetated wetland to open water. This transition results in the loss of wetland habitat in addition to the potential loss of soil carbon. Thus, in areas experiencing rapid wetland submergence, such as the Mississippi River Delta, coastal wetlands could become a significant source of carbon emissions if land loss is not mitigated. To accurately assess the capacity of wetlands to store (or emit) carbon in dynamic environments, it is critical to understand the fate of soil carbon following the transition from vegetated wetland to open water. We developed a simple soil carbon model representing soil depths to 1 m using the data collected from a Louisiana coastal salt marsh in the Mississippi River Deltaic Plain to predict soil carbon density and stock following the transition from a vegetated salt marsh to an open water pond. While immediate effects of ponding on the distribution of carbon within the 1-m soil profile were apparent, there were no effects of ponding on the overall, integrated, carbon stocks 14 years, following wetland submergence. Rather, the model predicts that soil carbon losses in the first meter will be realized over long periods of time (∼200 years) due to changes in the source of carbon (biomass vs. mineral sediment) with minimal losses through mineralization.

Mentoring is more than a mentor

Released July 04, 2022 09:59 EST

2022, Frontiers in Ecology and the Environment (20) 271-271

Courtney G. Collins, Michala Lee Phillips, Kendall Beals, Lydia Baliey, Joy O'Brien, Ishwora Dhungana, Sierra Jech

Recent work has highlighted the substantial positive impact of multi-dimensional mentoring, particularly a mentoring network, in one’s professional development and overall well-being (SAGE Open 2017; doi.org/10.1177/2158244017710288) (Nat Comm 2022; doi.org/10.1038/s41467-022-28667-0). The Women in Soil Ecology (WiSE) network (https://womeninsoilecology.github.io) was born out of a desire to develop mentoring relationships between women from different institutions and career stages – to fill the gaps in traditional faculty–graduate student advising relationships. These gaps included the need for advice and role models in dealing with issues such as harassment and safety in the field and at conferences, work–life balance, navigating family and childcare responsibilities, equal pay and representation, and being a woman in the male-dominated field of soil science (Soil Sci Soc Am J 2019; doi.org/10.2136/sssaj2019.03.0085). Four years and an ongoing pandemic later, our network has grown into much more than we initially envisioned and now connects women with a passion for soil ecology from across the globe.

Genome-wide genetic diversity may help identify fine-scale genetic structure among lake whitefish spawning groups in Lake Erie

Released July 04, 2022 09:43 EST

2022, Journal of Great Lakes Research

Peter T. Euclide, Joseph Schmitt, Richard Kraus, Andy Cook, Jim Markham

In Lake Erie, lake whitefish Coregonus clupeaformis supported lucrative fisheries before populations were decimated by overfishing and water quality degradation. In recent years, there has been a renewed interest in lake whitefish and management of the fishery they support. Lake whitefish spawn on several reefs throughout Lake Erie, but the relative recruitment dynamics and contributions of spawning groups to the fishery are not well understood. Modern high-throughput sequencing approaches offer new opportunities to census population diversity and to identify subtle differences among closely related populations. We used high-throughput sequencing data to evaluate the genetic structure and diversity of lake whitefish collected opportunistically across broad spatial scales in Lake Erie. Using RAD-capture (Rapture), we sequenced and genotyped individuals (N = 88) from the west, central, and east basin of Lake Erie at 120,268 single nucleotide polymorphisms (SNPs). Lake whitefish from Niagara and Crib Reefs (west basin) diverged from the three collections. Interestingly, these were the only lake whitefish collected during the act of spawning (late November), and all other fish were collected pre-spawn (August-early November). These results suggest that some lake whitefish spawning reefs may be reproductively isolated, though definition of these groups into stocks will require more intentional sampling during the act of spawning.

A structured decision-making framework for managing cyanobacterial harmful algal blooms in New York State parks

Released July 01, 2022 13:25 EST

2022, Scientific Investigations Report 2022-5053

Jennifer L. Graham, Gabriella M. Cebada Mora, Rebecca M. Gorney, Lianne C. Ball, Claudia Mengelt, Michael C. Runge

Cyanobacteria are increasingly a global water-quality concern because of the potential for these organisms to develop into potentially harmful blooms that affect ecological, economic, and public health. Cyanobacterial harmful algal blooms (CyanoHABs) can lead to a decrease in water quality and affect many of the recreational and ecological benefits of parks that include lakes. The New York State Office of Parks, Recreation and Historic Preservation (OPRHP) is a State agency within the New York State Executive Department charged with the operation of State parks and historic sites. Many New York State parks include lakes or other freshwater bodies, which can be susceptible to CyanoHABs. The OPRHP faces difficult decisions regarding prevention of and response to CyanoHABs. The U.S. Geological Survey partnered with the OPRHP and the New York State Department of Environmental Conservation to develop a structured decision-making template for managing CyanoHABs in OPRHP parks. Two parks, Moreau Lake State Park and Rockland Lake State Park, served as case studies to motivate and test the template. This report describes how the principles of structured decision making can be used to navigate the challenges associated with managing CyanoHABs in OPRHP parks. Management objectives and strategies for CyanoHABs in parks are described, strategies to evaluate consequences and manage tradeoffs are discussed, and potential challenges to the implementation of preferred alternatives are considered. General guidance is provided so the OPRHP can undertake the structured decision-making process for CyanoHABs in any of its parks. In addition, this report represents the first effort to create a strategy for applying decision analysis tools to the complex natural resource challenge of CyanoHAB mitigation and management. The case studies and template are intended to serve as an example that natural resource managers faced with CyanoHABs challenges can use to inform their decision-making processes.

Continental shelves as detrital mixers: U-Pb and Lu-Hf detrital zircon provenance of the Pleistocene–Holocene Bering Sea and its margins

Released July 01, 2022 08:20 EST

2022, The Depositional Record

Matthew A. Malkowski, Samuel A. Johnstone, Glenn R. Sharman, Colin J. White, Daniel Scheirer, Ginger Barth

Continental shelves serve as critical transfer zones in sediment-routing systems, linking the terrestrial erosional and deep-water depositional domains. The degree to which clastic sediment is mixed and homogenized during transfer across broad shelves has important implications for understanding deep-sea detrital records. Wide continental shelves are thought to act as capacitors characterized by transient sediment storage during sea level rise and sediment remobilization during sea level fall. This study attempts to test the hypothesis that sea level lowstand yields more efficient and direct sediment transfer from fluvial sources to deep-sea sinks compared to highstand when sediment is sequestered and mixed on the shelf. We test this by evaluating U-Pb and Lu-Hf detrital zircon provenance trends along the vast Bering Sea shelf and deep-marine Beringian continental margin. We present 5884 U-Pb ages and 402 Lu-Hf analyses from 30 samples to characterize the provenance of modern to Pleistocene sediment across the Bering Sea region. We used both forward and inverse numerical mixture modeling to estimate the abundance of distinct fluvial sources in shelfal and deep-water deposits. These results demonstrate that sediment in the Bering Sea is derived from a mixture of regional fluvial sources, but that the Yukon River is the primary detrital source for sediment throughout the region. Although Yukon River signatures are abundant in all basin samples, the relative proportions of Yukon vs other sources vary spatially across the shelf. A comparison of Holocene and surficial sediment with Pleistocene deposits shows that sediment across the shelf and in the deep-sea remains well-mixed between climate states. Thus, detrital provenance signatures in deep-marine deposits outward of broad transfer zones are likely to represent mixtures of fluvial sources regardless of sea level.

Characterization of and temporal changes in groundwater quality of the Upper Black Squirrel Creek Basin, El Paso County, Colorado, 2018–20

Released June 30, 2022 16:00 EST

2022, Scientific Investigations Report 2022-5061

Zachary D. Kisfalusi, Nancy J. Bauch, Carleton R. Bern

In 2018–20, the U.S. Geological Survey, in cooperation with Upper Black Squirrel Creek Ground Water Management District, sampled 48 wells for Phase III of a multiphase plan investigating groundwater quality in the alluvial aquifer of the Upper Black Squirrel Creek Basin (UBSB), El Paso County, Colorado. Results for samples collected from October to December each year were used to assess spatial and temporal changes in groundwater quality and to differentiate sources of nitrate. Groundwater was predominantly classified as mixed-cation and mixed-anion water type in the aquifer, with variable chemistry along the periphery. Concentrations of constituents in groundwater were generally less than regulatory standards, except for nitrate in four wells. Isotopes of nitrogen and oxygen in nitrate identified four different potential sources or processes affecting nitrate in the alluvial aquifer: naturally occurring nitrate from soils, nitrate from animal and (or) human waste, and an unknown source, along with evidence of denitrification. Pharmaceutical compounds and personal-care products were detected in seven wells, with three wells having multiple detections. Stable isotopes of water indicated variability in seasonality of recharge throughout the UBSB alluvial aquifer. Nitrate concentrations from the 1984 study and the 1996 study were compared to the more recent concentrations in the 2013 study and the 2018–20 study. The northern one-third of the UBSB alluvial aquifer had a statistically significant increase in nitrate concentration from the 2013 study to the 2018–20 study, but no change was shown from the 1984 study to the 1996 study. The opposite was found true for the southern two-thirds of the UBSB alluvial aquifer with no statistically significant difference in nitrate concentration from the 2013 study to the 2018–20 study. Analysis of temporal changes indicated an increase in median and maximum nitrate concentrations from the 2013 study to the 2018–20 study throughout the UBSB alluvial aquifer. Continued sampling of wells in the UBSB would be beneficial to better determine temporal changes in groundwater quality, characterize human effects on water quality, and understand characteristics of the alluvial aquifer pertaining to sustainability of the resource.

West Virginia and Landsat

Released June 30, 2022 12:49 EST

2022, Fact Sheet 2022-3044

U.S. Geological Survey

Many may recall “Take Me Home, Country Roads,” made famous by John Denver, leads with the lyric “almost heaven, West Virginia, Blue Ridge Mountains, Shenandoah River.” The descriptors are apt. Nicknamed the “Mountain State,” West Virginia inspires thoughts of coal mining or logging in the Appalachian Mountains and valleys, or the leaping trout in the winding waters of Shenandoah National Park.

West Virginia is second only to Wyoming in coal production nationwide. Its mines produced more than 67 million tons of coal in 2020. Logging pumped about $3.4 billion into the State’s economy in 2019; tourist spending added another $4.6 billion.

Those industries are key for West Virginia, but agriculture and fisheries also play a role in the State's economic fortunes. Peaches and apples are major drivers of food production, as are beef and poultry. Trout, meanwhile, are caught and sold commercially, and are stocked throughout the State's rivers for local and visiting anglers.

Scientists, land managers, and others use imagery from the U.S. Geological Survey Landsat satellite program's deep historical archive to better understand and manage West Virginia’s storied forests, fields, mountains, and foothills.

Microplastic particles in dust-on-snow, Upper Colorado River Basin, Colorado Rocky Mountains, 2013–16

Released June 29, 2022 18:50 EST

2022, Open-File Report 2022-1061

Richard L. Reynolds, Harland L. Goldstein, Raymond F. Kokaly, Jeff Derry

Atmospheric dust deposited to snow cover (dust-on-snow) diminishes snow-surface albedo (SSA) to result in early onset and accelerated rate of melting, effects that challenge management of downstream water resources. During ongoing investigations to identify the light-energy absorbing dust particles most responsible for diminished SSA in the Upper Colorado River Basin of the Colorado Rocky Mountains, we found microplastic particles, which are defined as those less than 5 millimeters in any dimension. In each of the 38 samples that represented the last remaining dust layer during melt seasons of 2013–16, microplastics were identified by size, shape, and color, and their relative amounts were visually estimated using stereomicroscopy. Considering the remote, high-elevation settings of the sample sites, the microplastic particles must have been deposited from the atmosphere. The possible role of microplastics for diminishing SSA of snow cover in the Upper Colorado River Basin may be linked to the solar-energy absorptive properties of polymers and is the subject of ongoing investigation.

U.S. Geological Survey response to Hurricane Maria flooding in Puerto Rico and characterization of peak streamflows observed September 20–22, 2017

Released June 29, 2022 11:51 EST

2022, Scientific Investigations Report 2022-5040

Julieta M. Gómez-Fragoso, Mark Smith, Marilyn Santiago

Hurricane Maria struck the island of Puerto Rico on September 20, 2017, as a Category 4 storm. The hurricane traversed the island from southeast to northwest and produced recorded 48-hour rainfall totals of up to 30.01 inches. Estimates of the human death toll range from 2,975 to 4,645, possibly more.

The U.S. Geological Survey (USGS) hydrologic monitoring network sustained substantial wind and flood damage during the hurricane. Eighty-five of the 300 hydrologic monitoring stations operating in Puerto Rico and the U.S. Virgin Islands prior to the passage of Hurricane Maria were destroyed or damaged. During the weeks and months after the hurricane, USGS field crews in Puerto Rico prioritized repair of the hydrologic monitoring network and collected hydrologic information to characterize the magnitude of observed peak streamflows at 20 streamgage and to develop new theoretical stage-streamflow relations for 58 streamgages where stream channels were substantially altered; the theoretical stage-streamflow relations were used to estimate Hurricane Maria peak streamflows for 39 of those sites. As part of a pilot program, USGS field crews installed continuous slope-area monitoring equipment at two remote streamgages to automate the collection of high-streamflow stage data.

Hurricane Maria peak streamflows and rankings were determined for 73 USGS streamgages in Puerto Rico. New rank 1 period-of-record peak streamflows occurred at 28 sites, rank 2 period-of-record peak streamflows occurred at 17 sites, and rank 3 period-of-record peak streamflows occurred at 9 sites; period-of-record peak streamflows at the remaining 19 sites either ranked from 4th to 20th or were not ranked. Annual exceedance probabilities for 53 unregulated peak streamflows ranged from greater than 50.0 percent (recurrence interval of less than 2 years) to 0.3 percent (recurrence interval of 333 years), with the majority (28 of 53) in the range of 10.0–2.1 percent (recurrence intervals of 10–48 years).

A comparison of period-of-record ranks for the largest flood events that have occurred in Puerto Rico since the 1960s indicated that Hurricane Maria produced more record peak streamflows than either Hurricane Hortense in 1996 or Hurricane Georges in 1998. Limited pre-1960s hydrologic data preclude quantitative comparison with earlier storms.

As part of this study, a maximum peak-streamflow envelope curve for Puerto Rico was developed using historical peak-streamflow information available through 2017. Other post-Hurricane Maria USGS activities summarized in this report include (1) Global Navigation Satellite System surveys at all stations in the USGS hydrologic monitoring network, used to tie the network to the Puerto Rico Vertical Datum of 2002; and (2) telemetered monitoring of the Lago Guajataca Dam in northwestern Puerto Rico, which was damaged and at risk of failure from October to December 2017.

Stratigraphic relations of the Bolsa Quartzite, Vekol Mountains, Pinal County, Arizona

Released June 29, 2022 09:04 EST

1974, Journal of Research of the U.S. Geological Survey (2) 143-146

M. A. Chaffee

A quartzite unit occurring between the rocks of the Precambrian Apache Group and those of the Cambrian Abrigo Formation in the Vekol Mountains, Final County, Ariz., has been called both Troy Quartzite (Precambrian) and Bolsa(?) Quartzite (Cambrian). Regional and local geologic relationships indicate that this intervening unit is definitely the Bolsa Quartzite. The Bolsa ranges in thickness from at least 200 ft at several localities in the Vekol Mountains to 0 ft over a positive area underlain by Precambrian diabase which has intruded the Apache Group. Previous observations that the diabase intruded the quartzite unit (thereby making this quartzite unit the Troy Quartzite) have been reinterpreted; all nonfaulted exposures of the basal contact of the quartzite unit show sedimentary relationships. No evidence was found to suggest that the Troy Quartzite was ever deposited in the Vekol Mountains.

Hydrogeology and simulation of groundwater flow in the Lucerne Valley groundwater basin, California

Released June 28, 2022 14:08 EST

2022, Scientific Investigations Report 2022-5048

Christina Stamos-Pfeiffer, Joshua D. Larsen, Robert E. Powell, Jonathan C. Matti, Peter Martin

The Lucerne Valley is in the southwestern part of the Mojave Desert and is about 75 miles northeast of Los Angeles, California. The Lucerne Valley groundwater basin encompasses about 230 square miles and is separated from the Upper Mojave Valley groundwater basin by splays of the Helendale Fault. Since its settlement, groundwater has been the primary source of water for agricultural, industrial, municipal, and domestic uses. Groundwater withdrawal from pumping has exceeded the amount of water recharged to the basin, causing groundwater declines of more than 100 feet between 1917 and 2016 in the center of the basin. The continued withdrawal has resulted in an increase in pumping costs, reduced well efficiency, and land subsidence near Lucerne Lake. Although the volume of pumping has declined in recent years, there is concern that new agricultural growth and limits on imported water will continue to strain the sustainability of the groundwater system.

To address these concerns, the U.S. Geological Survey entered into a cooperative agreement with the Mojave Water Agency to develop a better understanding of the Lucerne Valley hydrogeologic system and provide tools to help evaluate and manage the effects of future development in the Lucerne Valley. The objectives of this study were to (1) improve the understanding of the aquifer system, (2) improve the understanding of subsidence in the basin, and (3) incorporate the understanding into a groundwater-flow model that can be used to help manage the groundwater resources in the Lucerne Valley. The model developed for this study covers the period of 1942–2016 and can help evaluate various proposed water-management scenarios during different climatic and hydrologic conditions.

The aquifer system consists of a shallow aquifer, a confining unit, and middle and lower aquifers. These layered water-bearing units were identified based on geologic units of the mostly unconsolidated sediments and hydrologic properties. These alluvial deposits consist of clay, silt, sand, and gravel; some places also contain clay and silty clay lacustrine deposits. Several faults act, at least in part, as barriers to groundwater flow on the eastern, southern, and western edges of the basin. Present-day natural recharge is primarily from the infiltration of runoff from the San Bernardino Mountains to the south; however, stable and radioactive isotopes show that groundwater from the middle of the Lucerne Valley was older than about 10,000 years and probably was recharged as infiltration from streams draining the mountains in the Mojave Desert to the north, which probably does not occur under present-day climatic conditions. The annual average natural recharge for 1942–2016, estimated by a Basin Characterization Model, was about 635 acre-feet per year; the average amount of treated wastewater effluent transferred to the Lucerne Valley for artificial recharge annually ranged from about 1,500 to 4,000 acre-feet per year during 1980–2016. Pumpage estimates for 1942–2016 ranged from about 3,000 acre-feet in 1942 to about 18,300 acre-feet in 1984. The total cumulative amount of groundwater removed from the basin by pumping between 1942 and 2016 was estimated to be about 700,000 acre-feet, which was about 10 times greater than the cumulative amount of recharge to the entire Lucerne Valley groundwater basin. Before groundwater development, the direction of groundwater flow was from the southern part of the basin northward to discharge areas near Lucerne Lake, where it discharged through springs along the Helendale Fault and by evapotranspiration. Since the early 1900s, groundwater-level declines have mostly eliminated the areas where natural discharge occurred and exceeded 100 feet in the middle of the basin between the early 1950s and mid-1990s, and as much as 25 feet near the margins from about the mid-1950s to 2000s. A decrease in the rate of pumping after the mid-1990s lessened the hydraulic stress on the middle and lower aquifers and enabled hydraulic heads in the middle of the basin to recover slightly as groundwater near the margins of the basin moved toward the pumping depression. Although trends in groundwater levels in the center of the basin have reversed since the mid-1990s, levels at the basin margins continue to decline as the movement of groundwater from the margins fills the pumping depression and gradually flattens the groundwater table throughout the basin.

The long-term extraction of groundwater and associated dewatering of the fine-grained sediments present within the aquifer system has resulted in aquifer compaction and consequently land subsidence, primarily near Lucerne Lake. Analysis of interferometric synthetic aperture radar data shows that almost 11 inches of land subsidence has occurred south of Lucerne Lake between April 1992 and November 2009; less subsidence occurred elsewhere in the basin during this period. This differential land subsidence has caused fissures and cracks in the ground surface, which have buckled the pavement and undercut roads in several locations.

The Lucerne Valley Hydrologic Model was developed using the finite-difference groundwater modeling software One Water Hydrologic Model to represent the hydrologic conditions and stresses during 1942–2016. The model has a uniform grid of approximately 92 acres per cell (2,000 feet by 2,000 feet) and has four layers representing the water-bearing units. The results from the calibrated model simulations indicated that groundwater pumpage exceeded recharge, resulting in an estimated net cumulative depletion of groundwater storage (discharge minus recharge) of about 465,000 acre-feet from 1942 to 2016. The model simulated as much as 7.5 feet (90 inches; 2,286 millimeters) of aquifer compaction, which indicates the extensive fine-grained deposits and measured subsidence near Lucerne Lake.

Assessment of persistent chemicals of concern in white sturgeon (Acipenser transmontanus) in the Hanford Reach of the Columbia River, southeastern Washington, 2009

Released June 28, 2022 11:04 EST

2022, Scientific Investigations Report 2022-5020

Sean E. Payne, Daniel R. Wise, Jay W. Davis, Elena B. Nilsen

White sturgeon (Acipenser transmontanus) are long-lived, late-maturing, benthic-feeding fish that are ideal candidates for assessing the bioaccumulation of persistent chemicals. In this study, composite tissue samples of brain, liver, gonad, and fillet were collected from white sturgeon in 2009 from five sites in the Hanford Reach of the Columbia River near Hanford, Washington. The composite tissue samples at each site were analyzed for the concentrations of individual chemicals as well as the total concentrations of four chemical classes: (1) organochlorine (OC) pesticides, (2) industrial or personal care products, (3) polybrominated diphenyl ether (PBDE) congeners, and (4) polychlorinated biphenyl (PCB) congeners. The results showed that chemicals from all four classes were present in the fish, and that OC pesticides and degradation products (such as oxychlordane, fipronil sulfide, and dichlorodiphenyltrichloroethane (DDT) degradates, PBDE congeners, and PCB congeners) often were present in all tissues and at all sites. Gonad tissues generally had the highest total concentration of each chemical class, followed by brains, livers, and fillets. The concentrations of several chemicals or chemical classes exceeded many of the human health benchmarks for two different populations (general/recreational consumers and subsistence/Tribal consumers), and this was especially true for the total concentrations of DDT degradation products and PCB congeners. These results suggest that continued monitoring of resident fish in the Hanford Reach, as well as assessments of the health impacts on consumers of those fish, are warranted.

Potential effects of sea level rise on nearshore habitat availability for surf smelt (Hypomesus pretiosus) and eelgrass (Zostera marina), Puget Sound, Washington

Released June 28, 2022 09:59 EST

2022, Open-File Report 2022-1054

Collin D. Smith, Theresa L. Liedtke

In this study we examine the potential effects of three predicted sea level rise (SLR) scenarios on the nearshore eelgrass (Zostera marina L.) and surf smelt (Hypomesus pretiosus) spawning habitats along a beach on Bainbridge Island, Washington. Baseline bathymetric, geomorphological, and biological surveys were conducted to determine the existing conditions at the study site. The results of these surveys were coupled with a predictive model that estimates SLR-induced changes to coastal ecosystems based upon local topography and land-cover data. This model simulates the changes in nearshore habitat through time. The model inputs for SLR are probable values reported by the Intergovernmental Panel on Climate Change, and by user-defined values. The predicted effects of SLR are presented as (1) habitat type change and (2) the graphic response of developed dry land depicting the influence of shoreline armoring. This report describes the geophysical and biological characteristics at the Bainbridge Island study site, the modeling methods used to produce depictions of habitat changes, and a possible decrease in surf smelt spawning and an increase in eelgrass habitat availability in response to increases in sea level.

Biofilms in the Critical Zone: Distribution and mediation of processes

Released June 28, 2022 08:24 EST

2022, Book chapter, Biogeochemistry of the Critical Zone

Marjorie S. Schulz, Kristen L. Manies

Adam S. Wymore, Wendy H. Yang, Whendee L. Silver, William H. McDowell, Jon Chorover, editor(s)

Microbial biofilms occur in all levels of the Critical Zone (CZ); they are on and in the vegetation, throughout the soil-saprolite zone, and along fractures in deep subsurface. Here we discuss biofilms in each level of the CZ with a focus in the soil-saprolite continuum. We show how scanning electron microscope (SEM) images provide an appropriate scale to explore microbe mineral interactions in the CZ and can be used without extensive sample preparation. Through SEM imaging, we show that biofilms weather primary minerals, that macropores and fractures are hotspots of biofilm development, that biologic precipitation of short-range-order minerals (SROs) occurs in biofilms, and that biofilms are important in the process of organic matter stabilization.

Asking nicely: Best practices for requesting data

Released June 28, 2022 07:35 EST

2022, Ecological Indicators (70)

Steve R. Midway, Nicholas A. Sievert, Abigail Lynch, Joanna B. Whittier, Kevin L. Pope

Compiling disparate datasets into publicly available composite databases helps natural resource communities explore ecological trends and effectively manage across spatiotemporal scales. Though some studies have reported on the database construction phase, fewer have evaluated the data acquisition and distribution process. To facilitate future data sharing collaborations, Louisiana State University surveyed data providers and requestors to understand the characteristics of effective data requests and sharing. Data providers were largely U.S. natural resource agency personnel, and they reported that unclear data requests, privacy issues, and rigid timelines and formats were the greatest barriers toward providing data, but that they were motivated by improving science and collaboration. Data requestors identified challenges such as evolving needs, standardization issues, and insufficient resources (time and funding) as barriers to compiling data for these types of efforts. In a time of big data, open access, and collaboration, significant scientific advances can be made with effective requests and inclusion of data sets into larger and more powerful databases.

    The role of organic matter diversity on the Re-Os systematics of organic-rich sedimentary units: Insights into the controls of isochron age determinations from the lacustrine Green River Formation

    Released June 28, 2022 07:20 EST

    2022, Chemical Geology (604)

    Jeffrey T Pietras, Abby Dennett, David Selby, Justin E. Birdwell

    The range of 187Re/188Os values measured from samples of five organic-rich lacustrine mudstones units in the Eocene Green River Formation in the easternmost Uinta Basin covaries with organic matter diversity driven by changing water column conditions. A set of samples from the Douglas Creek Member has the highest pristane/phytane ratio and lowest β-carotane/n-C30 ratio compared to overlying units, indicating deposition in an oxic-anoxic environment with low salinity that would have allowed for the accumulation of a diverse assemblage of aquatic organisms. These samples define the broadest 187Re/188Os range of 1504. In contrast, samples from the R6 and Mahogany zones possess lower pristane/phytane ratios and higher β-carotane/n-C30 ratios indicating deposition in a more restricted lacustrine environment with elevated salinities and alkalinities that would have limited aquatic organic matter diversity. The R6 and Mahogany zones have the narrowest range of 187Re/188Os values measured in this study of 254.9 and 154.6, respectively. As noted by previous workers, these results suggest that organic matter diversity plays a primary role in determining the range of 187Re/188Os ratios in a sample set, and in turn the uncertainty of Re-Os age determinations from organic-rich sedimentary rocks.

    The Re-Os data from the R3 zone and R6 zone yield ages of 49.7 ± 3.4 Ma and 42.0 ± 18 Ma, respectively, which are statistically indistinguishable based on 2σ uncertainty from three previously reported Re-Os age determinations and those provided by 40Ar/39Ar geochronology of interbedded volcanic ash beds. Although the age uncertainty is high, these findings further highlight the importance of Re-Os geochronology in lacustrine basins, particularly those with thick mudstone successions that lack volcanic ash layers, reliable biostratigraphy, or magnetostratigraphic control. In these cases, even ages with large uncertainties can be useful to constrain burial history and thermal history models.

    Together, the initial 187Os/188Os ratios of five sets of samples analyzed from the Uinta Basin define the largest Os isotope stratigraphic record from any lacustrine basin compiled to date and record a shift from a value of 1.40 to 1.48 between the R3 and R4 zones in the lower part of the Parachute Creek Member. This small shift may signify a change in the chemical weathering products that entered the lake preserved 20 to 50 m above the contact between the Douglas Creek and the lower Parachute Creek members during a period when the basin transitioned from a shallow lake with mostly open hydrology to an alkaline lake with more frequent basin restrictions.

      Evaluating the efficacy of aerial infrared surveys to detect artificial polar bear dens

      Released June 28, 2022 07:19 EST

      2022, Wildlife Society Bulletin

      Susannah P Woodruff, Justin J Blank, Sheyna S Wisdom, Ryan H. Wilson, George M. Durner, Todd C. Atwood, Craig J Perham, Christina HM Pohl

      The need to balance economic development with impacts to Arctic wildlife has been a prominent subject since petroleum exploration began on the North Slope of Alaska, USA, in the late 1950s. The North Slope region includes polar bears (Ursus maritimus) of the southern Beaufort Sea subpopulation, which has experienced a long-term decline in abundance. Pregnant polar bears dig dens in snow drifts during winter and are vulnerable to disturbance, as den abandonment and mortality of neonates may result. Maternal denning coincides with the peak season of petroleum exploration and construction, raising concerns that human activities may disrupt denning. To minimize disturbance of denning polar bears, aerial infrared (AIR) surveys are routinely used to search for dens within planned industry activity areas and that information is used to implement mitigation. Aerial infrared surveys target the heat signature emanating from dens. Despite use by industry for >15 years, the efficacy of AIR and the factors that impact its ability to detect dens remains uncertain. Here, we evaluate AIR using artificial dens and observers naïve to locations to estimate detection probability and its relationship with covariates including weather variables, den characteristics, infrared sensor and altitude, and survey order to identify potential evidence of in-flight observer learning occurring between surveys. In December 2019 we constructed 14 dens (each with an artificial heat source), and 11 control sites (disturbed sites without dens). Between December 2019 and January 2020, 3 survey crews flew 6 independent AIR surveys within the vicinity of dens and control sites and video-recorded AIR imagery. Observers identified putative dens either in flight or during post-flight review of recordings. We assessed detection probability with a simple Bayesian model using 3 subsets of data: 1) all detection/non-detection data; 2) detection/non-detection data restricted to instances where sample sites were confirmed to have been properly scanned by AIR during post-study verification (i.e., when den locations were known); and 3) all dens visible on the recorded imagery during post-study verification, even if they were not seen during the survey or during post-flight review. Subsets 1 and 2 most closely resembled den surveys flown for oil and gas industry and had detection probabilities of 0.15 (95% CI = 0.08–0.23) and 0.24 (95% CI = 0.13–0.37), respectively. Detection probability was 0.41 (95% CI = 0.25–0.58) for subset 3. Higher wind speeds and larger den volume negatively influenced detection probability. Our low detection rate compared to previous studies could partially be the result of differences in study design, such as survey flight patterns. Our results suggest that AIR, as it is currently used, is unlikely to detect most polar bear dens in surveyed areas. Resource managers who use AIR should consider a suite of additional methods (e.g., habitat mapping, probabilistic den distribution, AIR methodology improvements) for minimizing impacts of industry on denning polar bears.

      Conservation action plan for diamond-backed terrapins in the Gulf of Mexico

      Released June 27, 2022 12:47 EST

      2022, Report

      Margaret Lamont, Daniel J. Catizone, Kristen Hart, editor(s)

      Diamondback terrapins are small estuarine turtles that are vital to the health of salt marsh and mangrove habitats. Their populations have declined for over a century due to many factors including coastal development, nest predation, pet trade and drowning in crab traps. Without action, terrapin populations will continue to decline. This document summarizes the Nature Conservancy's efforts in collaboration with the Diamondback Terrapin Working Group and the Gulf of Mexico Alliance to create a comprehensive regional plan to identify and advance terrapin-related research, management and conservation goals.

      Comparison of water year 2021 streamflow to historical data at selected sites in the Snake River Basin, Wyoming

      Released June 27, 2022 11:35 EST

      2022, Fact Sheet 2022-3043

      Ruth M. Law, James R. Campbell, Jerrod D. Wheeler, Cheryl A. Eddy-Miller

      The headwaters of the Snake River are in the mountains of northwestern Wyoming on lands primarily administered by the National Park Service and the Bridger-Teton National Forest. Streamflow from the Snake River Basin has been measured at some sites for more than 100 years. Water from this drainage basin is used for recreational, agricultural, and municipal uses and power generation. Because of the many uses of the water and the ongoing drought in the Western United States, there is interest in how streamflow in water year 2021 compared to the historical data. Historical streamflow data are defined as the operational period of the streamgage through water year 2020. A water year is named for the year in which it ends; therefore, water year 2021 is October 1, 2020, through September 30, 2021.

      Water quality monitoring: Exploring CMAP products

      Released June 27, 2022 11:34 EST

      2022, Report

      RESTORE Council Monitoring and Assessment Program

      The RESTORE Council Monitoring and Assessment Program (CMAP), administered by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), spatially and temporally inventoried programs in the Gulf of Mexico focused on water quality and habitat monitoring and mapping.

      Habitat monitoring: Exploring CMAP products

      Released June 27, 2022 11:22 EST

      2022, Report

      RESTORE Council Monitoring and Assessment Program

      The RESTORE Council Monitoring and Assessment Program (CMAP), administered by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), spatially and temporally inventoried programs in the Gulf of Mexico focused on water quality and habitat monitoring and mapping.

      RESTORE Council Monitoring and Assessment Program

      Released June 27, 2022 11:15 EST

      2022, Report

      RESTORE Council Monitoring and Assessment Program

      The RESTORE Council Monitoring and Assessment Program (CMAP), administered by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), spatially and temporally inventoried programs in the Gulf of Mexico focused on water quality and habitat monitoring and mapping.

      Exploring CMAP products: Mapping

      Released June 27, 2022 11:11 EST

      2022, Report

      RESTORE Council Monitoring and Assessment Program

      The RESTORE Council Monitoring and Assessment Program (CMAP), administered by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), spatially and temporally inventoried programs in the Gulf of Mexico focused on water quality and habitat monitoring and mapping.

      Statistical consideration of nonrandom treatment applications reveal region-wide benefits of widespread post-fire restoration action

      Released June 27, 2022 10:25 EST

      2022, Nature Communications (13)

      Allison B. Simler-Williamson, Matthew Germino

      Accurate predictions of ecological restoration outcomes are needed across the increasingly large landscapes requiring treatment following disturbances. However, observational studies often fail to account for nonrandom treatment application, which can result in invalid inference. Examining a spatiotemporally extensive management treatment-- post-fire seeding of declining sagebrush shrubs across the semiarid U.S. over two decades -- we quantify drivers and consequences of selection biases in restoration, using remotely sensed data. Treatments were disproportionately applied in more stressful, degraded ecological conditions. Failure to incorporate nonrandom treatment allocation led to the conclusion that costly, widespread seedings were unsuccessful; however, after considering biases, restoration positively affected sagebrush recovery. Treatment effect sizes varied with climate, indicating possible prioritization criteria for interventions. Our findings revise the perspective that widespread post-fire sagebrush seedings have been broadly “unsuccessful” and demonstrate how selection biases can pose substantive inferential hazards in observational studies of restoration efficacy and development of restoration theory.

      A numerical study of geomorphic and oceanographic controls on wave-driven runup on fringing reefs with shore-normal channels

      Released June 27, 2022 10:16 EST

      2022, Journal of Marine Science and Engineering (10)

      Curt D. Storlazzi, Annouk Rey, Ap van Dongeren

      Many populated, tropical coastlines fronted by fringing coral reefs are exposed to wave-driven marine flooding that is exacerbated by sea-level rise. Most fringing coral reef are not alongshore uniform, but bisected by shore-normal channels; however, little is known about the influence of such channels on alongshore variations on runup and flooding of the adjacent coastline. We con-ducted a parametric study using the numeric model XBeach that demonstrates that a shore-normal channel results in substantial alongshore variations in waves, wave-driven water levels, and the resulting runup. Depending on the geometry and forcing, runup is greater either on the coastline adjacent to the channel terminus or at locations near the alongshore extent of the channel. The impact of channels on runup increases for higher incident waves, lower incident wave steepness, wider channels, a narrower reef, and shorter channel spacing. Alongshore varia-tion of infragravity waves is predominantly responsible for large-scale variations in runup out-side the channel, whereas setup, sea-swell waves, and very-low frequency waves mainly increase runup inside the channel. These results provide insight into which coastal locations adjacent to shore-normal channels are most vulnerable to high runup events, using only widely available data such as reef geometry and offshore wave conditions.

      21st-century stagnation in unvegetated sand-sea activity

      Released June 27, 2022 07:02 EST

      2022, Nature Communications (13)

      Andrew Gunn, Amy E. East, Douglas J. Jerolmack

      Sand seas are vast expanses of Earth’s surface containing large areas of aeolian dunes—topographic patterns manifest from above-threshold winds and a supply of loose sand. Predictions of the role of future climate change for sand-sea activity are sparse and contradictory. Here we examine the impact of climate on all of Earth’s presently-unvegetated sand seas, using ensemble runs of an Earth System Model for historical and future Shared Socioeconomic Pathway (SSP) scenarios. We find that almost all of the sand seas decrease in activity relative to present-day and industrial-onset for all future SSP scenarios, largely due to more intermittent sand-transport events. An increase in event wait-times and decrease in sand transport is conducive to vegetation growth. We expect dune-forming winds will become more unimodal, and produce larger incipient wavelengths, due to weaker and more seasonal winds. Our results indicate that these qualitative changes in Earth’s deserts cannot be mitigated.

      Closing the gap on wicked urban stream restoration problems: A framework to integrate science and community values

      Released June 27, 2022 06:33 EST

      2022, Freshwater Science

      Brian M Murphy, Kathryn L Russell, Charles C. Stillwell, Robert J. Hawley, Mateo Scoggins, Kristina G. Hopkins, Matthew J. Burns, Kristine T Taniguchi-Quan, Kate H Macneale, Robert F. Smith

      Restoring the health of urban streams has many of the characteristics of a wicked problem. Addressing a wicked problem requires managers, academics, practitioners, and community members to make negotiated tradeoffs and compromises to satisfy the values and perspectives of diverse stakeholders involved in setting restoration project goals and objectives. We conducted a gap analysis on 11 urban stream restoration projects to identify disconnections, underperformance issues, and missing processes in the project structures used to develop restoration project goals and objectives. We examined the gap analysis results to investigate whether managers appropriately identified problem statements and met stated objectives. Projects that aimed to restore overall stream health commonly fell short for various reasons, including limited stakeholder and community input and buy-in, revealing potential limitations in the breadth of objectives, values, and stakeholder perspectives and knowledge types. Projects that emphasized integrating community values and diverse knowledge types tended to meet the expected outcomes of restoring stream processes through incremental solutions. Managers implementing more holistic solutions and values-driven approaches are more likely to consider diverse viewpoints from a variety of community local institutions. Based on these and other results, we propose a conceptual framework that integrates diverse perspectives and knowledge to enhance social and ecological outcomes of urban stream restoration. The framework also emphasizes the importance of setting objectives that support incremental solutions to foster more realistic expectations amongst stakeholders.

      Experimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream

      Released June 25, 2022 07:30 EST

      2022, PNAS Nexus

      Bridget Deemer, Charles Yackulic, Robert O Hall Jr., Michael Dodrill, Theodore Kennedy, Jeffrey Muehlbauer, David Topping, Nicholas Voichick, Mike Yard

      Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves sub-daily changes in water releases proportional to fluctuations in electrical power demand. This flow regime causes an artificial tide, wetting and drying channel margins and altering river depth and water clarity, all processes that are likely to affect primary production. In collaboration with dam operators, we designed an experimental flow regime whose goal was to mitigate negative effects of load following on ecosystem processes. The experimental flow contrasted steady-low flows on weekends with load following flows on weekdays. Here, we quantify the effect of this experimental flow on springtime gross primary production (GPP) 90-to-425 km downstream of Glen Canyon Dam on the Colorado River, AZ, USA. GPP during steady-low flows was 41% higher than during load following flows, mostly owing to non-linear reductions in sediment-driven turbidity. The experimental flow increased weekly GPP even after controlling for variation in weekly mean discharge, demonstrating a negative effect of load following on GPP. We estimate that this environmental flow increased springtime carbon fixation by 0.27 g C m–2 d–1, which is ecologically meaningful considering median C fixation in 356 U.S. rivers of 0.44 g C m–2 d–1 and the fact that native fish populations in this river are food-limited.

      Parks look for ways to alleviate Glen Canyon Dam’s dramatic downstream impacts

      Released June 24, 2022 13:10 EST

      2022, Park Science (36)

      Lonnie Pilkington, Joel B. Sankey, Dan Boughter, Taryn Preston, Cam C. Prophet

      Introduction Regardless of the location, time of day, or season, the grandeur of Grand Canyon National Park and Glen Canyon National Recreation Area inspires awe. Visitors can reflect on the sunlit colors of the towering canyon walls or witness the vibrant, golden display of Fremont cottonwood leaves each fall. For millions of years, the Colorado River has sculpted canyon country; for thousands of years, it has been a lifeline for humans, wildlife, and plants. But despite its wild appearance, the river does not flow freely; it is regulated by the upstream Glen Canyon Dam, which profoundly affects the surrounding natural environment and visitor experiences. The National Park Service and its partners in the Glen Canyon Dam Adaptive Management Program are working on a 20-year experimental project to restore some of the natural systems that were damaged or lost because of the dam. The program is administered by the Bureau of Reclamation. The project covers 296 miles of the Colorado River, from Glen Canyon Dam at Lake Powell Reservoir through the Grand Canyon to Pearce Ferry at Lake Mead Reservoir. Scientists from the U.S. Geological Survey lead the program’s experiments, some of which have already proved fruitful. A Changed Ecosystem Since its completion in 1963, the dam has changed downstream habitats along the river, adversely affecting some of them. Before the dam was built, sparsely vegetated sandbars along the Colorado River were more prevalent. River rafters and other backcountry adventurers valued these sandy beaches as campsites and break spots. Dam operations changed the river flow regime, decreasing the size and duration of large floods while also increasing the level of low flows. This caused native clonal plant species like arrowweed and non-native species such as tamarisk to encroach on sandbars, decreasing the size of campsite areas and degrading their condition. Previously commonplace, cottonwood and willow gallery forests that are ideal for bird habitat are now essentially nonexistent. This is because the regulated flows don’t allow for marsh back channels, which relied on periodic large floods. The dam has also affected archeological sites. Many of these sites are in pre-dam river sediment deposits, which provide a protective barrier against erosion. The dammed river now carries up to 95 percent less sediment, which means there is less sand available to cover the fragile sites. Sites are commonly in sand dunes along the river corridor, where wind re-supplies the dunes with sand blown from adjacent sandbars. Encroaching vegetation on the sandbars limits movement of what little sand is now available to cover and protect these sites. In 2018, the National Park Service, U.S. Geological Survey, and some of their partners began experimental vegetation treatments along the Colorado River below Glen Canyon Dam. This was in accordance with the 2016 Glen Canyon Dam Long-Term Experimental and Management Plan. Their purpose was to determine effective ways to mitigate the dam’s adverse impacts. The treatments have had some notable successes in improving the condition of campsites, archeological sites, and the riparian plant ecosystem.

      Na+/HCO3- cotransporter 1 (nbce1) isoform gene expression during smoltification and seawater acclimation of Atlantic salmon

      Released June 24, 2022 12:33 EST

      2022, Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology

      Jason P. Breves, Ian S. McKay, Victor Koltenyuk, Nastasia N. Nelson, Sean C. Lema, Stephen D. McCormick

      The life history of Atlantic salmon (Salmo salar) includes an initial freshwater phase (parr) that precedes a springtime migration to marine environments as smolts. The development of osmoregulatory systems that will ultimately support the survival of juveniles upon entry into marine habitats is a key aspect of smoltification. While the acquisition of seawater tolerance in all euryhaline species demands the concerted activity of specific ion pumps, transporters, and channels, the contributions of Na+/HCO3 cotransporter 1 (Nbce1) to salinity acclimation remain unresolved. Here, we investigated the branchial and intestinal expression of three Na+/HCO3 cotransporter 1 isoforms, denoted nbce1.1, -1.2a, and -1.2b. Given the proposed role of Nbce1 in supporting the absorption of environmental Na+ by ionocytes, we first hypothesized that expression of a branchial nbce1 transcript (nbce1.2a) would be attenuated in salmon undergoing smoltification and following seawater exposure. In two separate years, we observed spring increases in branchial Na+/K+-ATPase activity, Na+/K+/2Cl cotransporter 1, and cystic fibrosis transmembrane regulator 1 expression characteristic of smoltification, whereas there were no attendant changes in nbce1.2a expression. Nonetheless, branchial nbce1.2a levels were reduced in parr and smolts within 2 days of seawater exposure. In the intestine, gene transcript abundance for nbce1.1 increased from spring to summer in the anterior intestine, but not in the posterior intestine or pyloric caeca, and nbce1.1 and -1.2b expression in the intestine showed season-dependent transcriptional regulation by seawater exposure. Collectively, our data indicate that tissue-specific modulation of all three nbce1 isoforms underlies adaptive responses to seawater.

      Characteristics, relationships and precision of direct acoustic-to-seismic coupling measurements from local explosions

      Released June 24, 2022 12:28 EST

      2022, Geophysical Journal International (230) 2019-2035

      Robert E. Anthony, Josh Watzak, Adam T. Ringler, David C. Wilson

      Acoustic energy originating from explosions, sonic booms, bolides and thunderclaps have been recorded on seismometers since the 1950s. Direct pressure loading from the passing acoustic wave has been modelled and consistently observed to produce ground deformations of the near surface that have retrograde elliptical particle motions. In the past decade, increased deployments of colocated seismometers and infrasound sensors have driven efforts to use the transfer function between direct acoustic-to-seismic coupling to infer near-surface material properties including seismic velocity structure and elastic moduli. In this study, we use a small aperture (≈600 m) array of broadband seismometers installed in different manners and depths in both granite and sedimentary overburden to understand the fundamental nature and repeatability of seismic excitation from 1 to 15 Hz using horizontally propagating acoustic waves generated by 97 local (2–10 km) explosions. In agreement with modelling, we find that the ground motions induced by acoustic-to-seismic coupling attenuate rapidly with depth. We confirm the modelled relation between acoustic and ground motion amplitudes, but show that within one acoustic wavelength, the uncertainty in the transfer coefficient between seismic and acoustic energy at a given seismic station increases linearly with separation distance between the seismic and acoustic sensor. We attribute this observation to the rapid decorrelation of the infrasonic wavefield across small spatial scales and recommend colocating seismic and infrasound sensors for use in studies seeking to invert for near-surface material properties. Additionally, contrary to acoustic-to-seismic coupling theory and prior observations, we find that seismometers emplaced in granite do not record retrograde elliptical particle motions in response to direct pressure loading. We rule out seismometer tilt effects as a likely source of this observations and suggest that existing models of acoustic-to-seismic excitation may be too simplistic for seismometers placed in high rigidity materials.

      Overcoming “analysis paralysis” through better climate change scenario planning

      Released June 24, 2022 12:24 EST

      2022, Park Science (36)

      Gregor W. Schuurman, Brian W. Miller, Amy Symstad, Amber N. Runyon, Brecken C. Robb

      This "In Brief" article describes the use of scenario planning to facilitate climate change adaptation in the National Park Service. It summarizes best practices and innovations for using climate change scenario planning, with an emphasis on management outcomes and manager perspectives. The scenario planning approach and management outcomes highlighted in this article are the culmination of more than a decade of collaboration between the USGS and the National Park Service.

      Effects of flow regulation and drought on geomorphology and floodplain habitat along the Colorado River in Canyonlands National Park, Utah

      Released June 24, 2022 12:19 EST

      2022, River Research and Applications

      Paul Grams, Eric Head, Erich R. Mueller

      Streamflow regulation compounded by regional drought has resulted in up to 22% reduction in channel width, changes in channel planform, expansion of riparian vegetation, and alterations to floodplain habitat on the Colorado River in Meander Canyon, Utah. Although some changes in channel width occurred between the 1940s and 1980s, coinciding with major phases of upstream water development, larger decreases in channel width occurred between 1993 and 2006 during periods of exceptionally low annual floods. These findings illustrate that low runoff associated with regional drought and climate change may cause changes in river channel form that accelerate and compound the effects of upstream water development. Declining peak flows have also resulted in disconnection between the wetted channel and floodplains, where inundated back-levee depressions provide habitat used by two species of threatened and endangered native fish. Despite this disconnection, some back-levee depressions on the floodplain continue to be inundated by ~1.5-year recurrence floods via connections created by tributary mouths, floodplain outflow channels, and levee breaches excavated by resident beaver. These changes are shown by analysis of aerial images, high-resolution bathymetric and topographic measurements, and 2-dimensional streamflow modeling.

      Prairie grouse and wind energy: The state of the science and implications for risk assessment

      Released June 24, 2022 12:07 EST

      2022, Wildlife Society Bulletin

      John D. Lloyd, Cameron L. Aldridge, Taber D. Allison, Chad W. LeBeau, Lance B. McNew, Virginia L. Winder

      How to shape the anticipated build-out of industrial-scale renewable energy in a way that minimizes risk to wildlife remains contentious. This challenge is well-illustrated in the grasslands and shrub-steppe of North America. Here, several endemic species of grouse are the focus of intensive, long-term conservation action by a host of governmental and non-governmental entities, many of whom are now asking: will anticipated increases in the number of wind-energy facilities exacerbate declines or prevent recovery of these species? To help answer this question, we synthesized the potential consequences of wind-energy development on prairie grouse. Published literature on behavior or demography of prairie-grouse at wind-energy facilities is sparse, with studies having been conducted at only 5 different facilities in the United States. Only two of these studies met the standard for robust impact analysis by collecting pre-construction data and using control sites or gradient designs. Published results from only one of the species Greater Prairie-Chicken were available for >1 facility. Most studies also drew conclusions based on short (<4 years) periods of study, which is potentially problematic when studying these highly philopatric species. Given these caveats, we found that, in the short-term, adult survival and nest success appear largely unaffected in populations exposed to wind-energy facilities. However, changes in habitat use by female Greater Sage-Grouse and female Greater Prairie-Chicken during some seasons and reduced lek persistence among male Greater Prairie-Chickens near wind turbines suggest behavioral responses that may have demographic consequences. Prairie grouse can coexist with wind-energy facilities in some cases, at least in the short term, but important uncertainties remain, including the potential for long-term, cumulative effects of the extensive development expected as states attempt to meet goals for generating electricity from renewable sources.

      Late Paleoproterozoic to early Mesoproterozoic deposition of quartz arenites across southern Laurentia

      Released June 24, 2022 11:36 EST

      2022, Book chapter, Laurentia: Turning points in the evolution of a continent

      L. Gordon Medaris Jr., Christopher G. Daniel, Michael F. Doe, James V. Jones III, Joshua J. Schwartz

      Steven J. Whitmeyer, Michael L. Williams, Dawn A. Kellett, Basil Tikoff, editor(s)

      Supermature siliciclastic sequences were deposited between 1.64 Ga and 1.59 Ga over a broad swath of southern Laurentia in the Archean, Penokean, Yavapai, and Mazatzal Provinces. These siliciclastic sequences are notable for their extreme mineralogical and chemical maturity, being devoid of detrital feldspar and ferromagnesian minerals, containing the clay mineral kaolinite (or its metamorphic equivalent, pyrophyllite), and having a chemical index of alteration >95. Such maturity is the result of a perfect confluence of tectonic and climatic conditions, including a stable continental crust with low topographic relief (the Archean, Penokean, and Yavapai Provinces ca. 1.70 Ga), a warm humid climate, an elevated level of atmospheric CO2, and relatively acidic pore fluids in the critical zone. The weathered detritus was transported and deposited by southward-flowing streams across the Archean, Penokean, and Yavapai Provinces, ultimately to be deposited on 1.66 Ga volcanic and volcaniclastic rocks in the Mazatzal continental arc along the southern margin of Laurentia.

      Speciation with gene flow in a narrow endemic West Virginia cave salamander (Gyrinophilus subterraneus)

      Released June 24, 2022 10:54 EST

      2022, Conservation Genetics

      Evan H. Campbell Grant, Kevin P. Mulder, Adrianne B. Brand, Douglas B. Chambers, Addison H. Wynn, Grace Capshaw, Matthew L. Niemiller, John G. Phillips, Jeremy F. Jacobs, Shawn R. Kuchta, Rayna C. Bell

      Due to their limited geographic distributions and specialized ecologies, cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. We investigated the evolutionary history of the West Virginia Spring Salamander (Gyrinophilus subterraneus), estimated the population trend from historic and current survey data, and assessed the current potential for water quality threats to the cave habitat. Our genomic data (mtDNA sequence and ddRADseq-derived SNPs) reveal two, distinct evolutionary lineages within General Davis Cave corresponding to G. subterraneus and its widely distributed sister species, Gyrinophilus porphyriticus, that are also differentiable based on morphological traits. Genomic models of evolutionary history strongly support asymmetric and continuous gene flow between the two lineages, and hybrid classification analyses identify only parental and first generation cross (F1) progeny. Collectively, these results point to a rare case of sympatric speciation occurring within the cave, leading to strong support for continuing to recognize G. subterraneus as a distinct and unique species. Due to its specialized habitat requirements, the complete distribution of G. subterraneus is unresolved, but using survey data in its type locality (and currently the only known occupied site), we find that the population within General Davis Cave has possibly declined over the last 45 years. Finally, our measures of cave and surface stream water quality did not reveal evidence of water quality impairment and provide important baselines for future monitoring. In addition, our unexpected finding of a hybrid zone and partial reproductive isolation between G. subterraneus and G. porphyriticus warrants further attention to better understand the evolutionary and conservation implications of occasional hybridization between the species.

      Prioritizing habitats based on abundance and distribution of molting waterfowl in the Teshekpuk Lake Special Area of the National Petroleum Reserve, Alaska

      Released June 24, 2022 10:43 EST

      2022, Global Ecology and Conservation (38)

      Paul L. Flint, Vijay P. Patil, Bradley Shults, Sarah J. Thompson

      The National Petroleum Reserve in Alaska (NPR-A) encompasses more than 9.5 million hectares of federally managed land on the Arctic Coastal Plain of northern Alaska, where it supports a diversity of wildlife, including millions of migratory birds. Within the NPR-A, Teshekpuk Lake and the surrounding area provide important habitat for migratory birds and this area has been designated by the Bureau of Land Management as the Teshekpuk Lake Special Area (TLSA) because numerous waterfowl species use the area for breeding and molting. Our goal was to provide a mechanism for land managers to assess relative value of areas for molting waterfowl. This approach was based on the population densities of Pacific black brant (Branta bernicla nigricans) and cackling geese (Branta hutchinsii) and pre-defined thresholds for the minimum fraction of the population contained within selected areas. Prioritizations were based on long-term records of population density combined with global-positioning system data to reveal small-scale patterns of habitat use. The highest population density of the Pacific black brant was found along the Beaufort Sea coast on the eastern edge of the study area, whereas cackling geese were somewhat more widely distributed. Depending on the criteria used for prioritization and width of protective buffers placed around selected units, 52–85% of the Goose Molting Area was identified as high-priority area. The effectiveness of this approach to protection of molting birds assumes that buffers around high value units are wide enough to provide adequate protection from disturbance related to oil and gas development.

      Provenance of Devonian-Carboniferous strata of Colorado: The influence of the Cambrian and the Proterozoic

      Released June 24, 2022 10:24 EST

      2022, Rocky Mountain Geology (57) 1-21

      Christopher S. Holm-Denoma, William A. Matthews, Linda Soar, Mark W. Longman, James W. Hagadorn

      We report new LA-ICPMS U-Pb detrital zircon ages and sedimentary petrology of silty to sandy limestones and dolostones, as well as calcareous to dolomitic sandstones of the Devonian-Carboniferous (Mississippian) Chaffee Group, as well as detrital zircon ages from the Late Cambrian Sawatch Quartzite and a U-Pb zircon crystallization age on a late Mesoproterozoic (1087.9 13.5 Ma) granitoid of underlying basement from the Eagle basin of Colorado. Grain populations in the Chaffee Group are mostly bimodal, with over 84% of zircons centered around a Paleoproterozoic (ca. 1.78 Ga) mode typical of the Yavapai Province that forms much of the basement of Colorado and an early Mesoproterozoic (ca. 1.42 Ga) mode typical of A-type granites that intrude this region. A notable late Mesoproterozoic (ca. 1.08 Ga) mode exists in some Chaffee samples, giving those samples a trimodal detrital zircon age distribution. These bipartite or tripartite detrital zircon age modes exist in Cambrian, Devonian and Carboniferous strata from paleogeographically adjacent successions, but the correlation between the Chaffee zircons is highest with the regions basal Cambrian sandstones (Sawatch, Flathead, Ignacio formations) which have similar (1.08 Ga, 1.43 Ga, 1.71 Ga) zircon populations and a paucity of >1.8 Ga grains. This similarity suggests that the majority of grains in the Chaffee Group derive from recycling of these basal sandstones, and that little sediment was derived directly from then-exposed Precambrian basement highs, from the Wyoming Craton to the north, or from Paleoproterozoic arcs and orogens to the west and northeast. Minor Mesoarchean to early Paleoproterozoic (ca. 3.00 to 2.40 Ga) grains exist in the Chaffee Group, an attribute shared by the Late Ordovician Harding Sandstone of Colorados Front Range, but that is absent from the regions underlying Cambrian sandstonessuggesting some recycled mixture of Cambrian and Ordovician sedimentary rocks. No near-depositional age grains are present in the Chaffee Group; the youngest grain is Early Devonian (~417 Ma), >45 m.y. older than these strata, and Paleozoic grains are extremely uncommon (<0.1%; n=2927 grains).

      Wading bird foraging on a wetland landscape: A comparison of two strategies

      Released June 24, 2022 08:28 EST

      2022, Mathematical Biosciences and Engineering (19) 7687-7718

      Hyo Won Lee, Donald L. DeAngelis, Simeon Yurek, Stephen Tennenbaum

      Tactile-feeding wading birds, such as wood storks and white ibises, require high densities of prey such as small fishes and crayfish to support themselves and their offspring during the breeding season. Prey availability in wetlands is often determined by seasonal hydrologic pulsing, such as in the subtropical Everglades, where spatial distributions of prey can vary through time, becoming heterogeneously clumped in patches, such as ponds or sloughs, as the wetland dries out. In this mathematical modeling study, we selected two possible foraging strategies to examine how they impact total energetic intake over a time scale of one day. In the first, wading birds sample prey patches without a priori knowledge of the patches' prey densities, moving from patch to patch, staying long enough to estimate the prey density, until they find one that meets a predetermined satisfactory threshold, and then staying there for a longer period. For this case, we solve for a wading bird's expected prey intake over the course of a day, given varying theoretical probability distributions of patch prey densities across the landscape. In the second strategy considered, it is assumed that the wading bird samples a given number of patches, and then uses memory to return to the highest quality patch. Our results show how total intake over a day is impacted by assumptions of the parameters governing the spatial distribution of prey among patches, which is a key source of parameter uncertainty in both natural and managed ecosystems. Perhaps surprisingly, the foraging strategy that uses a prey density threshold generally led to higher maximum potential prey intake than the strategy for using memory to return to the best patch sampled. These results will contribute to understanding the foraging of wading birds and to the management of wetlands.

      2021 assessment of the Joint Fire Science Program’s Fire Science Exchange Network

      Released June 23, 2022 18:40 EST

      2022, Scientific Investigations Report 2022-5052

      Natasha Collins, James Meldrum, Rudy Schuster, Nina Burkardt

      The U.S. Geological Survey (USGS), on behalf of the Joint Fire Science Program (JFSP), conducted an evaluation of the Fire Science Exchange Network (FSEN), which connects wildland fire scientists and practitioners through 15 individual exchanges across the United States to help address complex wildfire needs and challenges. The study was divided into two phases: The first phase was a literature review and synthesis from materials provided by the JFSP Board. Phase two, informed by the JFSP review, was an online survey sent to more than 16,000 exchange network users compiled from the electronic mailing lists for each exchange. Respondents were asked their opinions on the importance, quality, and delivery of information for 16 key fire science topics, the prioritization of FSEN objectives, and from where and to what extent respondents are gathering information on key topics. Overall, respondents believed that sharing information and building relationships are the most important objectives of the FSEN. Respondents believed the exchange network is successful in delivering information for many of the key science topics (for example, fire behavior, prescribed fire, firefighter safety, and incident management); gaps were identified in scientific resources available for some topics (for example, economic impacts, social science and human dimensions, Indigenous knowledge). Most respondents participated in one to two exchanges and relied heavily on their respondent location (the exchange in which they primarily live and [or] work) for information. Respondents also often relied on external sources outside of the exchange network. Regional patterns emerged in information gathering whereby respondents from exchanges in the western United States (for example, Northern Rockies, Southern Rockies, and Northwest) and respondents from exchanges in the eastern United States (for example, Southern, Oak Woodlands, and Tallgrass) frequently gathered information from each other.

      Characterization of the partial oxidation products of crude oil contaminating groundwater at the U.S. Geological Survey Bemidji research site in Minnesota by elemental analysis, radiocarbon dating, nuclear magnetic resonance spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry

      Released June 23, 2022 17:40 EST

      2022, Open-File Report 2022-1042

      Kevin A. Thorn, Ananna Islam, Sunghwan Kim

      In oil spill research, a topic of increasing attention during the last decade has been the environmental impact of the partial oxidation products that result from transformation of the petroleum in freshwater, marine, and terrestrial ecosystems. This report describes the isolation and characterization of the partial oxidation products from crude oil contaminating groundwater at the long-term U.S. Geological Survey Bemidji research site in Minnesota. As the result of a pipeline burst in August 1979, a body of light aliphatic crude oil is present from the land surface to 2 meters below the water table in a shallow sand and gravel aquifer in a remote area outside Bemidji, Minnesota, United States. Biodegradation has resulted in the formation of a plume of dissolved organic carbon (DOC) downgradient from the oil body. Groundwater has also been contaminated in an area known as the spray zone, from vertical infiltration of DOC resulting from biodegradation of oil in the soil column, and possibly from photooxidation of oil at the soil surface. The majority of DOC in the contaminated groundwater is in the form of nonvolatile organic acids (NVOAs) which represent the partial oxidation products of the crude oil constituents. The NVOAs have been classified into three fractions according to their isolation on XAD resins: hydrophobic neutrals (HPON), hydrophobic acids (HPOA), and hydrophilic acids (HPIA). These fractions of NVOAs were isolated from wells downgradient from the oil body (sampling well numbers 533, 532, 530, 515), in the spray zone (603), and from an uncontaminated well upgradient of the oil body (310) between the years 1986 and 1989, and again from wells 530 and 603 in 1998. The samples have been characterized by elemental analysis, radiocarbon dating, carbon-13 nuclear magnetic resonance spectroscopy (13C NMR), and negative-mode (-) electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR-MS), with a particular focus on fractions from wells 310, 530, and 603.

      All the characterization data indicate that the NVOAs from contaminated wells are distinguishable from the background DOC. Carbon-14 (14C) ages of NVOAs from contaminated wells ranged from 3,615 to 18,985 years before the present, whereas the background DOC from the aquifer was post-bomb (post 1950). By elemental analysis, NVOAs from contaminated wells had higher sulfur but lower nitrogen contents than the background. By electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, number average molecular weights determined from assigned molecular formulas ranged from 416 to 486 daltons for the HPOA and HPIA fractions from both background and contaminant wells. NVOAs from contaminated wells had significantly greater numbers of assigned molecular formulas containing sulfur, with elevated concentrations of the S1O4-10 species in particular. Compared to the background, HPOA and HPIA fractions from contaminant wells had a broader range of double bond equivalents (DBEs) within On compound classes (n is number of atoms). Additionally, within On compound classes, contaminant well HPOA fractions had a greater abundance of lower n (less than eight) than the background. Contaminant well double bond equivalents versus carbon number (C#) plots of oxygen compound classes suggest oil-derived aliphatic compounds in the range from C12 to C22 in HPOA and HPIA fractions and oil-derived compounds containing aromatic or saturated rings in the approximate range from C20 to C30 are present in HPOA fractions.

      The data suggest the NVOAs originate from biodegradation of several classes of C12 and greater crude oil constituents: sulfur-containing constituents, including possibly the resins and asphaltenes; constituents containing aromatic rings substituted with methyl groups, including alkylaromatic and naph-
      thenoaromatic compounds, and C12 to C22 alkyl constituents. The overall similarities of the carbon-13 nuclear magnetic resonance spectra for the well 603 and 530 samples from the two sampling dates suggest that a steady state in the composition of the partial oxidation products in each of the two wells had been reached between 1986–1989 and 1998.

      Using microbial source tracking to identify fecal contamination sources in Great South Bay on Long Island, New York

      Released June 23, 2022 12:15 EST

      2022, Scientific Investigations Report 2022-5057

      Tristen N. Tagliaferri, Shawn C. Fisher, Christopher M. Kephart, Natalie Cheung, Ariel P. Reed, Robert J. Welk

      The U.S. Geological Survey worked in cooperation with the New York State Department of Environmental Conservation to assess the potential sources of fecal contamination entering a part of Great South Bay (referred to as Great South Bay for the purposes of this report) near the hamlets of West Sayville, Sayville, and Bayport on the southern shore of Suffolk County on Long Island, New York. Water samples are routinely collected by the New York State Department of Environmental Conservation in the bay and analyzed for fecal coliform bacteria, an indicator of fecal contamination, to determine the need for closure of shellfish beds for harvest and consumption. Fecal coliform and other bacteria are an indicator of the potential presence of pathogenic (disease-causing) bacteria. However, indicator bacteria alone cannot determine the biological or geographical sources of contamination; therefore, microbial source tracking was implemented to determine various biological sources of contamination. In addition, information such as the location, weather and season, and surrounding land use where a sample was collected help determine the geographical source and conveyance of land-based water to the embayment. Analysis revealed that the most substantial source of fecal contamination to Great South Bay was discharge from sites draining ponds and wetlands into the tributaries sampled, Brown and Green Creeks, particularly during the summer months. Fecal coliform bacteria at sites where ponds and wetlands drain are increased by stormwater runoff, which is another substantial source of fecal contamination. Sites with high concentrations of fecal coliform bacteria in the summer exacerbated by stormwater include the Brown Creek Culvert at Middle Road, Mill Pond Culvert near South Street, and Green Creek Culvert near Montauk Highway sites. The canine Bacteroides (BacCan) marker was the most frequently detected microbial source tracking marker with 15 positive detections in surface water across the landscape, followed by the waterfowl Helicobacter (GFD) marker with 9 detections and the human Bacteroides (HF183) marker with 4 detections in surface water (excluding 2 detections in sediment). The ruminant Bacteroides (Rum2Bac) marker was not detected in any samples collected during this study. The detection frequency of BacCan was similar for all sampling conditions and seasons, suggesting canine influence is unrelated to weather events and is a year-round occurrence. BacCan was detected in 14 of 16 source samples and only 1 of 16 receptor samples, which suggests that canine fecal contamination is likely diluted in the bay. There was a similar amount of marker detections when comparing weather condition (wet or dry) and season (winter or summer), suggesting that fecal contamination was unrelated to weather events or time of year. Eight waterfowl marker detections were in samples collected during the winter, and only one during the summer, implicating seasonal avian fecal contamination throughout the embayment. The human marker was detected in only one surface-water receptor sample, during the wet winter sampling event at the Green Creek Mid-Bay site. Three of four human marker detections were in the samples collected during the wet winter sampling event, indicating that weather and season may influence the presence of human markers in Great South Bay, but human markers are not overly prevalent.

      Characterizing storm-induced coastal change hazards along the United States West Coast

      Released June 23, 2022 11:17 EST

      2022, Nature--Scientific Data (9)

      James B. Shope, Li H. Erikson, Patrick L. Barnard, Curt Storlazzi, Katherine A. Serafin, Kara S. Doran, Hilary F. Stockdon, Borja G. Reguero, Fernando J. Mendez, Sonia Castanedo, Alba Cid, Laura Cagigal, Peter Ruggiero

      Traditional methods to assess the probability of storm-induced erosion and flooding from extreme water levels have limited use along the U.S. West Coast where swell dominates erosion and storm surge is limited. This effort presents methodology to assess the probability of erosion and flooding for the U.S. West Coast from extreme total water levels (TWLs), but the approach is applicable to coastal settings worldwide. TWLs were derived from 61 years of wave and water level data at shore-perpendicular transects every 100-m along open coast shorelines. At each location, wave data from the Global Ocean Waves model were downscaled to the nearshore and used to empirically calculate wave run-up. Tides were simulated using the Oregon State University’s tidal data inversion model and non-tidal residuals were calculated from sea-surface temperature and pressure anomalies. Wave run-up was combined with still water levels to generate hourly TWL estimates and extreme TWLs for multiple return periods. Extremes were compared to onshore morphology to determine erosion hazards and define the probability of collision, overwash, and inundation.

      Revisions to the Virginia Coastal Plain hydrogeologic framework southwest of the James River

      Released June 23, 2022 08:00 EST

      2022, Scientific Investigations Report 2022-5049

      Samuel H. Caldwell, E. Randolph McFarland

      New drilling information reveals that altitudes of some hydrogeologic units of the Virginia Coastal Plain aquifer system differ by as much as 50 feet (ft) from those previously known, namely the Aquia and Potomac aquifers, the Potomac confining zone, and the Nanjemoy-Marlboro and Saint Marys confining units. In addition, the lateral margins of some hydrogeologic units are located as much as several miles from previously estimated locations. The largest revisions to unit margins were for the Aquia aquifer and the Nanjemoy-Marlboro and Saint Marys confining units. Interpretation of new geophysical logs, sediment core, and cuttings as well as revised interpretations to existing data indicate channels and embayments are also preserved on eroded top surfaces of the shallowest hydrogeologic units including the Yorktown confining zone, Yorktown-Eastover aquifer, Saint Marys confining unit, Potomac confining zone, and Potomac aquifer.

      Enhanced details on the configuration of part of the aquifer system southwest of the James River are provided by sediment cores and cuttings as well as geophysical logs from 36 recently drilled boreholes. These, along with reinterpretation of data from 93 preexisting boreholes, form the basis for revised top-surface altitudes and margins of hydrogeologic units beneath parts of Prince George, Surry, Sussex, Isle of Wight, and Southampton Counties and the cities of Franklin and Suffolk.

      Groundwater withdrawals in the Virginia Coastal Plain cause widespread water-level declines, create the potential for saltwater intrusion, and contribute to regionwide land subsidence. A description of the aquifer system, termed a hydrogeologic framework, was developed by the U.S. Geological Survey in 2006 and provides information needed to base withdrawal-permitting decisions by the Virginia Department of Environmental Quality. This revision of part of the hydrogeologic framework southwest of the James River is based on interpretations of both new and previously analyzed borehole data. The revision is strictly confined to the study area extent and hydrogeologic units not found within the study area were not revised and are not discussed in this report. The newly determined hydrogeologic-unit altitudes and margins have implications for groundwater-withdrawal permitting. New interpretations have found that the Yorktown Eastover aquifer is absent in the southwestern part of the City of Suffolk, owing to what is most likely an isolated area of sediment-texture facies change. Most notably, the top-surface altitudes of the Aquia and Potomac aquifers have been lowered by as much as 50 ft from previous interpretations. This means that wells previously believed to be screened in the top of the Potomac aquifer could, based on these new interpretations, be screened in the bottom of the Aquia aquifer. These changes to aquifers in which wells are screened means that there is potentially more room in the groundwater withdrawal permitting for the Potomac aquifer, the largest and most productive aquifer in Virginia, and overpumping occurring in the Aquia aquifer.

      Mapping the altitude of the top of the Dockum Group and paleochannel analysis using surface geophysical methods on and near Cannon Air Force Base in Curry County, New Mexico, 2020

      Released June 22, 2022 14:13 EST

      2022, Scientific Investigations Report 2022-5050

      Jason D. Payne, Andrew P. Teeple, Jeremy McDowell, David Wallace, Walker A. Hancock

      The hydrogeology on and near Cannon Air Force Base (AFB) in eastern New Mexico was assessed to gain a better understanding of preferential groundwater flow paths through paleochannels. In and near the study area, paleochannels incised the top surface of the Dockum Group (Chinle Formation) and were subsequently filled in with electrically resistive coarse-grained sediments of the overlying Ogallala Formation, resulting in a preferential groundwater flow path in the form of a paleochannel network. A better understanding of the spatial characteristics of this preferential groundwater flow path is needed to support ongoing efforts to remediate groundwater contamination at Cannon AFB. Therefore, the U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, used surface geophysical resistivity methods and data compiled from previous studies to better understand the spatial distribution and characteristics of the paleochannel network incised into the top of the Dockum Group.

      Previous studies have shown these paleochannels incised into the top of the Dockum Group with increasing resolution, but limited borehole data on and near Cannon AFB continued to make accurately mapping the top of Dockum Group challenging. For this study, surface geophysical resistivity measurements in the form of time-domain electromagnetic soundings made by the U.S. Geological Survey were used in conjunction with data previously published by Architecture, Engineering, Construction, Operations, and Management and borehole data compiled from the New Mexico Water Rights Reporting System database to prepare an updated map of the top of the Dockum Group that includes the location and characteristics of paleochannels incised into the top of the Dockum Group (Chinle Formation). A total of 149 borehole picks (determinations of the tops and bases of geologic units and their hydrogeologic-unit equivalents) were obtained from previous studies, along with 72 additional borehole picks from the New Mexico Water Rights Reporting System database and 43 picks from newly collected time-domain electromagnetic soundings. The data were gridded and contoured using Oasis Montaj v. 9.8.1.

      The updated map of the top of Dockum Group has many areas of uncertainty greater than 20 feet, because there are not enough data for the gridding process to reliably determine a value. However, this interpretation of the altitude of the top of the Dockum Group represents a substantial improvement in data resolution compared to previous studies.

      Two methodologies were used to evaluate paleochannels incised in the top of the Dockum Group across the study area: (1) trend-removal grid analysis and (2) analysis with Esri’s ArcMap Hydrology toolset. These two paleochannel analysis techniques show groundwater flow direction as well as areas having the deepest saturated thickness. Hydrologically, these techniques show where aquifer storage is highest (in the deepest parts of the paleochannel network), as well as the spatial distribution of preferential groundwater flow paths (the paleochannels). The analyses indicate a large paleochannel trending to the southeast, with smaller channels feeding in from the west. Areas where groundwater management could be more beneficial are indicated by locations where these flow lines intersect the deeper parts of the paleochannel.

      Community for data integration 2020 annual report

      Released June 22, 2022 13:00 EST

      2022, Open-File Report 2022-1034

      Leslie Hsu, Amanda N. Liford, Grace C. Donovan

      The Community for Data Integration is a community of practice whose purpose is to advance the data integration capabilities of the U.S. Geological Survey. In fiscal year 2020, the Community for Data Integration held 11 monthly forums, facilitated 13 collaboration areas, and supported 13 projects. The activities supported the broad U.S. Geological Survey priority of producing building blocks for doing integrated predictive science. Specifically, the activities supported tools and methods for findable, accessible, interoperable, and reusable (FAIR) data and wildland fire and water prediction. Through these efforts, community members were informed of new and emerging technologies and data topics that helped them accomplish their professional responsibilities.

      By land, air, and water — U.S. Geological Survey science supporting fish and wildlife migrations throughout North America

      Released June 22, 2022 11:00 EST

      2022, Fact Sheet 2022-3030

      Mona Khalil, Mark Wimer, David Hu, Michael Adams, Melanie Steinkamp, Suzanna C. Soileau

      Countless species of animals—big game, birds, bats, insects, amphibians, reptiles, and fish—migrate to reach suitable habitats to feed, reproduce, and raise their young. Animal migrations developed over millennia commonly follow migration corridors—unique routes for each species—to move among seasonal habitats. Changes along those corridors, whether from human development (buildings, roads, dams) or from natural disturbances (for example, climate change, drought, fire, flooding, or invasive species), can make them harder to navigate. The U.S. Geological Survey’s Ecosystems Mission Area provides science that assists land managers in mapping, enhancing, protecting, and reconnecting migration corridors critical for diverse fish and wildlife populations that migrate, such as Odocoileus hemionus (mule deer) and Antilocapra americana (pronghorn), trout and salmon, salamanders, tortoises, bats, and Danaus plexippus (monarch butterflies).

      Evaluating the use of video cameras to estimate bridge scour potential at four bridges in southwestern Montana

      Released June 22, 2022 08:03 EST

      2022, Fact Sheet 2022-3040

      Daniel W. Armstrong, Stephen R. Holnbeck, Katherine J. Chase

      The U.S. Geological Survey, in cooperation with the Montana Department of Transportation, installed cameras and large-scale particle image velocimetry (LSPIV) recording equipment at four sites where the U.S. Geological Survey and Montana Department of Transportation are monitoring bridge scour using other methods. Determination of stream velocities is an important component of hydraulic engineering, river ecology, and fluvial geomorphology. LSPIV is an emerging technique that can be used to estimate stream surface velocities and streamflow using video cameras. Video from the camera is referenced to known locations on streambanks, and postprocessed using computer software that calculates water surface velocity and flow direction between video frames.

      The goal of the study was to determine if LSPIV can increase the accuracy of current bridge scour prediction methods using video recordings from 2019 to 2021. Scour around piers is one of the primary failure mechanisms for bridges and poses threats to public safety and interstate commerce. LSPIV installations can capture the flow velocities and directions near bridge piers where other measurement methods might fail or be too dangerous. Additional benefits to the LSPIV technique were continuous data collection throughout the hydrologic cycle and enhanced safety of the methods for estimating velocity magnitude and direction during flood events. Limitations of the LSPIV technique included the angle of the camera to incoming flow; video recordings that were not usable because of ice cover, night, or high winds; and vegetation along the streambank that interfered with water flow analysis. Future applications of the LSPIV technique may continue to improve the processing of the video and reduce limitations for this process.

      Characterizing mauka-to-makai connections for aquatic ecosystem conservation on Maui, Hawaiʻi

      Released June 22, 2022 07:26 EST

      2022, Ecological Informatics (70)

      Ella Wilmot, Jesse P. Wong, Yinphan Tsang, Abigail Lynch, Dana M. Infante, Kirsten L. L. Oleson, Ayron Strauch, Hannah Clilverd

      Mauka-to-makai (mountain to sea in the Hawaiian language) hydrologic connectivity – commonly referred to as ridge-to-reef – directly affects biogeochemical processes and socioecological functions across terrestrial, freshwater, and marine systems. The supply of freshwater to estuarine and nearshore environments in a ridge-to-reef system supports the food, water, and habitats utilized by marine fauna. In addition, the ecosystem services derived from this land-to-sea connectivity support social and cultural practices (hereafter referred to as socio-cultural) including fishing, aquaculture, wetland agriculture, religious ceremonies, and recreational activities. To effectively guide island resource management, a better understanding of the linkages from ridge-to-reef across natural and social usages is critical, particularly in the context of climate change, with anticipated increasing temperature and shifting precipitation patterns. The objective of this study was to identify spatial linkages that promote multiple and diverse uses, following the ridge-to-reef concept, at an island-wide scale to identify regions of high conservation importance for aquatic resources. We selected the Island of Maui as a study representative of many Pacific islands. Diverse datasets, including agricultural lands within watersheds, wetland locations, presence of stream species, indicators of freshwater input from streams, coral cover, nearshore fish biomass, socio-cultural data such as fishpond locations, wetland taro cultivation, beach recreation use, and lastly the dynamically downscaled Coupled Model Intercomparison Project Phase (CMIP5) future climate projections scenarios (Representative Concentration Pathway (RCP) 4.5 & 8.5) were used to examine the spatial linkages through hydrological connectivity from land to the sea. Zonation spatial planning software was used to prioritize areas of high management and conservation value and to help inform aquatic resources management. The resulting prioritized areas included many minimally disturbed watersheds in east Maui and western nearshore and coastal zones that are adjacent to diverse coral reefs. These results are driven by the importance of fish biomass and coral reef distribution as well as traditional wetland taro cultivation and coastal access points for recreation. These results underline the importance of examining ridge-to-reef systems for aquatic resource management and including important social and cultural values in resource management upon planning adaptation strategies for climate change. Improving our understanding of diverse natural and socio-cultural influences on habitat conditions and their values in these areas provides an opportunity to strategically plan future management and conservation actions.


      Ecological status and trends of the Upper Mississippi and Illinois Rivers

      Released June 22, 2022 07:15 EST

      2022, Open-File Report 2022-1039

      Jeffrey N. Houser, editor(s)

      Executive Summary

      This report assesses the status and trends of selected ecological health indicators of the Upper Mississippi River System (UMRS) based on the data collected and analyzed by the Long Term Resource Monitoring element of the Upper Mississippi River Restoration program, supplemented with data from other sources. This report has four objectives: providing a brief introduction of the UMRS, including its significance, history, modern-day stressors, and recent research; using ecological indicators to describe the status of the river system and where and how it has changed from circa 1993 to 2019; discussing management and restoration implications of these changes; and highlighting the fundamental role of long-term monitoring in the understanding, management, and restoration of large-floodplain rivers.

      The data were collected in the six Long Term Resource Monitoring element study reaches that spanned much of the UMRS and the various gradients contained therein. These study reaches included Navigation Pools 4, 8, 13, and 26; the part of the Unimpounded Reach of the Upper Mississippi River between Grand Tower and Cairo, Illinois; and the La Grange Pool on the Illinois River. The indicators included in this report describe the status and trends for the hydrology, geomorphology, floodplain vegetation, water quality, vegetation, and fishes of the UMRS. Many of the indicators of river ecosystem health changed significantly over the nearly 30 years of our evaluation. However, there was substantial spatial variability in the magnitude and timing of those changes among study reaches. Few indicators changed everywhere or nowhere; most indicators changed in some reaches but not others. The quantitative assessments of these indicators describe how the conditions of the river differ across hydrogeomorphic and climate gradients and through time and are intended to support the restoration and management of the UMRS.

      Woods Hole Coastal and Marine Science Center — 2021 Annual Report

      Released June 21, 2022 13:00 EST

      2022, Circular 1495

      Sara Ernst

      The 2021 annual report of the U.S. Geological Survey Woods Hole Coastal and Marine Science Center highlights accomplishments of 2021, includes a list of 2021 publications, and summarizes the work of the center, as well as the work of each of its science groups. This product allows readers to gain a general understanding of the focus areas of the center’s scientific research and learn more about specific projects and progress made throughout 2021, all while enjoying photographs taken in various environments and laboratories, and applicable maps and figures.

      Planetary geologic mapping protocol—2022

      Released June 21, 2022 09:19 EST

      2022, Techniques and Methods 11-B13

      James A. Skinner Jr., Alexandra E. Huff, Sarah R. Black, Holly C. Buban, Corey M. Fortezzo, Tenielle A. Gaither, Trent M. Hare, Marc A. Hunter

      The Planetary Geologic Mapping Protocol covers the idealized process of compiling a NASA-funded map product of a non-terrestrial solid surface planetary body for U.S. Geological Survey (USGS) publication and summarizes technical specifications of the Mapping Process for authors and reviewers. Directed by community and programmatic recommendations, the USGS Planetary Geologic Map Coordination Group assembled the content herein to aid the timely production of USGS map products. This document can be also used as a reference document by those researchers who are completing geologic maps that will be published outside the USGS.

      Volcano and earthquake monitoring plan for the Yellowstone Caldera system, 2022–2032

      Released June 21, 2022 08:56 EST

      2022, Scientific Investigations Report 2022-5032

      Yellowstone Volcano Observatory

      Executive Summary

      The Yellowstone Volcano Observatory (YVO) is a consortium of nine Federal, State, and academic agencies that: (1) provides timely monitoring and hazards assessment of volcanic, hydrothermal, and earthquake activity in and around Yellowstone National Park, and (2) conducts research to develop new approaches to volcano monitoring and better understand volcanic activity in the Yellowstone region and elsewhere. The U.S. Geological Survey (USGS) arm of YVO is also responsible for monitoring and reporting on volcanic activity in the Intermountain West of the United States.

      The previous YVO monitoring plan for the Yellowstone region spanned 2006–2015 and focused on strengthening the region-wide coverage, or backbone, of monitoring systems (Yellowstone Volcano Observatory, 2006). The goals of that plan have largely been achieved thanks to significant investments in instrumentation and infrastructure, especially by the National Science Foundation EarthScope Plate Boundary Observatory (now known as the Network Of The Americas, or NOTA) and the American Reinvestment and Recovery Act. This revision of the monitoring plan, covering 2022–2032, builds upon these improvements to monitoring systems in the Yellowstone region while also accounting for new insights into the dynamics of the area’s seismic, volcanic, and hydrothermal activity. These additional improvements are designed to fill gaps in the monitoring network and to better understand and track hazards associated with hydrothermal processes. These improvements include:

      • Conversion of remaining analog seismic stations to digital,
      • Addition of Global Positioning System (GPS) stations in the vicinity of Norris Geyser Basin and other areas where changes in deformation rate and style have been observed,
      • Implementation of continuous gas monitoring in several areas of Yellowstone National Park, and
      • Improvements to lake, meteorological, and hydrological monitoring to better track hydrothermal activity, including that occurring on lake bottoms, and to aid in understanding of whether such activity might be influenced by external forces, like environmental conditions.

      The 2022–2032 monitoring plan for the Yellowstone volcanic system also proposes to improve monitoring of hydrothermal areas to better understand these dynamic systems and their associated hazards. To date, only a single seismometer has been placed within one of Yellowstone National Park’s geyser basins because seismic noise associated with boiling water can hinder interpretation of overall seismic and magmatic activity, but this concern has been mitigated by improvements to backbone monitoring. Deployment of geophysical, geochemical, hydrological, and geological monitoring instruments in geyser basins will be accompanied by campaigns to measure gas and water chemistry and flux, as well as aerial and satellite surveys of gas and thermal emissions.

      Close collaboration between YVO member institutions and other research agencies is needed to achieve these monitoring goals and to use the derived data to advance understanding of how Yellowstone Caldera and similar volcanic systems work. At the same time, attention must be paid to minimize the impact of monitoring efforts and infrastructure on the environment. YVO thus commits to serving as stewards of the natural, cultural, and historical resources in and around Yellowstone National Park while maximizing scientific gain for the betterment of society.

      DLR Earth Sensing Imaging Spectrometer (DESIS) level 1 product evaluation using RadCalNet measurements

      Released June 21, 2022 06:47 EST

      2021, Remote Sensing (13)

      Mahesh Shrestha, Dennis Helder, Jon Christopherson

      The DLR Earth Sensing Imaging Spectrometer (DESIS) is the first hyperspectral imaging spectrometer installed in the Multi-User System for Earth Sensing (MUSES) on the International Space Station (ISS) for acquiring routine science grade images from orbit. It was launched on 29 June 2018 and integrated into MUSES. DESIS measures energy in the spectral range of 400 to 1000 nm with high spatial and spectral resolution: 30 m and 2.55 nm, respectively. DESIS data should be sufficiently quantitative and accurate to use it for different applications and research. This work performs a radiometric evaluation of DESIS Level 1 product (Top of Atmosphere (TOA) reflectance) by comparing it with coincident Radiometric Calibration Network (RadCalNet) measurements at Railroad Valley Playa (RVUS), Gobabeb (GONA), and La Crau (LCFR). RVUS, GONA, and LCFR offer 4, 15, and 5 coincident datasets between DESIS and RadCalNet measurements, respectively. The results show an agreement between DESIS and RadCalNet TOA reflectance within ~5% for most spectral regions. However, there is an additional ~5% disagreement across the wavelengths affected by water vapor absorption and atmospheric scattering. Among the three RadCalNet sites, RVUS and GONA show a similar measurement disagreement with DESIS of ~5%, while LCFR differs by ~10%. Agreement between DESIS and RadCalNet measurements is variable across all three sites, likely due to surface type differences. DESIS and RadCalNet agreement show a precision of ~2.5%, 4%, and 7% at RVUS, GONA, and LCFR, respectively. RVUS and GONA, which have a similar surface type, sand, have a similar level of radiometric accuracy and precision, whereas LCFR, which consists of sparse vegetation, has lower accuracy and precision. The observed precision of DESIS Level 1 products from all the sites, especially LCFR, can be improved with a better Bidirectional Reflection Distribution Function (BRDF) characterization of the RadCalNet sites.

      Animal movement models with mechanistic selection functions

      Released June 20, 2022 15:05 EST

      2020, Spatial Statistics (37)

      Mevin Hooten, Xinyi Lu, Martha J. Garlick, James A. Powell

      A suite of statistical methods are used to study animal movement. Most of these methods treat animal trajectory data in one of three ways: as discrete pro- cesses, as continuous processes, or as point processes. We brie y review each of these approaches and then focus in on the latter. In the context of point processes, so-called resource selection analyses are among the most common way to statis- tically treat animal trajectory data. However, most resource selection analyses provide inference based on approximations of point process models. The forms of these models have been limited to a few types of specications that provide infer- ence about relative resource use and, less commonly, probability of use. For more general spatio-temporal point process models, the most common type of analysis often proceeds with a data augmentation approach that is used to create a binary data set that can be analyzed with conditional logistic regression. We show that the conditional logistic regression likelihood can be generalized to accommodate a variety of alternative specications related to resource selection. We then provide an example of a case where a spatio-temporal point process model coincides with that implied by a mechanistic model for movement expressed as a partial dier- ential equation derived from rst principles of movement. We demonstrate that inference from this form of point process model is intuitive (and could be useful for management and conservation) by analyzing a set of telemetry data from a mountain lion in Colorado, USA, to understand the eects of spatially explicit environmental conditions on movement behavior of this species.

      Evaluating the paleoenvironmental significance of sediment grain size in Bering Sea sediments during Marine Isotope Stage 11

      Released June 20, 2022 11:54 EST

      2022, Stratigraphy (19) 119-139

      Natalie Thompson, Beth Elaine Caissie

      Grain size is an important textural property of sediments and is widely used in paleoenvironmental studies as a means to infer changes in the sedimentary environment. However, grain size parameters are not always easy to interpret without a full understanding of the factors that influence grain size. Here, we measure grain size in sediment cores from the Bering slope and the Umnak Plateau, and review the effectiveness of different grain size parameters as proxies for sediment transport, current strength, and primary productivity, during a past warm interval (Marine Isotope Stage 11, 424-374 ka). In general, sediments in the Bering Sea are hemipelagic, making them ideal deposits for paleoenvironmental reconstructions, but there is strong evidence in the grain size distribution for contourite deposits between ~408-400 ka at the slope sites, suggesting a change in bottom current transport at this time. We show that the grain size of coarse (>150 µm) terrigenous sediment can be used effectively as a proxy for ice rafting, although it is not possible to distinguish between iceberg and sea ice rafting processes, based on grain size alone. We find that the mean grain size of bulk sediments can be used to infer changes in productivity on glacial-interglacial timescales, but the size and preservation of diatom valves also exert a control on mean grain size. Lastly, we show that the mean size of sortable silt (10-63 µm) is not a valid proxy for bottom current strength in the Bering Sea, because the input of ice-rafted silt confounds the sortable silt signal.

      Predictive models of phosphorus concentration and load in stormwater runoff from small urban residential watersheds in fall season

      Released June 20, 2022 11:04 EST

      2022, Journal of Environmental Management (315)

      Yi Wang, Anita Thompson, William R. Selbig

      Urban street trees are a key part of public green infrastructure in many cities, however, leaf litter on streets is a critical biogenic source of phosphorus (P) in urban stormwater runoff during Fall. This study identified mass of street leaf litter (Mleaf) and antecedent dry days (ADD) as the top two explanatory parameters that have significant predictive power of event end-of-pipe P concentrations through multiple linear regression (MLR) analysis. Mleaf and volume of runoff (Vol) were the top two key explanatory parameters of event end-of-pipe P loads. Two-predictor MLR models were developed with these explanatory parameters using a 40-storm dataset derived from six small urban residential watersheds in Wisconsin, USA, and evaluated using storms specific to each study basin. The MLR model validation results indicated sensitivity to storm composition in the datasets. Our analysis shows selected parameters can be used by environmental managers to facilitate end-of-pipe P prediction in urban areas. This information can be used to reduce the amount of P in stormwater runoff by adjusting the timing and frequency of municipal leaf collection and street cleaning programs in urban areas.

      Demonstration of a novel quantitative microscopy technique for automated characterization of in situ particulate matter in coal miners with progressive massive fibrosis

      Released June 20, 2022 10:55 EST

      2022, Conference Paper, American Thoracic Society 2022 proceedings

      Jeremy Hua, L. Zell-Baran, L. H. Go, C. Cool, Heather A. Lowers, K. S. Almberg, E. Sarver, S Majka, K. Pang, R. A. Cohen, C.S. Rose

      Rationale: Increasing exposure to respirable crystalline silica (RCS) linked to changes in mining production processes has been implicated in the resurgence of severe lung disease in U.S. coal miners. Lung mineralogy can provide insight into particle pathogenesis. However, standard approaches to characterizing in situ particulate matter (PM) by pulmonary pathologists have poor inter-rater comparability, and consensus agreement is time consuming. Scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDX) is technically complex and labor intensive. We developed a method for quantitative in situ PM characterization using conventional polarized light microscopy (PLM) and explored PM features in lung tissue of coal miners with progressive massive fibrosis (PMF). Methods: With institutional review board approval, PLM images were obtained from 30 miners with PMF, classified by pathologists consensus based on PM profusion; 10 from each profusion group (mild/moderate/severe) were selected. Automated PM counting and characterization (including dimensions and grayscale intensity of PM > 0.3 m diameter) was performed on image samples using PLM with modified cell-counting software (BZ-X800 light microscope, Keyence Corporation, Osaka, Japan) (Figure 1). Quantitative PM density loge(PM count)/mm3 tissue was calculated for each sample and compared to pathologist PM profusion groups. PMF lesion type using consensus pathologist classification (13 coal-type, 9 mixed-type, and 8 silicotic-type) was compared to automated PM birefringence level (% particles with mean grayscale intensity <65, range 0-255). RCS particles are expected to be weakly birefringent (lower intensity) relative to other common minerals (e.g., silicates) contained in coal mine dust. PM features were analyzed in R 4.0.3 using one-way ANOVA for between-group comparisons. Results: Measured PM log-density increased significantly with higher qualitative profusion group (mild=10.480.98/mm3, moderate=11.460.81/mm3, severe=12.520.86/mm3, p<0.0001). Prevalence of weakly birefringent particles was significantly higher among silicotic-type PMF samples (31.57.9%) compared to either coal-type (21.510.1%, p=0.022) or mixed-type lesions (21.510.5%, p=0.025). Conclusion: This pilot study demonstrates the feasibility of a novel quantitative microscopy technique for counting and characterizing in situ lung PM in coal miners with PMF. Quantitative PM burden was comparable to pulmonary pathologists consensus profusion classification, but this method was substantially less time consuming and labor intensive and provided additional information about relevant PM features. The higher prevalence of weakly birefringent particles seen in silicotic-type PMF lesions may help inform mineralogic pathogenesis of RCS. Future efforts will expand the number of PMF cases analyzed, further validate our mineralogic findings using data from SEM/EDX and lung tissue digestate methods, and compare findings in historical versus contemporary coal miners with PMF.

      Assessing runoff and erosion on woodland-encroached sagebrush steppe using the Rangeland Hydrology and Erosion Model

      Released June 19, 2022 11:00 EST

      2022, Ecosphere (13)

      C. Jason Williams, Frederick B. Pierson, Osama Z. Al-Hamdan, S. Kossi Nouwakpo, Justin C. Johnson, Viktor O. Polyakov, Patrick R. Kormos, Scott Shaff, Kenneth E. Spaeth

      The transition of sagebrush-dominated (Artemisia spp.) shrublands to pinyon (Pinus spp.) and juniper (Juniperus spp.) woodlands markedly alters resource-conserving vegetation structure typical of these landscapes. Land managers and scientists in the western United States need knowledge and predictive tools for assessment and effective targeting of tree-removal treatments to conserve or restore sagebrush vegetation and associated hydrologic function. This study developed modeling approaches to quantify the hydrologic vulnerability and erosion potential of sagebrush rangelands in the later stages of woodland encroachment and in response to commonly applied tree-removal treatments. Using experimental data from multiple sites in the Great Basin Region, USA, and process-based knowledge from decade-long vegetation and rainfall simulation studies at those sites, we (1) assessed the capability of the Rangeland Hydrology and Erosion Model (RHEM) to accurately predict patch-scale (12 m2) measured runoff and erosion from tree canopy and intercanopy hydrologic functional units in untreated and burned woodlands 9 years postfire, and (2) developed and evaluated multiple RHEM approaches/frameworks to model aggregated effects of tree canopy and intercanopy areas on patch- and hillslope-scale (50 m length) runoff and erosion processes in untreated and treated (burned, cut, and masticated) woodlands. The RHEM accurately predicted measured runoff and sediment yield from patch-scale rainfall simulations as partitioned on untreated and treated tree canopy and intercanopy areas and effectively parameterized the dominant controls on runoff and erosion process in woodlands. With few exceptions, evaluated hillslope-scale RHEM frameworks similarly predicted reduced hydrologic vulnerability and erosion potential for conditions 9 years following tree removal by burning, cutting, and mastication treatments. Regressions of RHEM-predicted hillslope runoff, sediment, and hydraulic/erosion parameters with bare ground and ground cover attributes indicate all RHEM frameworks effectively represented the dominant controls on hydrologic and erosion processes for rangelands and woodlands. The results provide RHEM frameworks and recommendations for assessing hydrologic vulnerability and erosion potential on woodland-encroached sites and predicting the effectiveness of tree removal to reestablish a water and soil resource-conserving vegetation structure on sagebrush rangelands. We anticipate our RHEM or similar modeling approaches may be applicable to analogous water-limited landscapes elsewhere subject to woody plant encroachment.

      What is a biocrust? A refined, contemporary definition for a broadening research community

      Released June 18, 2022 11:20 EST

      2022, Biological Reviews

      Bettina Weber, Jayne Belnap, Burkhard Büdel, Anita J. Antoninka, Nichole N. Barger, V Bala Chaudhary, Anthony Darrouzet-Nardi, David J. Eldridge, Akasha M. Faist, Scott Ferrenberg, Caroline Havrilla, Elisabeth Huber-Sannwald, Oumarou Malam Issa, Fernando T. Maestre, Sasha Reed, Emilio Rodriguez-Caballero, Colin L Tucker, Kristina E Young, Yuanming Zhang, Yunge Zhao, Xiaobing Zhou, Matthew A. Bowker

      Studies of biological soil crusts (biocrusts) have proliferated over the last few decades. The biocrust literature has broadened, with more studies assessing and describing the function of a variety of biocrust communities in a broad range of biomes and habitats and across a large spectrum of disciplines, and also by the incorporation of biocrusts into global perspectives and biogeochemical models. As the number of biocrust researchers increases, along with the scope of soil communities defined as ‘biocrust’, it is worth asking whether we all share a clear, universal, and fully articulated definition of what constitutes a biocrust. In this review, we synthesize the literature with the views of new and experienced biocrust researchers, to provide a refined and fully elaborated definition of biocrusts. In doing so, we illustrate the ecological relevance and ecosystem services provided by them. We demonstrate that biocrusts are defined by four distinct elements: physical structure, functional characteristics, habitat, and taxonomic composition. We describe outgroups, which have some, but not all, of the characteristics necessary to be fully consistent with our definition and thus would not be considered biocrusts. We also summarize the wide variety of different types of communities that fall under our definition of biocrusts, in the process of highlighting their global distribution. Finally, we suggest the universal use of the Belnap, Büdel & Lange definition, with minor modifications: Biological soil crusts (biocrusts) result from an intimate association between soil particles and differing proportions of photoautotrophic (e.g. cyanobacteriaalgaelichensbryophytes) and heterotrophic (e.g. bacteriafungiarchaea) organismswhich live withinor immediately on top ofthe uppermost millimetres of soil. Soil particles are aggregated through the presence and activity of these often extremotolerant biota that desiccate regularlyand the resultant living crust covers the surface of the ground as a coherent layer. With this detailed definition of biocrusts, illustrating their ecological functions and widespread distribution, we hope to stimulate interest in biocrust research and inform various stakeholders (e.g. land managers, land users) on their overall importance to ecosystem and Earth system functioning.

      Application of a soil-water-balance model to estimate annual groundwater recharge for Long Island, New York, 1900–2019

      Released June 17, 2022 10:44 EST

      2022, Scientific Investigations Report 2021-5143

      Jason S. Finkelstein, Jack Monti Jr., John P. Masterson, Donald A. Walter

      A soil-water-balance (SWB) model was developed for Long Island, New York, to estimate the potential amount of annual groundwater recharge to the Long Island aquifer system from 1900 to 2019. The SWB model program is a computer code based on a modified Thornthwaite-Mather SWB approach and uses spatially and temporally distributed meteorological, land-cover, and soil properties as input to compute potential daily groundwater recharge. Simulated outputs indicate that island-wide potential groundwater recharge trends, as a percentage of precipitation, have increased approximately 3 percent during the 120-year period. The simulated results account for both climatic and land-cover changes that have occurred during the period. A change from undeveloped (forested land cover) to low- and medium-density residential land cover or land use increased potential groundwater recharge because of a decrease in evapotranspiration. During the 30-year period from 1900 to 1930, the simulated potential average groundwater recharge rate on Long Island was estimated to be 18.50 inches per year (in/yr), or a total of 1,243 million gallons per day, during the 30-year period from 1985 to 2015, the simulated potential average groundwater recharge rate estimate increased to 20.73 in/yr (a total of around 1,393 million gallons per day).

      During the 1900–2019 simulation period, the potential average annual groundwater recharge rate was about 19.24 in/yr. The data for that period included values for a 3-year meteorological drought from 1963 to 1965, where the mean precipitation was about 26.5 percent lower than the long-term average of 46.7 in/yr, and the potential groundwater recharge rate was about 12.3 in/yr. During a 3-year wet period from 1982 to 1984, where mean precipitation was about 19.6 percent higher than the long-term average, the estimated potential groundwater recharge rate was about 26.8 in/yr.

      The measurement of adenosine triphosphate in pure algal cultures and natural aquatic samples

      Released June 17, 2022 09:52 EST

      1976, Journal of Research of the U.S. Geological Survey (4) 241-245

      W. T. Shoaf, Bruce W. Lium

      Three methods for the extraction of adenosine triphosphate (ATP) neutral dimethyl sulfoxide (DMSO), boiling tris buffer, and butanol-octanol extraction were equally effective on the alga Chlorella vulgwia. Dilution of extracted ATP samples was linear. Filtration of different volumes of samples resulted in proportional values for ATP in the extracts. Measurement of activity by either peak height or integration of the area under the peak were equally sensitive and reproducible. The assay of ATP sample was inhibited by mercuric chloride > cadmium chloride > calcium chloride > potassium or sodium phosphate, and by high concentrations of the extractant DMSO. Analysis of ATP in aquatic environments led to the problem of transferring a sample from the field to the laboratory without obtaining a change in ATP concentration. Membrane filtration of the sample followed by chilling at 4°C, slow freezing at 20° C, or freezing on dry ice were ineffective in maintaining a constant level of ATP. Chilling caused a marked increase in ATP, whereas slow freezing caused a significant loss of ATP. Freezing on dry ice was variable but generally resulted in large losses of ATP. Quick freezing by immersion of filter and algae in liquid nitrogen and storage on dry ice maintained a constant ATP level. Field extraction of the ATP followed by quick freezing in an acetone-dry-ice bath maintained the ATP in a convenient and stable form.

      Primary production responses to extreme changes in North American Monsoon precipitation vary by elevation and plant functional composition through time

      Released June 17, 2022 09:17 EST

      2022, Journal of Ecology

      Seth M. Munson, John Bradford, Bradley J. Butterfield, Jennifer R. Gremer

      1. Primary production in dryland ecosystems is limited by water availability and projected to be strongly affected by future shifts in seasonal precipitation. Warm-season precipitation derived from the North American Monsoon contributes 40% of annual precipitation to dryland ecosystems in the southwestern U.S. and is projected to become more variable. However, there is large uncertainty on whether this variability will be expressed as either extreme wet or dry years and how primary production of different plant functional types will respond across widespread elevation gradients in this region.
      2. We experimentally imposed extreme drought and water addition treatments from 2016 – 2020, during which ambient warm-season precipitation declined to reach historic lows, to understand production sensitivity of dominant plant functional types along a 1,000 m elevation gradient.
      3. We found that the production responses of plant functional types to monsoon precipitation extremes were dependent on the number of treatment years that occurred across sites along the elevation gradient. C4 perennial grasses were most responsive to precipitation manipulation treatments, followed by C3 perennial grasses and annuals, while perennial forbs and shrubs had weak or no responses. C4 perennial grass reductions due to extreme drought were generally stronger or occurred earlier at low elevation sites, while multi-year extreme drought extended negative effects to C3 perennial grasses at high elevation, and all sites showed delayed responses to multi-year water addition. We found that the sensitivity of C3 perennial grass production differed for extreme drought and water addition compared to ambient precipitation at one site, but other sites and plant functional types had similar sensitivities to the different treatment types.
      4. Synthesis. The upward advance of primary production responsiveness from single- to multi-year extreme changes in warm-season precipitation suggests more immediate shifts in functional composition and carbon cycling at low elevation, while high elevation ecosystems may become less resistant as the effects of extreme precipitation compound through time.

      Resisting-accepting-directing: Ecosystem management guided by an ecological resilience assessment

      Released June 17, 2022 08:52 EST

      2022, Environmental Management

      Kristen L. Bouska, Nathan R. De Jager, Jeffrey N. Houser

      As anthropogenic influences push ecosystems past tipping points and into new regimes, complex management decisions are complicated by rapid ecosystem changes that may be difficult to reverse. For managers who grapple with how to manage ecosystems under novel conditions and heightened uncertainty, advancing our understanding of regime shifts is paramount. As part of an ecological resilience assessment, researchers and managers have collaborated to identify alternate regimes and build an understanding of the thresholds and factors that govern regime shifts in the Upper Mississippi River System. To describe the management implications of our assessment, we integrate our findings with a recently developed framework that explicitly acknowledges ecosystem regime change and outlines management approaches of resisting change, accepting change, or directing change. More specifically, we developed guidance for using knowledge of desirability of current conditions, distance to thresholds, and general resilience (that is, an ecosystem’s capacity to cope with uncertain disturbances) to navigate the resist-accept-direct (RAD) framework. We applied this guidance to outline strategies that resist, accept, or direct change in the context of management of aquatic vegetation, floodplain vegetation, and fish communities across nearly 2000 river kilometers. We provide a case study for how knowledge of ecological dynamics can aid in assessing which management approach(es) are likely to be most ecologically feasible in a changing world. Continued learning from management decisions will be critical to advance our understanding of how ecosystems respond and inform the management of ecosystems for desirable and resilient outcomes.

      Data-driven modeling of wind waves in upper Delaware Bay with living shorelines

      Released June 17, 2022 08:36 EST

      2022, Ocean Engineering (257)

      Nan Wang, Qin Chen, Ling Zhu, Hongqing Wang

      Living shoreline projects have been built to preserve coastal ecosystems under future climate change and sea level rise. To quantify the wave power variation across living shorelines, the wave characteristics around the constructed oyster reefs (CORs) in upper Delaware Bay were investigated in this study. Wave parameters seaward and shoreward of CORs were recorded by wave gauges in early 2018. Four winter storms happened in this period and induced strong winds and coastal flooding at the study site. To estimate the wind wave characteristics across the CORs on a yearly basis, soft computing-based models combining fully connected neural networks and long short-term memory were developed to extend the two-month energetic wave measurements. The results show that when CORs were emergent or slightly submerged, the averaged wave height attenuation was about 39.8% from the offshore gauge to the nearshore gauge (behind CORs) during 2018–2020, owing to the combined effect of nearshore bathymetric changes and CORs. Furthermore, it was found that the annually averaged wave power reduction from offshore to nearshore at the study site was about 30.0% in 2018, 2019, and 2020. This study provides a novel framework to predict long-term wave characteristics based on short-term wave measurements using soft computing-based models.

      Assessing wave attenuation with rising sea levels for sustainable oyster reef-based living shorelines

      Released June 17, 2022 07:39 EST

      2022, Frontiers in Built Environment (8)

      Reza Salatin, Hongqing Wang, Qin Chen, Ling Zhu

      In densely populated coastal areas with sea-level rise (SLR), protecting the shorelines against erosion due to the wave impact is crucial. Along with many engineered structures like seawalls and breakwaters, there are also green structures like constructed oyster reefs (CORs) that can not only attenuate the incident waves but also grow and maintain pace with SLR. However, there is a lack of data and understanding of the long-term wave attenuation capacity of the living shoreline structures under SLR. In this study, we used the phase-resolving Boussinesq model, FUNWAVE-TVD, to examine the hydrodynamics including wave height and wave-induced currents around the CORs in the Gandys Beach living shoreline project area in the upper Delaware Bay, United States. Waves were measured at six locations (offshore to onshore, with and without CORs) in the Gandys Beach living shoreline project area for two winter months, during which four nor’easters occurred. We selected three cases that represent prevailing wind, wave, and tide conditions to examine the fine spatial and temporal changes in wave height and current velocity by the construction of the reefs. Wave heights and wave energy spectra generated from FUNWAVE-TVD were then validated with field observations. It is found that FUNWAVE-TVD is capable of simulating waves and associated hydrodynamic processes that interact with CORs. The model results show that wave attenuation rates vary with the incident wave properties and water depth, and wave-induced circulation patterns are affected by the CORs. The wave attenuation capacity of CORs over the next 100 years was simulated with the incorporation of the oyster reef optimal growth zone. Our study found that sustainable wave attenuation capacity can only be achieved when suitable habitat for COR is provided, thus it can vertically grow with SLR. Suitable habitat includes optimal intertidal inundation duration, current velocity for larval transport and settlement, on-reef oyster survival and growth, and other environmental conditions including salinity, temperature, and nutrient availability. Furthermore, the model results suggest that it would take CORs approximately 9 years after construction to reach and maintain the maximum wave attenuation capacity in sustainable living shorelines.

      Assessment of streamflow trends in the eastern Dakotas, water years 1960–2019

      Released June 17, 2022 07:23 EST

      2022, Scientific Investigations Report 2022-5055

      Parker A. Norton, Gregory C. Delzer, Joshua F. Valder, Wyatt S. Tatge, Karen R. Ryberg

      Hydrologic extremes, whether periods of drought or flooding, are occurring more frequently with greater severity and can have substantial economic impacts. Along with flooding, the timing and volume of streamflow also is changing across the United States. The focus of this report is to characterize a unique trend in mean annual streamflow occurring in eastern North and South Dakota, hereafter referred to as the eastern Dakotas, that is not being observed anywhere else in the conterminous United States.

      Streamflow records for 1,853 U.S. Geological Survey streamgages obtained from the U.S. Geological Survey National Water Information System database with a continuous record of mean annual streamflow during water years 1960–2019 were included in this study. Using a Kendall tau statistical test (p-value less than or equal to 0.10), 573 streamgages had a statistically significant upward trend in mean annual streamflow and are primarily located in the Midwest and northeastern United States. Of the streamgages, 182 had a statistically significant downward trend and are located primarily in the western and southeastern States. Several sites had increases in streamflow between 100 and 500 percent. Most of the streamgages with the highest increases in mean annual streamflow are along the same rivers in the eastern Dakotas, regardless of basin size.

      A comparison of mean annual streamflow of the last decade (2010–19) to the first decade (1960–69) of the study period shows that the largest increases in annual streamflow volumes in the United States also are in the eastern Dakotas. Among all 1,853 streamgages in the United States, the Sheyenne River near Warwick, North Dakota (U.S. Geological Survey station 05056000), has the greatest percent change, with an increase of 486 percent. Several factors may be contributing to increasing trends in streamflow in the eastern Dakotas and may include, in part, precipitation changes owing to climatic variation within the region, geologic makeup of the subsurface, and land-use changes. A better understanding of these research areas will help producers, resource managers, and infrastructure engineers to make more informed environmental and economic decisions.

      Hidden in plain sight: Migration routes of the elusive Anadyr bar-tailed godwit revealed by satellite tracking

      Released June 16, 2022 11:53 EST

      2022, Journal of Avian Biology

      Ying-Chi Chan, T. Lee Tibbitts, Dmitry Dorofeev, Chris J. Hassell, Theunis Piersma

      Satellite and GPS tracking technology continues to reveal new migration patterns of birds which enables comparative studies of migration strategies and distributional information useful in conservation. Bar-tailed godwits in the East Asian–Australasian Flyway Limosa lapponica baueri and L. l. menzbieri are known for their long non-stop flights, however these populations are in steep decline. A third subspecies in this flyway, L. l. anadyrensis, breeds in the Anadyr River basin, Chukotka, Russia, and is morphologically distinct from menzbieri and baueri based on comparison of museum specimens collected from breeding areas. However, the non-breeding distribution, migration route and population size of anadyrensis are entirely unknown. Among 24 female bar-tailed godwits tracked in 2015–2018 from northwest Australia, the main non-breeding area for menzbieri, two birds migrated further east than the rest to breed in the Anadyr River basin, i.e. they belonged to the anadyrensis subspecies. During pre-breeding migration, all birds staged in the Yellow Sea and then flew to the breeding grounds in the eastern Russian Arctic. After breeding, these two birds migrated southwestward to stage in Russia on the Kamchatka Peninsula and on Sakhalin Island en route to the Yellow Sea. This contrasts with the other 22 tracked godwits that followed the previously described route of menzbieri, i.e. they all migrated northwards to stage in the New Siberian Islands before turning south towards the Yellow Sea, and onwards to northwest Australia. Since the Kamchatka Peninsula was not used by any of the tracked menzbieri birds, the 4500 godwits counted in the Khairusova–Belogolovaya estuary in western Kamchatka may well be anadyrensis. Comparing migration patterns across the three bar-tailed godwits subspecies, the migration strategy of anadyrensis lies between that of menzbieri and baueri. Future investigations combining migration tracks with genomic data could reveal how differences in migration routines are evolved and maintained.

      Highly pathogenic avian influenza (HPAI): An emerging disease threat in North America

      Released June 16, 2022 09:32 EST

      2022, Report

      Andrew M. Ramey, Colleen M. Handel

      Highly pathogenic avian influenza (HPAI) is an ecologically and economically significant avian disease that is quickly spreading among wild and domestic birds throughout North America. In this blog post, we provide information and resources that can help you to be informed, be prepared, and be ready to take appropriate action should you observe wild birds that may be affected by HPAI.

      A refined assessment of the paleoceanographic and tectonic influences on the deposition of the Monterey Formation in California

      Released June 16, 2022 09:14 EST

      2022, Book chapter, Understanding the Monterey Formation and similar biosiliceous units across space and time

      John A. Barron

      Ivano Aiello, John A. Barron, Christina Ravelo, editor(s)

      Application of updated diatom biochronology to the Monterey Formation and related biosiliceous rocks reveals the imprint of both global paleoclimatic/ paleoceanographic and regional tectonic events. A rise in global sea level combined with regional tectonic deepening associated with the development of the transform California margin resulted in the abrupt onset of deposition of fine-grained Monterey sediments between 18 and 16 Ma. The base of the Monterey does not mark a silica shift in diatom deposition from the North Atlantic to the North Pacific. Rather, a North Atlantic decline of diatoms after ~13 Ma and increasing divergence in nutrient levels between the North Atlantic and North Pacific between ~13 and 11 Ma, coincided with a major enhancement of diatom deposition in the Monterey Formation. A stratigraphically condensed interval of phosphate-rich sediments between 13 and 10 Ma in coastal southern California appears to have resulted from sediment starvation on offshore banks during a period of higher sea level, as inland sections commonly contain thick sequences of diatomaceous sediment. Increasing latitudinal thermal gradients in the latest Miocene, which triggered a biogenic bloom in the equatorial Pacific at 8 Ma, also lead to enhanced diatom deposition in the uppermost Monterey and overlying biosiliceous rocks. Uplift of the California coastal ranges after ~5.2 Ma resulted in an increasing detrital contribution that obscured the presence of diatoms in onshore sediments. Major reduction in coastal upwelling in the early Pliocene at ~4.6 Ma caused a drastic reduction of diatoms in sediments of offshore southern California.

      Enumerating plausible multifault ruptures in complex fault systems with physical constraints

      Released June 16, 2022 09:04 EST

      2022, Bulletin of the Seismological Society of America

      Kevin R. Milner, Bruce E. Shaw, Edward H. Field

      We propose a new model for determining the set of plausible multifault ruptures in an interconnected fault system. We improve upon the rules used in the Third Uniform California Earthquake Rupture Forecast (UCERF3) to increase connectivity and the physical consistency of ruptures. We replace UCERF3’s simple azimuth change rules with new Coulomb favorability metrics and increase the maximum jump distance to 15 km. Although the UCERF3 rules were appropriate for faults with similar rakes, the Coulomb calculations used here inherently encode preferred orientations between faults with different rakes. Our new rules are designed to be insensitive to discretization details and are generally more permissive than their UCERF3 counterparts; they allow more than twice the connectivity compared to UCERF3, yet heavily penalize long ruptures that take multiple improbable jumps. The set of all possible multifault ruptures in the California fault system is near-infinite, but our model produces a tractable set of 326,707 ruptures (a modest 29% increase over UCERF3, despite the greatly increased connectivity). Inclusion in the rupture set does not dictate that a rupture receives a significant rate in the final model; rupture rates are subsequently determined by data constraints used in an inversion. We describe the rupture building algorithm and its components in detail and provide comparisons with ruptures generated by a physics-based multicycle earthquake simulator. We find that greater than twice as many ruptures generated by the simulator violate the UCERF3 rules than violate our proposed model.

      Mapping a magnetic superstorm: March 1989 geoelectric hazards and impacts on United States power systems

      Released June 16, 2022 08:55 EST

      2022, Space Weather (20)

      Jeffrey J. Love, Greg M. Lucas, E. Joshua Rigler, Benjamin Scott Murphy, Anna Kelbert, Paul A. Bedrosian

      A study is made of the relationships between geomagnetic and geoelectric field variation, Earth-surface impedance, and operational interference (anomalies) experienced on electric-power systems across the contiguous United States during the March 13-14, 1989 magnetic storm. For this, a 1-minute-resolution sequence of geomagnetic field maps is constructed from magnetometer time series acquired at ground-based observatories. Induced geoelectric field maps are calculated by convolving the geomagnetic maps with magnetotelluric impedance tensors. During the storm, anomalies were concentrated where the lithosphere is electrically resistive, and when and where geoelectric field amplitudes were high. This was particularly true in the Mid-Atlantic, Northeast, and the upper Midwest. Few anomalies were experienced in other parts of the Midwest and across much of the West, where the lithosphere is more conductive, and when and where geoelectric field amplitudes were low. Peak 1-minute-resolution geoelectric field amplitude ranged from 21.66 V/km in Maine and 19.02 V/km in Virginia to < 0.02 V/km in Idaho. Latitude-dependent organization of geoelectric hazards by auroral-zone electrojet currents is detectable, but it is much weaker than geographic organization due to surface impedance. Hazardous geoelectric fields were induced during different storm phases, at different local times, and, by inference, by a variety of ionospheric currents. Compared to geoelectric field amplitudes realized across the United States during March 1989, hazard maps used by utility companies to estimate systems exposure have much less geographic detail and a much smaller maximum-to-minimum range in geoelectric field amplitude. Future research will benet from denser geomagnetic monitoring, additional magnetotelluric surveying, and access to power-system impact data.

      The heat capacities at low temperatures and entropies at 298.15 K of low albite, analbite, microline, and high sanidine

      Released June 15, 2022 11:22 EST

      1976, Journal of Research of the U.S. Geological Survey (4) 204

      R. E. Openshaw, Bruce S. Hemingway, Richard A. Robie, David R. Waldbaum, K. M. Krupka

      The heat capacities of low albite and analbite, NaAlSi3O8, and of microcline and high sanidine, KAlSi3Og, have been measured from 15 to 375 K using an adiabatic calorimeter. Tables of the thermodynamic functions p, (H°T–H°0)/T, (G°T–H°0)/T, andT–S°0 are presented for these four feldspars from 0 to 370 K. At 298.15 K (25.0°C) the values for S°T0 for low albite, analbite, microcline, and high sanidine are 207.4±0.4, 207.7±0.4, 214.2±0.4, and 214.2±0.4 J/(mol.K), respectively.

      The effect of the state of Al/Si order upon the heat capacity is quite small. The difference, ΔC°p, between albite-analbite and microcline-sanidine never exceeds 0.5 percent at temperatures below 400 K.

      With the exception of microcline, the heat capacities of these four feldspars follow a smooth S-shaped curve between 15 and 375 K, with no indication of transitions or anomalous behavior. Above 250 K, the heat capacity of microcline shows a form of thermal hysteresis. In the temperature range 250 to 375 K, the heat capacity of microcline is dependent upon its past thermal history. At 375 K, microcline which had been cooled to 230 K before the measurement of p has a heat capacity greater by approximately 1.2 percent than microcline which had not been previously cooled below 295 K. After a day of annealing at about 300 K, p of the previously cooled microcline decreases to essentially the same value as the microcline which had never been at a temperature below 300 K.

      The consequences of climate change for dryland biogeochemistry

      Released June 15, 2022 07:20 EST

      2022, New Phytologist Foundation

      Brooke Bossert Osborne, Brandon T. Bestelmeyer, Courtney M. Currier, Peter M Homyak, Heather L. Throop, Kristina E Young, Sasha Reed

      Drylands, which cover more than 40% of Earth’s terrestrial surface, are dominant drivers of global biogeochemical cycling and home to more than one third of the human population. Climate projections predict warming, drought frequency and severity, and evaporative demand will increase in drylands at faster rates than global means. Due to extreme temperatures and high biological dependency on limited water availability, drylands are predicted to be exceptionally sensitive to climate change and, indeed, significant climate impacts are already being observed. Yet our understanding and ability to forecast climate change effects on dryland biogeochemistry and ecosystem functions lag behind many mesic systems. To improve our capacity to forecast ecosystem change, we propose focusing on the controls and consequences of two key characteristics affecting dryland biogeochemistry: i) high spatial and temporal heterogeneity in environmental conditions and ii) generalized resource scarcity. In addition to climate change, drylands are experiencing accelerating land use change. Building our understanding of dryland biogeochemistry in both intact and disturbed systems will better equip us to address the interacting effects of climate change and landscape degradation. Responding to these challenges will require a diverse, globally distributed, and interdisciplinary community of dryland experts united towards better understanding these vast and important ecosystems.

      Implementation plan of the National Cooperative Geologic Mapping Program strategy — Appalachian Piedmont and Blue Ridge Provinces

      Released June 14, 2022 17:20 EST

      2022, Open-File Report 2022-1050

      Arthur J. Merschat, Mark W. Carter, 2018 Piedmont and Blue Ridge Working Group

      The National Cooperative Geologic Mapping Program is publishing a strategic plan titled “Renewing the National Cooperative Geologic Mapping Program as the Nation’s Authoritative Source for Modern Geologic Knowledge.” The plan provides a vision, mission, and goals for the program for the years 2020–30:

      • Vision: create an integrated, three-dimensional, digital geologic map of the United States.
      • Mission: characterize, interpret, and disseminate a national geologic framework model of the Earth through geologic mapping.
      • Goal: focus on geological mapping as a core function of the U.S. Geological Survey within the long-term vision of adequately mapping the Nation’s geologic framework in three dimensions.

      Opportunities to improve alignment with the FAIR Principles for U.S. Geological Survey data

      Released June 14, 2022 14:20 EST

      2022, Open-File Report 2022-1043

      Frances L. Lightsom, Vivian B. Hutchison, Bradley Bishop, Linda M. Debrewer, David L. Govoni, Natalie Latysh, Shelley Stall

      In 2016, an interdisciplinary, international group of 53 scientists introduced a framework named “the FAIR Principles” for addressing 21st century scientific data challenges. The FAIR Principles are increasingly used as a guide for producing digital scientific products that are findable, accessible, interoperable, and reusable (FAIR), especially to enable use of such products in automated systems. Data aligned with the FAIR Principles can increase the efficiency of science integration capabilities such as those envisioned for the U.S. Geological Survey (USGS) Earth Monitoring, Analyses, and Projections (EarthMAP) initiative.

      The FAIR Principles clearly define the characteristics of reusable scientific products, but it is less clear how to facilitate consistency in achieving these characteristics across the Bureau. USGS data are produced by local research projects distributed over more than 100 centers in 7 regions. After data are approved for release, they could be managed in numerous repositories and online data systems. The diversity of USGS data is illustrated by the topical range of the USGS mission areas: Core Science Systems, Ecosystems, Energy and Minerals, Natural Hazards, and Water Resources. In the USGS context, realizing the EarthMAP vision for automated, predictive, integrated science that provides timely and actionable results involves providing knowledge and support services and developing the skills, infrastructure, and culture to enable Bureau-wide implementation of the FAIR Principles.

      In 2019, the USGS Community for Data Integration funded a project to convene a broadly representative workshop and produce recommendations to enable consistency with the FAIR Principles across the USGS. The workshop, held in Fort Collins, Colorado, in September 2019, brought together 28 participants for 3 days to engage with the FAIR Principles, analyze USGS use cases, and discuss the roles of data producers and managers, data storage and catalogs, value-added services, and policy makers in implementing the FAIR Principles. Workshop participants agreed that scientific reproducibility requires the extension of the FAIR Principles beyond measured data to include physical samples, research methods, software, and tools at the USGS. Workshop discussions focused on how the USGS can implement the FAIR Principles by supporting research teams in creating data, metadata, and other scientific products and also by supporting enterprise systems that maintain and leverage the products’ consistency with the FAIR Principles.

      The resulting FAIR roadmap of recommendations describes nine proposed interdependent strategies that could be achieved by coordinated actions taken by different parts of the USGS. A proposed early action would be the creation of a coordinating council that includes representatives from the groups engaged in activities consistent with better alignment with the FAIR Principles. The nine proposed strategies, which are presented in more detail in this roadmap report, focus on enabling improvements to individual data products, providing infrastructure, and structuring administrative activities to support an organizational culture that values the FAIR Principles.

      Arkansas and Landsat

      Released June 14, 2022 09:25 EST

      2022, Fact Sheet 2022-3042

      U.S. Geological Survey

      Scenic Arkansas certainly lives up to its nickname, “The Natural State.” The Ozark Plateau and Ouachita Mountains boast stunning views, vast resources, and recreation. Hardwood and pine forests cover one-half of the State. The major rivers—Arkansas, Ouachita, Red, and White—offer recreation and navigation as they drain toward the Mississippi River, which forms the State’s eastern border. Smaller streams and rivers, reservoirs, and rice fields serve as homes for wildlife as well, including birds migrating along the Mississippi Flyway.

      Agriculture has always been a key industry in Arkansas, which is the top rice producer in the United States. Poultry, soybeans, cotton, cattle, and timber are among other agricultural products that contribute to the State’s economy. The aquaculture industry has diversified from just goldfish to more than 20 species of fish and crustaceans.

      Geological features include waterfalls, limestone caves, and the country’s only active diamond mine, Crater of Diamonds State Park, where visitors can keep any rock or mineral they find in the volcanic crater. Hot Springs National Park—within the city of Hot Springs—features thermal springs of water heated deep belowground that follow a fault line of the Ouachita Mountains up to the surface.

      Here are a few ways Landsat has benefited Arkansas.

      A haploid pseudo-chromosome genome assembly for a keystone sagebrush species of western North American rangelands

      Released June 13, 2022 11:17 EST

      2022, G3 Genes, Genomes, Genetics

      Anthony E. Melton, Andrew W. Child, Richard S. Beard Jr., Carlos Dave C. Dumaguit, Jennifer S. Forbey, Matthew Germino, Marie-Anne de Graaff, Andrew Kliskey, Ilia J. Leitch, Peggy Martinez, Stephen J. Novak, Jaume Pellicer, Bryce A. Richardson, Desiree Self, Marcelo D. Serpe, Sven Buerki

      Increased ecological disturbances, species invasions, and climate change are creating severe conservation problems for several plant species that are widespread and foundational. Understanding the genetic diversity of these species and how it relates to adaptation to these stressors are necessary for guiding conservation and restoration efforts. This need is particularly acute for big sagebrush (Artemisia tridentata; Asteraceae), which was once the dominant shrub over 1,000,000 km2 in western North America but has since retracted by half and thus has become the target of one of the largest restoration seeding efforts globally. Here, we present the first reference-quality genome assembly for an ecologically important subspecies of big sagebrush (A. tridentata subsp. tridentata) based on short and long reads, as well as chromatin proximity ligation data analyzed using the HiRise pipeline. The final 4.2-Gb assembly consists of 5,492 scaffolds, with nine pseudo-chromosomal scaffolds (nine scaffolds comprising at least 90% of the assembled genome; n =9). The assembly contains an estimated 43,377 genes based on ab initio gene discovery and transcriptional data analyzed using the MAKER pipeline, with 91.37% of BUSCOs being completely assembled. The final assembly was highly repetitive, with repeat elements comprising 77.99% of the genome, making the Artemisia tridentata subsp. tridentata genome one of the most highly repetitive plant genomes to be sequenced and assembled. This genome assembly advances studies on plant adaptation to drought and heat stress and provides a valuable tool for future genomic research.

      How do accuracy and model agreement vary with versioning, scale, and landscape heterogeneity for satellite-derived vegetation maps in sagebrush steppe?

      Released June 13, 2022 11:00 EST

      2022, Ecological Indicators (139)

      Cara Applestein, Matthew J. Germino

      Maps of the distribution and abundance of dominant plants derived from satellite data are essential for ecological research and management, particularly in the vast semiarid shrub-steppe. Appropriate application of these maps requires an understanding of model accuracy and precision, and how it might vary across space, time, and different vegetation types. For a 113 k Ha burn area, we compared modeled maps of different vegetation cover types created from satellite data to ‘benchmark” models based on intensive field sampling (~1500-2000 plots resampled annually for 5 years) for three new satellite-derived models: USDA Rangeland Analysis Platform (RAP), the USGS Rangeland Condition Monitoring Assessment and Projection (RCMAP), and USGS fractional estimate of exotic annual grass cover (USGS-fractional-EAG). We assessed out-of-sample point accuracy and asked if and how accuracy changed each year due to vegetation shifts, new images, and model improvements (i.e. model versions). We also assessed how map agreement between satellite-based and field-based models changed with scale of application, topography, and time since fire.

      Accuracy and map agreement varied considerably among the vegetation types and across time and space (r2 ranging from 0 to 0.53), and some of the variability was predictable. All models tended to over or underestimate cover when field-measured cover was relatively low or high, respectively, i.e. a “false moderating effect”. Accuracy was greater and improved with newer versions of RAP (+0.05 to 0.29 r2) compared to RCMAP and USGS fractional model estimates, and in some cases was greater than field-based models. Variability in map agreement tended to decrease with larger areas sampled (particularly in areas >12 km), and this scale dependency was more evident in RAP and USGS-fractional-EAG models. Creating a “fair” basis for comparison of spatial models of low-statured semiarid vegetation derived from satellite compared to field data is not trivial because scaling the field data to the scale of large satellite pixels (or downscaling satellite-based models to field scale) requires modeling and associated model uncertainty. Accuracy can vary considerably and understanding the variation can help guide application of the models to the appropriate time, place, and variables.

      Thirteen novel ideas and underutilized resources to support progress towards a range-wide American eel stock assessment

      Released June 13, 2022 10:49 EST

      2022, Fisheries Management and Ecology

      David K. Cairns, José Benchetrit, Louis Bernatchez, Virginie Bornarel, John M. Casselman, Martin Castonguay, Anthony Charsley, Malte Dorrow, Hilaire Drouineau, Jens Frankowski, Alexander Haro, Simon Hoyle, D. Craig Knickle, Marten A. Koops, Luke A. Poirier, James T. Thorson, John A. Young, Xinhua Zhu

      A robust assessment of the American eel (Anguilla rostrata) stock, required to guide conservation efforts, is challenged by the species’ vast range, high variability in demographic parameters and data inadequacies. Novel ideas and underutilised resources that may assist both analytic assessments and spatially oriented modelling include (1) species and environmental databases; (2) mining of data from scattered sources; (3) infilling of data gaps by spatial analysis; (4) age estimation from measurements of DNA methylation; evaluation of eel abundance by (5) larval, (6) glass-bottom boat, (7) net enclosure and (8) eDNA surveys; (9) accounting for dam-induced habitat increases in eel watercourse modelling; (10) spatially oriented modelling with and without temporal components; (11) geographically nested modelling of glass eel recruitment; (12) spawner per recruit modelling and (13) life cycle modelling to examine larval allocation effects. Eel biologists are too few to gather the required assessment data across all of the species’ range. Public posting of electrofishing and eDNA metabarcoding data sets and the use of machine learning techniques to comprehensively inventory small dams will help meet some data needs. These approaches address only a small proportion of the assessment challenges that face American eels. Worldwide collaboration amongst Anguilla scientists is a key enabler of progress towards stock assessment goals.

      Quantifying relations between altered hydrology and fish community responses for streams in Minnesota

      Released June 13, 2022 10:45 EST

      2022, Ecological Processes (11)

      Jeffrey R. Ziegeweid, Gregory D. Johnson, Aliesha L. Krall, Kara Fitzpatrick, Sara B. Levin

      Altered hydrology is a stressor on aquatic life for several streams in Minnesota, but quantitative relations between specific aspects of streamflow alteration and biological responses have not been developed on a statewide scale in Minnesota. Best subsets regression analysis was used to develop linear regression models that quantify relations among five categories of hydrologic explanatory metrics (i.e., duration, frequency, magnitude, rate-of-change, and timing) computed from streamgage records and six categories of biological response metrics (i.e., composition, habitat, life history, reproductive, tolerance, trophic) computed from fish community samples, as well as fish-based indices of biotic integrity (FIBI) scores and FIBI scores normalized to the an impairment threshold of the corresponding stream class (FIBI_BCG4). Three hydrologic datasets were used to examine rRelations between altered hydrology and fish community responses were examined at three different temporal scalesusing three hydrologic datasets that represented periods of record, long-term changes, and short-term changes to flow regimes in streams of Minnesota.

      Dammed water quality — Longitudinal stream responses below beaver ponds in the Umpqua River Basin, Oregon

      Released June 13, 2022 10:43 EST

      2022, Ecohydrology

      John R. Stevenson, Jason B. Dunham, Steve M. Wondzell, Jimmy D. Taylor

      Beaver-related restoration (BRR) has gained popularity as a means of improving stream ecosystems, but the effects are not fully understood. Studies of dissolved oxygen (DO) and water temperature, key water quality metrics for salmonids, have demonstrated improved conditions in some cases, but warming and decreased DO have been more commonly reported in meta-analyses. These results point to the contingencies that can influence outcomes from BRR. We examined water quality related to beaver ponds in a diverse coastal watershed (Umpqua River Basin, OR, USA). We monitored water temperature 0–400 m above and below beaver ponds and at pond surfaces and bottoms across seven study sites from June through September of 2019. DO was also recorded at two sites at pond surfaces and pond bottoms. Downstream monthly mean daily maximum temperatures were warmer than upstream reference locations by up to 1.9°C at beaver dam outlets but this heating signal attenuated with downstream distance. Downstream warming was greatest in June and July and best predicted by pond bottom temperatures. DO at pond surfaces and bottoms were hypoxic (≤5 mg/L) for more than half of the 32-day monitoring period. Water temperatures increased for short distances below monitored beaver ponds and observed oxygen conditions within ponds were largely unsuitable for salmonid fishes. These findings contrast with some commonly stated expectations of BRR, and we recommend that managers consider these expectations prior to implementation. In some cases, project goals may override water quality concerns but in streams where temperature or DO restoration are objectives, managers may consider using BRR techniques with caution.

      Spectral mixture analysis for surveillance of harmful algal blooms (SMASH): A field-, laboratory-, and satellite-based approach to identifying cyanobacteria genera from remotely sensed data

      Released June 13, 2022 10:31 EST

      2022, Remote Sensing of Environment (279)

      Carl J. Legleiter, Tyler Victor King, Kurt Carpenter, Natalie Celeste Hall, Adam Mumford, E. Terrence Slonecker, Jennifer L. Graham, Victoria G. Stengel, Nancy Simon, Barry H. Rosen

      Algal blooms around the world are increasing in frequency and severity, often with the possibility of adverse effects on human and ecosystem health. The health and economic impacts associated with harmful algal blooms, or HABs, provide compelling rationale for developing new methods for monitoring these events via remote sensing. Although concentrations of chlorophyll-a and key pigments like phycocyanin are routinely estimated from satellite images and used to infer algal or cyanobacterial cell counts, current methods are unable to provide information on the taxonomic composition of a bloom. This study introduced a new approach capable of differentiating among genera based on their reflectance characteristics: Spectral Mixture Analysis for Surveillance of HABs, or SMASH. The foundation of SMASH is a multiple endmember spectral mixture analysis (MESMA) algorithm that takes a library of cyanobacteria endmembers and a hyperspectral image as input and estimates the fractional abundance of each genus, plus water, on a per-pixel basis. Importantly, we assume that the water column consists of only pure water and cyanobacteria, implying that our linear spectral unmixing models do not account for other optically active constituents such as suspended sediment and colored dissolved organic matter (CDOM). We used reflectance spectra for 12 genera measured under a microscope to populate an algal spectral library and applied the SMASH workflow to satellite images from four waterbodies across the United States. Normalized spectral separability scores indicated that the 12 genera were distinct from one another and the MESMA algorithm reproduced known input fractions for simulated mixtures that included all pairwise combinations of genera and water. We used Upper Klamath Lake as an example to illustrate data products generated via SMASH: maps of the normalized difference chlorophyll index and cyanobacterial index, a MESMA-based classification of algal genera, fraction images for each endmember, and a root mean square error (RMSE) image that summarizes uncertainty. For Upper Klamath Lake, these outputs highlighted a complex algal bloom featuring several genera, primarily Aphanizomenon, and intricate spatial patterns associated with gyres. The maximum RMSE constraint imposed on the MESMA algorithm provided a means of avoiding false positive detection of genera not present in a waterbody but must not be set so low as to leave much of an image unclassified in cases where genera included in the library are present. Comparison of endmember fractions with relative biovolumes calculated from field samples indicated that taxonomic information from SMASH was consistent with field observations. For example, the algorithm successfully identified Microcystis in Owasco Lake but avoided misclassifying Asterionella, a genus not yet included in our library, in Detroit Lake. This proof-of-concept investigation demonstrates the potential of SMASH to enhance our understanding of algal blooms, particularly with respect to their spatial and temporal dynamics.


      Management and environmental factors associated with simulated restoration seeding barriers in sagebrush steppe

      Released June 13, 2022 10:30 EST

      2022, Restoration Ecology

      Stella M. Copeland, John Bradford, Stuart P. Hardegree, Daniel Rodolphe Schlaepfer, Kevin J Badik

      Adverse weather conditions, particularly freezing or drought, are often associated with poor seedling establishment following restoration seeding in drylands like the Great Basin sagebrush steppe (USA). Management decisions such as planting date or seed source could improve restoration outcomes by reducing seedling exposure to weather barriers. We simulated the effects of management and environmental factors on seedling exposure to post-germination barriers for bottlebrush squirreltail (Elymus elymoides), Sandberg bluegrass (Poa secunda), and bluebunch wheatgrass (Pseudoroegneria spicata). We combined germination timing models with daily soil moisture and temperature estimates to calculate yearly germination favorability and post-germination freezing and drought barriers for three planting dates (Oct. 15, Nov. 15, and Mar. 15) and three seed sources or cultivars per species for 5000 sites in each of 40 yrs (water years 1980-2019). We tested the effects of site environmental variables (elevation, mean annual precipitation, heat load, and clay content) and management choices (seed source and planting date) on germination favorability and barrier occurrence (mean) and variability (coefficient of variation). Seedling exposure to barriers was strongly linked to management decisions in addition to site mean precipitation and elevation. Later fall plantings and seed sources with slower germination (lower mean germination favorability) were less likely to encounter freezing and drought barriers. These results suggest that management actions can play a role comparable to site environmental variables in reducing exposure of vulnerable seedlings to adverse weather conditions and subsequent effects on restoration outcomes.

      Tree regrowth duration map from LCMAP collection 1.0 land cover products in the conterminous United States, 1985–2017

      Released June 13, 2022 09:23 EST

      2022, GIScience & Remote Sensing (59) 959-974

      Qiang Zhou, George Z. Xian, Josephine Horton, Danika F. Wellington, Grant Domke, Roger F. Auch, Congcong Li, Zhe Zhu

      Forest covers about one-third of the land area of the conterminous United States (CONUS) and plays an important role in offsetting carbon emissions and supporting local economies. Growing interest in forests as relatively cost-effective nature-based climate solutions, particularly restoration and reforestation activities, has increased the demand for information on forest regrowth and recovery following natural and anthropogenic disturbances (e.g., fire, harvest, or thinning). However, a wall-to-wall mapping of the CONUS tree regrowth duration at an annual time interval and 30-m resolution is still challenging. In this study, we utilized the annual land cover products to develop a dataset to quantify forest regrowth duration for CONUS over 1985–2017. The land cover data used to derive the tree regrowth duration map is from the primary land cover product in the U.S. Geological Survey’s Land Change Monitoring, Assessment, and Projection (LCMAP) collection. The LCMAP product used all available Landsat images to detect disturbances over forest and classify Grass/Shrub to Tree Cover transitions on an annual basis. The average regrowth duration was then calculated for each pixel. The regrowth duration map was validated using human interpreted annual reference data that were collected independently. The validation results show one-year of underestimation and 6-year standard deviation of error between the reference data and regrowth duration map. In southeastern CONUS, where major tree regrowth activities have been observed, our map showed higher accuracy with less than one-year bias and 3.6 years standard deviation of error. Forest in the southeast took around 5 years to recover, which was faster than other regions of CONUS. Many pixels had multiple disturbances during the 33-year study period in the region. The spatial pattern of the tree regrowth indicated intense harvesting activities in this region. The Pacific Northwest coast region was the second main area of tree regrowth, but this region often took multiple decades to recover. Given increasing interest in forests as nature-based climate solutions, the tree regrowth duration map can be used to assess reforestation activities as well as forest recovery following natural disturbance and harvesting.

      Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019

      Released June 13, 2022 07:24 EST

      2022, Water Resources Research (58)

      Roy Petrakis, Christopher E. Soulard, Eric K. Waller, Jessica J. Walker

      Satellite imagery is commonly used to map surface water extents over time, but many approaches yield discontinuous records resulting from cloud obstruction or image archive gaps. We applied the Dynamic Surface Water Extent (DSWE) model to downscaled (250-m) daily Moderate Resolution Imaging Spectroradiometer (MODIS) data in Google Earth Engine to generate monthly surface water maps for the conterminous United States (US) from 2003 through 2019. The aggregation of daily observations to monthly maps of maximum water extent produced records with diminished cloud and cloud shadow effects across most of the country. We used the continuous monthly record to analyze spatiotemporal surface water trends stratified within Environmental Protection Agency Ecoregions. Although not all ecoregion trends were significant (p < 0.05), results indicate that much of the western and eastern US underwent a decline in surface water over the 17-year period, while many ecoregions in the Great Plains had positive trends. Trends were also generated from monthly streamgage discharge records and compared to surface water trends from the same ecoregion. These approaches agreed on the directionality of trend detected for 54 of 85 ecoregions, particularly across the Great Plains and portions of the western US, whereas trends were not congruent in select western deserts, the Great Lakes region, and the southeastern US. By describing the geographic distribution of surface water over time and comparing these records to instrumented discharge data across the conterminous US, our findings demonstrate the efficacy of using satellite imagery to monitor surface water dynamics and supplement traditional instrumented monitoring.

      Predicting near-term effects of climate change on nitrogen transport to Chesapeake Bay

      Released June 12, 2022 09:12 EST

      2022, Journal of the American Water Resources Association

      Scott Ator, Gregory E. Schwarz, Andrew Sekellick, Gopal Bhatt

      Understanding effects of climate change on nitrogen fate and transport in the environment is critical to nutrient management. We used climate projections within a previously calibrated spatially referenced regression (SPARROW) model to predict effects of expected climate change over 1995 through 2025 on total nitrogen fluxes to Chesapeake Bay and in watershed streams. Assuming nitrogen inputs and other watershed conditions remain at 2012 levels, effects of increasing temperature, runoff, streamflow, and stream velocity expected between 1995 and 2025 will include an estimated net 6.5% decline in annual nitrogen delivery to the bay from its watershed. This predicted decline is attributable to declines in the delivery of nitrogen from upland nonpoint sources to streams due to predicted warmer temperatures. Such temperature-driven declines in the delivery of nitrogen to streams more than offset predicted increased delivery to and within streams due to increased runoff and streamflow and may be attributable to increasing rates of denitrification or ammonia volatilization or to changes in plant phenology. Predicted climate-driven declines in nitrogen flux are generally similar across the watershed but vary slightly among major nonpoint source sectors and tributary watersheds. Nitrogen contributions to the bay from point sources are not affected by temperature-driven changes in delivery from uplands and are therefore predicted to increase slightly between 1995 and 2025.

      ECCOE Landsat Quarterly Calibration and Validation report— Quarter 4, 2021

      Released June 10, 2022 07:10 EST

      2022, Open-File Report 2022-1033

      Md Obaidul Haque, Rajagopalan Rengarajan, Mark Lubke, Fatima Tuz Zafrin Tuli, Jerad L. Shaw, Md Nahid Hasan, Alex Denevan, Shannon Franks, Esad Micijevic, Michael J. Choate, Cody Anderson, Brian Markham, Kurt Thome, Ed Kaita, Julia Barsi, Raviv Levy, Lawrence Ong

      Executive Summary

      The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Calibration and Validation (Cal/Val) Center of Excellence (ECCOE) focuses on improving the accuracy, precision, calibration, and product quality of remote-sensing data, leveraging years of multiscale optical system geometric and radiometric calibration and characterization experience. The ECCOE Landsat Cal/Val Team continually monitors the geometric and radiometric performance of active Landsat missions and makes calibration adjustments, as needed, to maintain data quality at the highest level.

      This report provides observed geometric and radiometric analysis results for Landsats 7–8 for quarter 4 (October–December), 2021. All data used to compile the Cal/Val analysis results presented in this report are freely available from the USGS EarthExplorer website: https://earthexplorer.usgs.gov.

      One specific activity that the Cal/Val Team continued to closely monitor this quarter was the Landsat 8 Thermal Infrared Sensor (TIRS) response degradation, which has been observed since the two November 2020 safehold events. Detailed analysis results characterizing this degradation have been included in this report. Additional information about the safehold events is here: https://www.usgs.gov/core-science-systems/nli/landsat/november-19-2020-landsat-8-data-availability-update-recent-safehold.

      Belowground mutualisms to support prairie reconstruction—Improving prairie habitat using mycorrhizal inoculum

      Released June 09, 2022 13:18 EST

      2022, Open-File Report 2022-1055

      Stefanie N. Vink, Laura Aldrich-Wolfe, Sheri C. Huerd, Jennifer L Larson, Sara C. Vacek, Pauline M. Drobney, Marsha Barnes, Karen Viste-Sparkman, Nicholas R. Jordan, Diane L. Larson

      As a first step toward understanding the feasibility of using arbuscular mycorrhizal fungi (AMF) in reconstruction practice, we addressed four objectives: (1) compare root-associated AMF communities of plants between high-quality remnant prairies and reconstructed prairies, (2) compare root-associated AMF communities between plant species that declined in reconstructions and species that were thriving, (3) compare AMF communities collected from roots of plants in geographically separate parts of Minnesota and Iowa, and (4) assess the relationship between AMF communities and soil abiotic factors. We collected soil and root samples in 8 prairies reconstructed in 2005 (and monitored through 2015) and 6 remnant prairies, and the samples were separated into 6 geographically determined clusters, each containing 1–2 reconstructions and 1 remnant. Sequencing was completed on 1,188 deoxyribonucleic acid extracts from individual plant root samples, and fungal sequences were clustered to operational taxonomic units at 97-percent identity. Nonmetric multidimensional scaling was used to visualize differences in species composition of AMF communities among plant species and field sites. Permutational analysis of variance was completed to test for differences in AMF community composition between the 2 types of sites (remnants and reconstructions), among plant species, and among the 6 site clusters. AMF communities differed between remnant and reconstructed prairies, with one exception, and AMF associated with individual plant species also tended to differ, depending on whether the plant species’ roots were collected from remnant or reconstructed prairie. On the other hand, we did not determine that, as a group, species in decline in the reconstructions we had monitored were more likely to harbor different AMF communities compared to species not in decline in the reconstructions. Significant interactions between site type and clusters indicate geographic variation in AMF communities. Total carbon and nitrogen, and organic matter, were higher in remnant soils, whereas phosphorus, which at high concentrations reduces the value of AMF to plants, was much higher in soils collected from reconstructions.

      A lesser scaup (Aythya affinis ) naturally infected with Eurasian 2.3.4.4 highly pathogenic H5N1 avian influenza virus – Movement ecology and host factors

      Released June 09, 2022 09:23 EST

      2022, Transboundary and Emerging Diseases

      Diann Prosser, Hannah Schley, Nathan Simmons, Jeffery D Sullivan, Josh Homyack, Matthew M. Weegman, Glenn H. Olsen, Alicia Berlin, Rebecca L. Poulson, David E. Stallknecht, Christopher K. Williams

      Despite the recognized role of wild waterfowl in the potential dispersal and transmission of highly pathogenic avian influenza (HPAI) virus, little is known about how infection affects these birds. This lack of information limits our ability to estimate viral spread in the event of an HPAI outbreak, thereby limiting our abilities to estimate and communicate risk. Here we present telemetry data from a wild Lesser Scaup (Aythya affinis), captured during a separate ecology study in the Chesapeake Bay, Maryland. This bird tested positive for infection with clade 2.3.4.4 HPAI virus of the A/goose/Guangdong/1/1996 (Gs/GD) H5N1 lineage (results received post-release) during the 2021–22 ongoing outbreaks in North America. While the infected bird was somewhat lighter than other adult males surgically implanted with transmitters (790g, ߂ = 868g, n = 11), it showed no clinical signs of infection at capture, during surgery, nor upon release. The bird died 3d later, pathology undetermined as the specimen was not able to be recovered. Analysis of movement data within the 3d window showed that the infected individual's maximum and average hourly movements (3894.3m, 428.8m respectively) were noticeably lower than noninfected conspecifics tagged and released the same day (߂ = 21594.5m, ߂ = 1097.9m, respectively; n = 4). We identified four instances where the infected bird had close contact (fixes located within 25m and 15 min) with another marked bird during this time. Collectively, these data suggest that the HPAI positive bird observed in this study may have been shedding virus for some period prior to death, with opportunities for direct bird to bird or environmental transmission. Although limited by low sample size and proximity to the time of tagging, we hope that these data will provide useful information as managers continue to respond to this ongoing outbreak event.

      Migration of first-year steppe eagles (Aquila nipalensis) from northern Kazakhstan and implications for conservation

      Released June 09, 2022 09:19 EST

      2022, Conference Paper, Biological diversity of Asian steppes

      Todd E. Katzner, R. Efrat, A. E. Bragin, Y. Lehnardt, E. A. Bragin, N. Sapir

      Extensive anthropogenic alteration of steppe ecosystems throughout Eurasia leaves central Asia with some of the world’s last remaining large expanses of grassland habitat. Steppe eagles (Aquila nipalensis) are globally endangered breed primarily in these steppe ecosystems. We evaluated migratory movements of first year steppe eagles hatched in northern Kazakhstan, to understand their migration and the extent to which their movements expose them to threats that may impact population viability. Most steppe eagles we monitored migrated to the east of the Caspian Sea to wintering grounds on the Arabian Peninsula or northeastern Africa, although a few migrated to the west of the Caspian Sea, one wintered in southcentral Iran, and one in southern Pakistan. Northbound migration routes largely mirrored southbound routes. Straight-line distance between summering and wintering grounds averaged 3,582 km (fall) and 3,700 km (spring), and actual distance traveled averaged 7,183 km (fall) and 9,433 km (spring). Routes of travel of these steppe eagles expose them to potential electrocution, shooting, and wildlife trade across the extent of their migratory and wintering areas.

      Turbidity and estimated phosphorus retention in a reconnected Lake Erie coastal wetland

      Released June 09, 2022 09:05 EST

      2022, Water (14)

      Glenn Carter, Kurt P. Kowalski, Michael Eggleston

      Nearly all of the wetlands in the coastal zone of Lake Erie have been degraded or destroyed since the 1860s, and most of those that remain are separated from their watersheds by earthen dikes. Hydrologic isolation of these wetlands disrupts ecosystem benefits typical to Great Lakes coastal wetlands, particularly the ability to trap sediments and retain nutrients when inundated by runoff and lake water. High-frequency measurements of turbidity and discharge were taken in 2013 and 2014 to observe turbidity and water flow dynamics to estimate total phosphorus flux of a hydrologically reconnected diked wetland pool in the Crane Creek-Lake Erie wetland complex. Modeled estimates suggest the reconnected pool retained 8% of the total phosphorus loading in 2013 and 10% in 2014, which included short periods of phosphorus export to Lake Erie. Water flowing out of the wetland generally had lower turbidity than inflowing water, but flux in and out of the pool varied seasonally and was linked to changes in lake-levels, seiche dynamics, and weather conditions. More frequent storms, higher winds, and stronger seiches in the spring and fall created turbidity patterns that suggest more phosphorus retention than in summer or winter. Estimates suggest that phosphorus was released during the summer when higher lake levels and the absence of frequent storms, larger short-term seiche oscillations, and potentially soil oxygen availability were driving flux dynamics. This study demonstrated that reestablishing lake hydrology through reconnection of wetland pools can reduce loading and alter timing of delivery of total phosphorus to Lake Erie.

      Interannual variation in climate contributes to contingency in post-fire restoration outcomes in seeded sagebrush steppe

      Released June 09, 2022 08:19 EST

      2022, Conservation Science and Practice

      Allison Barbara Simler-Williamson, Cara Applestein, Matthew Germino

      Interannual variation, especially weather, is an often-cited reason for restoration “failures”; yet its importance is difficult to experimentally isolate across broad spatiotemporal extents, due to correlations between weather and site characteristics. We examined post-fire treatments within sagebrush-steppe ecosystems to ask: (1) Is weather following seeding efforts a primary reason why restoration outcomes depart from predictions? and (2) Does the management-relevance of weather differ across space and with time since treatment? Our analysis quantified range-wide patterns of sagebrush (Artemisia spp.) recovery, by integrating long-term records of restoration and annual vegetation cover estimates from satellite imagery following thousands of post-fire seeding treatments from 1984 to 2005. Across the Great Basin, sagebrush growth increased in wetter, cooler springs; however, the importance of spring weather varied with sites' long-term climates, suggesting differing ecophysiological limitations across sagebrush's range. Incorporation of spring weather, including from the “planting year,” improved predictions of sagebrush recovery, but these advances were small compared to contributions of time-invariant site characteristics. Given extreme weather conditions threatening this ecosystem, explicit consideration of weather could improve the allocation of management resources, such as by identifying areas requiring repeated treatments; but improved forecasts of shifting mean conditions with climate change may more significantly aid the prediction of sagebrush recovery.

      Montana and Landsat

      Released June 08, 2022 14:59 EST

      2022, Fact Sheet 2022-3041

      U.S. Geological Survey

      The landscapes beneath Montana’s big sky are as breathtaking as the State’s nickname would suggest. Visitors to the 41st State's "Big Sky Country" can take in the stunning icy hues of aquamarine at Glacier National Park; explore the northern swaths of Yellowstone National Park; or hike, bike, or boat through Bighorn Canyon National Recreation Area, and those are just the National parks.

      Montana is the fourth-largest State by land area, with miles upon miles of forests, rolling prairie rangelands, croplands, badlands, and mountains, from which flow a sizable part of the Nation’s water supply. The headwaters of the Missouri River, which covers 2,341 miles before merging with the Mississippi River, are located in Three Forks, Montana. On the opposite side of the Continental Divide, the Kootenai, Clark Fork, Blackfoot, Bitterroot, and Flathead Rivers flow across Montana and into the Columbia River, which ultimately empties into the Pacific Ocean.

      The Treasure State’s cherished landscapes face many threats, however: fire-fueling invasive grasses, increasing temperatures caused by climate change, shifting land use patterns, water supply contractions, and more. The U.S. Geological Survey Landsat satellite program’s imagery can improve Montanans’ understanding of land change and offer valuable insight for the ranchers, farmers, land and resource managers, firefighters, and urban planners.

      The role of pH up-regulation in response to nutrient-enriched, low-pH groundwater discharge

      Released June 08, 2022 08:58 EST

      2022, Marine Chemistry (243)

      Nancy G. Prouty, Marlene Wall, J. Fietzke, Olivia Cheriton, Eleni Anagnostou, Brian Phillip, Adina Paytan

      Coral reefs and their ecosystems are threatened by both global stressors, including increasing sea-surface temperatures and ocean acidification (OA), and local stressors such as land-based sources of pollution that can magnify the effects of OA. Corals can physiologically control the chemistry of their internal calcifying fluids (CF) and can thereby regulate their calcification process. Specifically, increasing aragonite saturation state in the CF (ΩCF) may allow corals to calcify even under external low saturation conditions. Questions remain regarding the physiological processes that govern the CF chemistry and how they change in response to multiple stressors. To address this knowledge gap, the boron δ11B and B/Ca were analyzed in tropical corals, Porites lobata, collected at submarine groundwater seeps impacted by the release of treated wastewater in west Maui, Hawai'i, to document the interactions between high nutrient / low pH seep water on CF carbonate chemistry. Results show substantial up-regulation of pH and dissolved inorganic carbon (DIC) with respect to seawater in P. lobata corals collected from within the wastewater impacted area at Kahekili Beach Park compared to the control site at Olowalu Beach. The ΩCF was 9 to 10 times higher than ambient seawater Ω, and 13 to 26% higher than in corals from the control site and from values previously observed in tropical Porites spp. corals. Such elevated up-regulation suggests that corals exposed to nutrient-enriched, low pH effluent sustain CF supersaturated with respect to aragonite, possibly as an internal coping mechanism to combat multiple stressors from land-based sources of pollution. This elevated up-regulation has implications to coral vulnerability to future climate- and ocean-change.

      Dynamic rating method for computing discharge from time-series stage data

      Released June 08, 2022 08:55 EST

      2022, Open-File Report 2022-1031

      Marian M. Domanski, Robert R. Holmes Jr., Elizabeth N. Heal

      Ratings are used for a variety of reasons in water-resources investigations. The simplest rating relates discharge to the stage of the river. From a pure hydrodynamics perspective, all rivers and streams have some form of hysteresis in the relation between stage and discharge because of unsteady flow as a flood wave passes. Simple ratings are unable to represent hysteresis in a stage/discharge relation. A dynamic rating method is capable of capturing hysteresis owing to the variable energy slope caused by unsteady momentum and pressure.

      A dynamic rating method developed to compute discharge from stage for compact channel geometry, referred to as DYNMOD, previously has been developed through a simplification of the one-dimensional Saint-Venant equations. A dynamic rating method, which accommodates compound and compact channel geometry, referred to as DYNPOUND, has been developed through a similar simplification as a part of this study. The DYNMOD and DYNPOUND methods were implemented in the Python programming language. Discharge time series computed with the dynamic rating method implementations were then compared to simulated discharge time series and discrete discharge measurements made at U.S. Geological Survey streamgage sites.

      Four sets of stage and discharge time series were created using one-dimensional unsteady simulation software with compound channel geometry to compare the results of both dynamic rating methods to results from the full one-dimensional shallow water equations. Discharge time series were computed from stage time series using DYNMOD and DYNPOUND. DYNPOUND outperformed DYNMOD in all four scenarios. The minimum and maximum mean squared logarithmic error (MSLE) for the DYNMOD results were 2.75×10−2 and 3.40×10−2, respectively. The minimum and maximum MSLE for the DYNPOUND results were 2.51×10−7 and 1.91×10−4, respectively.

      The dynamic rating methods were calibrated for six U.S. Geological Survey streamgage sites using observed discharge data collected at the sites. The calibration objective for each site was to minimize the MSLE of the discharge computed with the rating method with respect to observed discharge. For each site, the calibration included all field measurements within a selected water year. The DYNMOD method failed to compute discharge for the full calibration time series for three sites. A method fails to compute when the implementation returns a nonfinite value at a time step. Because the values computed for following time steps are dependent on the previous time step, a nonfinite value results in nonfinite values that follow. For the three sites for which DYNMOD computed the complete discharge time series, the minimum MSLE for calibration was 2.19×10−3 and the maximum was 9.77×10−3. The MSLE of the DYNPOUND computed discharge calibration time series for the six sites ranged from 3.70×10−3 to 1.25. For each site, an event-based time period was selected to compare the discharge time series computed with the dynamic rating methods to discrete discharge field measurements made at the streamgage sites. The DYNMOD-computed discharge time series for the three sites had an MSLE range of 2.76×10−3 to 3.14×10−2. The range of MSLE for the six DYNPOUND sites was 3.64×10−3 to 7.23×10−2. Although the DYNMOD method outperforms the DYNPOUND method when calibrated streamgage sites are under consideration, the DYNMOD method failed to compute a discharge time series at three of the six sites. The DYNPOUND method, therefore, was more robust than the DYNMOD method. Improvements to the implementation of the DYNPOUND method may improve the accuracy of the method.

      Distinct pathways to stakeholder use versus academic contribution in climate adaptation research

      Released June 08, 2022 08:47 EST

      2022, Conservation Letters

      Amanda A Hyman, Stephanie Courtney, Karen S McNeal, Lalasia Bialic-Murphy, Cari Furiness, Mitchell Eaton, Paul A Armsworth

      Challenges facing societies around the globe as they plan for and adapt to climate change are so large that usable, research-driven recommendations to inform management actions are urgently needed. We sought to understand factors that influence the variation of academic contribution and use of collaborative research on climate change. We surveyed researchers (n = 31), program-leaders (n = 5), and stakeholders (n = 81) from projects supported by a federally funded network across the United States. Our results suggest that peer-reviewed publications do not lead to use, but frequency of meetings with stakeholders significantly increased use. Overall, the factors needed for projects to have high degrees of academic contributions are distinct from those needed to be useful to stakeholders. Furthermore, leadership perceptions of use of projects were significantly different from users. Our quantitative results can inform future requests for proposals and better enable researchers using collaborative approaches to conduct science that is more often used by stakeholders.

      Water storage decisions and consumptive use may constrain ecosystem management under severe sustained drought

      Released June 08, 2022 07:45 EST

      2022, Journal of the American Water Resources Association

      Lindsey Ann Bruckerhoff, Kevin Wheeler, Kimberly L. Dibble, B.A. Mihalevich, B.T. Nielson, J. Wang, Charles Yackulic, J.C. Schmidt

      Drought has impacted the Colorado River basin for the past 20 years and is predicted to continue. In response, decisions about how much water should be stored in large reservoirs and how much water can be consumptively used will be necessary. These decisions have the potential to limit riverine ecosystem management options through the effect water-supply decisions have on reservoir elevations. We used projected hydrology and river temperatures to compare the outcome of combinations of water storage scenarios and consumptive use limits on metrics associated with ecosystem management of the Colorado River in Grand Canyon. Ecosystem management metrics included the ability to implement designer flows, temperature suitability for fishes, and fragmentation. We compared current water management operations to prioritizing storage in either Lake Mead or Lake Powell combined with three levels of consumptive use. Projected reservoir levels limited environmental flow delivery and increased fragmentation regardless of where water was stored if consumptive use was not limited. Warmer river temperatures associated with low reservoir levels are likely, creating suitable conditions for non-native species of concern, such as smallmouth bass. Water storage decisions provided variability and management flexibility, but water storage was less important when less water was available, highlighting the importance of keeping water in the system to provide flexibility for achieving ecosystem goals.

      Dissolved organic matter within oil and gas associated wastewaters from U.S. unconventional petroleum plays: Comparisons and consequences for disposal and reuse

      Released June 08, 2022 06:53 EST

      2022, Science of the Total Environment (838)

      Bonnie McDevitt, Aaron M. Jubb, Matthew S. Varonka, Madalyn S. Blondes, Mark A Engle, Tanya J. Gallegos, Jenna L. Shelton

      Wastewater generated during petroleum extraction (produced water) may contain high concentrations of dissolved organics due to their intimate association with organic-rich source rocks, expelled petroleum, and organic additives to fluids used for hydraulic fracturing of unconventional (e.g., shale) reservoirs. Dissolved organic matter (DOM) within produced water represents a challenge for treatment prior to beneficial reuse. High salinities characteristic of produced water, often 10× greater than seawater, coupled to the complex DOM ensemble create analytical obstacles with typical methods. Excitation-emission matrix spectroscopy (EEMS) can rapidly characterize the fluorescent component of DOM with little impact from matrix effects. We applied EEMS to evaluate DOM composition in 18 produced water samples from six North American unconventional petroleum plays. Represented reservoirs include the Eagle Ford Shale (Gulf Coast Basin), Wolfcamp/Cline Shales (Permian Basin), Marcellus Shale and Utica/Point Pleasant (Appalachian Basin), Niobrara Chalk (Denver-Julesburg Basin), and the Bakken Formation (Williston Basin). Results indicate that the relative chromophoric DOM composition in unconventional produced water may distinguish different lithologies, thermal maturity of resource types (e.g., heavy oil vs. dry gas), and fracturing fluid compositions, but is generally insensitive to salinity and DOM concentration. These results are discussed with perspective toward DOM influence on geochemical processes and the potential for targeted organic compound treatment for the reuse of produced water.


      Assessment of mercury in sediments and waters of Grubers Grove Bay, Wisconsin

      Released June 07, 2022 15:08 EST

      2022, Open-File Report 2022-1051

      Evan J. Routhier, Sarah E. Janssen, Michael T. Tate, Jacob M. Ogorek, John F. DeWild, David P. Krabbenhoft

      Mercury is a global contaminant that can be detrimental to wildlife and human health. Anthropogenic emissions and point sources are primarily responsible for elevated mercury concentrations in sediments and waters. Mercury can physically move and chemically transform in the environment, resulting in biomagnification of mercury, in the form of methylmercury, in the food web and causing elevated mercury concentrations in upper trophic levels. The ability to measure total mercury concentrations in the environment has existed for several decades and makes it possible to detect hotspots that might exist because of ongoing or previous anthropogenic activity. However, recent (within the past 15 years) developments in mass spectrometry have made it possible to complete low level stable isotope analysis allowing for the determination of mercury sources—natural and anthropogenic—in the environment through “fingerprinting.” Grubers Grove Bay in Lake Wisconsin, the focus area of this study, was determined to have elevated mercury levels even after multiple remediation efforts, resulting in its listing on the Federal list of impaired waters pursuant to the Clean Water Act. Adjacent to the bay is the former Badger Army Ammunition Plant, which manufactured ammunition for the U.S. Army during the early and middle 20th century, after which it was put on standby before being fully decommissioned. This study assesses mercury concentrations in the sediments and suspended particulate matter of Grubers Grove Bay, Wiegands Bay, and upstream sites, and in adjacent soils on the former Badger Army Ammunition Plant site. This study confirmed that mercury contamination exists in the sediments of Grubers Grove Bay even after dredging attempts by the U.S. Army. Additionally, using isotope ratios and a two-endmember mixing model, it was determined that soil from within Badger Army Ammunition Plant’s former site contributed a substantial amount of mercury to the bay. This result was supported by an observed gradient of high to low mercury concentrations from the innermost (nearest Badger Army Ammunition Plant) to the outermost (farthest from Badger Army Ammunition Plant) part of the bay.

      Addressing stakeholder science needs for integrated drought science in the Colorado River Basin

      Released June 07, 2022 13:50 EST

      2022, Fact Sheet 2022-3010

      Anne C. Tillery, Sally F. House, Rebecca J. Frus, Sharon L. Qi, Daniel K. Jones, William J. Andrews

      Stakeholders need scientific data, analysis, and predictions of how drought the will impact the Colorado River Basin in a format that is continuously updated, intuitive, and easily accessible. The Colorado River Basin Actionable and Strategic Integrated Science and Technology Pilot Project was formed to demonstrate the effectiveness of addressing complex problems through stakeholder involvement and use of 21st century technology to deliver integrated science. By identifying stakeholders and their science needs, the project team is better able to prioritize integrated science and design science delivery systems to support better adaptation and management measures for the long-term drought occurring in this basin. The project team is conducting outreach and coordination with stakeholders to meet the current and future science and technology needs in the basin and fulfill the USGS vision of integrated drought science throughout the Basin. As the USGS works to streamline the approach for sharing integrated drought science in the Colorado River Basin, the project is looking for input, involvement, and collaboration to ensure the science provided works for stakeholders.

      The effects of management practices on grassland birds—Burrowing Owl (Athene cunicularia hypugaea)

      Released June 07, 2022 12:13 EST

      2022, Professional Paper 1842-P

      Jill A. Shaffer, Lawrence D. Igl, Douglas H. Johnson, Marriah L. Sondreal, Christopher M. Goldade, Paul A. Rabie, Jason P. Thiele, Betty R. Euliss

      Keys to Burrowing Owl (Athene cunicularia hypugaea) management include providing areas of short, sparse vegetation and maintaining populations of prey species and of burrowing mammals to ensure availability of burrows as nest sites. In particular, the conservation of black-tailed prairie dog (Cynomys ludovicianus) and Richardson’s ground squirrel (Urocitellus richardsonii) colonies is vital to the preservation of Burrowing Owls on the Great Plains. Burrowing Owls have been reported to use habitats with less than 31 centimeters (cm) average vegetation height, 5–12 cm visual obstruction reading, 12–36 percent grass cover, 29–45 percent forb cover, 1–11 percent shrub cover, 11–58 percent bare ground, and 6–27 percent litter cover.

      Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes

      Released June 07, 2022 09:28 EST

      2022, Wetlands (42)

      Jena A. Moon, Laura Feher, Tiffany C. Lane, William Vervaeke, Michael Osland, Douglas M. Head, Bogdan Chivoiu, David R. Stewart, Darren Johnson, James Grace, Kristine L. Metzger, Nicole M. Rankin

      Accelerated sea-level rise and intensifying hurricanes highlight the need to better understand surface elevation change in coastal wetlands. We used the surface elevation table-marker horizon approach to measure surface elevation change in 14 coastal marshes along the northwestern Gulf of Mexico, within five National Wildlife Refuges in Texas (USA). During the 2014–2019 study period, the mean rate of surface elevation change was 1.96 ± 0.87 mm yr−1 (range: -1.57 to 8.37 mm yr−1). Vertical accretion rates varied due to landscape proximity relative to sediment inputs from Hurricane Harvey. At most sites, vertical accretion offset subsurface losses due to shallow subsidence. However, net elevation gains were often lower than recent relative sea-level rise rates, and much lower than rates expected under future sea-level rise. Because these marshes are not keeping pace with recent sea-level rise, it is unlikely that they will be able to adjust to future accelerations. Climate change threatens these Texas coastal wetlands and the ecological and economic services they provide. By characterizing the status and prospective loss of coastal marshes, our study reinforces the value of identifying local and landscape-level adaptation mechanisms that can enhance the ability of coastal marshes to adapt to threats posed by climate change.

      Decadal-scale phenology and seasonal climate drivers of migratory baleen whales in a rapidly warming marine ecosystem

      Released June 07, 2022 09:04 EST

      2022, Global Change Biology

      Dan Pendleton, Morgan Tingley, Laura Ganley, Kevin Friedland, Charlie Mayo, Moria Brown, Brigid McKenna, Adrian Jordaan, Michelle Staudinger

      Species' response to rapid climate change can be measured through shifts in timing of recurring biological events, known as phenology. The Gulf of Maine is one of the most rapidly warming regions of the ocean, and thus an ideal system to study phenological and biological responses to climate change. A better understanding of climate-induced changes in phenology is needed to effectively and adaptively manage human-wildlife conflicts. Using data from a 20+ year marine mammal observation program, we tested the hypothesis that the phenology of large whale habitat use in Cape Cod Bay has changed and is related to regional-scale shifts in the thermal onset of spring. We used a multi-season occupancy model to measure phenological shifts and evaluate trends in the date of peak habitat use for North Atlantic right (Eubalaena glacialis), humpback (Megaptera novaeangliae), and fin (Balaenoptera physalus) whales. The date of peak habitat use shifted by +18.1 days (0.90 days/year) for right whales and +19.1 days (0.96 days/year) for humpback whales. We then evaluated interannual variability in peak habitat use relative to thermal spring transition dates (STD), and hypothesized that right whales, as planktivorous specialist feeders, would exhibit a stronger response to thermal phenology than fin and humpback whales, which are more generalist piscivorous feeders. There was a significant negative effect of western region STD on right whale habitat use, and a significant positive effect of eastern region STD on fin whale habitat use indicating differential responses to spatial seasonal conditions. Protections for threatened and endangered whales have been designed to align with expected phenology of habitat use. Our results show that whales are becoming mismatched with static seasonal management measures through shifts in their timing of habitat use, and they suggest that effective management strategies may need to alter protections as species adapt to climate change.

      The Pliocene-to-present course of the Tennessee River

      Released June 07, 2022 07:24 EST

      2022, Journal of Geology

      William Elijah Odom, Darryl E. Granger

      The Tennessee River, a primary drainage of the southern Appalachians and significant sediment source for the Gulf of Mexico, is generally considered to be the product of captures that rerouted the river from a more direct gulfward course. Sedimentary and genetic evidence indicates that a paleo-Tennessee flowed into the Mobile Basin through the late Miocene, although alternate models propose other redirections of the river. We constrain the river course’s age by dating terraces near Pickwick, Tennessee, with cosmogenic 26Al/10Be isochron burial dating. We find that the river’s present path dates to at least the early Pliocene.

      Rub tree use and selection by American black bears and grizzly bears in northern Yellowstone National Park

      Released June 07, 2022 06:45 EST

      2022, Ursus (2022) 1-12

      Nathaniel R. Bowersock, H. Okada, Andrea R. Litt, Kerry A. Gunther, Frank T. van Manen

      Several of the world's bear species exhibit tree-rubbing behavior, which is thought to be a form of scent-marking communication. Many aspects of this behavior remain unexplored, including differences in rub tree selection between sympatric bear species. We compiled rub tree data collected on Yellowstone National Park's Northern Range (USA) and compared rub tree selection of sympatric American black bears (Ursus americanus) and grizzly bears (U. arctos) at local and landscape scales. During 2017 and 2018, we identified 217 rub trees and detected black bears at 117 rub trees and grizzly bears at 18 rub trees, based on genetic analysis of collected hair samples. Rub trees generally were located in areas with gentle slopes and close to existing animal trails. Trees selected by black bears were typically in forested areas, whereas trees selected by grizzly bears were in forested and more open areas. Use of rub trees varied seasonally and between sexes for black bears, but seasonal data were inconclusive for grizzly bears. Black bears showed preferences for certain tree species for rubbing, but we did not find evidence that rub tree selection by grizzly bears differed among tree species. Both bear species selected trees that lacked branches on the lower portions of tree trunks and the maximum rub height was consistent with the body length of the bear species that used the tree. Although the sample size for grizzly bears was small, identifying the species and sex of bears based on genetic analysis enhanced interpretation of rub tree use and selection by bears. Scent-marking by black bears and grizzly bears on similar rub objects in well-traversed areas likely serves to enhance communication within and between the 2 species.

      Repeated genetic targets of natural selection underlying adaptation of euryhaline fishes to changing salinity

      Released June 06, 2022 18:31 EST

      2022, Integrative and Comparative Biology

      Jonathan P Velotta, Stephen D. McCormick, Andrew Whitehead, Catherine S Durso, Eric T. Schultz

      Ecological transitions across salinity boundaries have led to some of the most important diversification events in the animal kingdom, especially among fishes. Adaptations accompanying such transitions include changes in morphology, diet, whole-organism performance, and osmoregulatory function, which may be particularly prominent since divergent salinity regimes make opposing demands on systems that maintain ion and water balance. Research in the last decade has focused on the genetic targets underlying such adaptations, most notably by comparing populations of species that are distributed across salinity boundaries. Here, we synthesize research on the targets of natural selection using whole-genome approaches, with a particular emphasis on the osmoregulatory system. Given the complex, integrated and polygenic nature of this system, we expected that signatures of natural selection would span numerous genes across functional levels of osmoregulation, especially salinity sensing, hormonal control, and cellular ion exchange mechanisms. We find support for this prediction: genes coding for V-type, Ca2+, and Na+/K+-ATPases, which are key cellular ion exchange enzymes, are especially common targets of selection in species from six orders of fishes. This indicates that while polygenic selection contributes to adaptation across salinity boundaries, changes in ATPase enzymes may be of particular importance in supporting such transitions.

      Tracking heat in the Willamette River system, Oregon

      Released June 06, 2022 14:10 EST

      2022, Scientific Investigations Report 2022-5006

      Stewart A. Rounds, Laurel E. Stratton Garvin

      The Willamette River Basin in northwestern Oregon is home to several cold-water fish species whose habitat has been altered by the Willamette Valley Project, a system of 13 dams and reservoirs operated by the U.S. Army Corps of Engineers. Water-resource managers use a variety of flow- and temperature-management strategies to ameliorate the effects of upstream Willamette Valley Project dams on the habitat and viability of these anadromous and native fish. In this study, new capabilities were added to the CE-QUAL-W2 two-dimensional flow and water-quality model to inform those flow- and temperature-management strategies by tracking the quantities and ages of water and heat from individual upstream sources to downstream locations in the Willamette River system. Specifically, the fraction of water and heat attributable to upstream dam releases or other water inputs, and the fraction of heat sourced from environmental heat fluxes across the water and sediment surfaces, were tracked and quantified in the river at all locations and times simulated by the model. Applying the updated CE-QUAL-W2 models to the Willamette River system for the months of March through October in the years 2011 (cool and wet), 2015 (hot and dry), and 2016 (warm and somewhat dry) demonstrated that the influence of upstream dam releases on downstream water temperature diminished within a few days as water moved downstream. At sites that are roughly two or more days of travel from upstream dams (Albany and downstream), the July–August fraction of riverine heat content that could be tracked back to upstream dam releases typically diminished to less than 20 percent, despite the fact that roughly 50 percent of July–August streamflow could be attributed to upstream dam releases at the same sites. In contrast, the fraction of riverine heat content that could be attributed to environmental energy fluxes continued to increase with downstream distance, from about 59 to 67 percent at Albany during July–August to 62 to 73 percent at Keizer and 68 to 79 percent at Newberg.

      At locations sufficiently far downstream, upstream dam releases affect water temperature mainly through a decrease in travel time (less time for environmental heat fluxes to warm the river during summer) and an increase in thermal mass (more water to dilute and buffer incoming heat fluxes) rather than through the simple transport of heat content (water temperature) released from the dams. This concept was explored not only for the baseline conditions that occurred in March–October of 2011, 2015, and 2016, but also for a hypothetical high-flow release during August 2016 and an actual high-flow release during August 2017. In these high-flow releases, an extra 2,500 cubic feet per second (roughly) was released from Dexter Dam on the Middle Fork Willamette River, and downstream effects were measured (2017, actual) and simulated (2016, hypothetical). Results of the simulations were consistent with insights gained from the baseline conditions, such that temperature changes caused by flow augmentation were substantial in upstream reaches (measured cooling of about 1.5 °C near Harrisburg [43 miles downstream] and Albany [84 miles downstream] in 2017, and cooling of about 0.5 °C near Albany in 2016) and diminished farther downstream, but still measurable (more than a few tenths of a degree Celsius) even at Newberg, which is about 154 miles downstream. The direct downstream effects of dam releases on the river heat content attributable to those releases were increased by the hypothetical flow augmentation, with increases of 20 percent at Harrisburg and 12 percent at Keizer. Even with a decreased influence of environmental energy fluxes on river heat content, however, the fraction of heat content attributable to such fluxes was still more than 50 percent at and downstream of Albany and more than 70 percent at Newberg, where the river temperature was less affected by upstream dam-release temperatures and instead was affected primarily by a decreased travel time and increased thermal mass.

      The thermal landscape of the Willamette River—Patterns and controls on stream temperature and implications for flow management and cold-water salmonids

      Released June 06, 2022 13:31 EST

      2022, Scientific Investigations Report 2022-5035

      Laurel E. Stratton Garvin, Stewart A. Rounds

      Water temperature is a primary control on the health, diversity, abundance, and distribution of aquatic species, but thermal degradation resulting from anthropogenic influences on rivers is a challenge to threatened species worldwide. In the Willamette River Basin, northwestern Oregon, spring-run Chinook salmon (Oncorhynchus tshawytscha) and winter-run steelhead (O. mykiss) are formerly abundant cold-water-adapted species that are now protected under the Endangered Species Act. Among the challenges to the health of cold-water salmonids in the Willamette River Basin, disruptions in the seasonal patterns of stream temperature imposed by 13 large, multipurpose dams on tributaries to the Willamette River, as well as temperatures routinely in excess of regulatory limits in the Willamette River Basin, are contributing factors. To better understand controls on stream temperature, the sensitivity of stream temperature to flow augmentation as a management tool for suppressing high temperatures, and the implications for threatened salmonids, this study used a two-dimensional hydrodynamic and water-quality model (CE-QUAL-W2) to investigate spatial and temporal patterns of stream temperature in the Willamette River Basin. This study focused on the upper 160.4 river miles of the Willamette River from the confluence of the Middle Fork and Coast Fork Willamette Rivers (river mile 187.2) to Willamette Falls (river mile 26.8), three representative climate years (2011, a cool and wet year; 2015, an extremely hot and dry year; and 2016, a moderately hot and dry year), and a series of flow-augmentation scenarios. Model results show that the Willamette River upstream from Willamette Falls is divisible into four characteristic “thermal reaches” with similar thermal patterns, depending on tributary input, warming rate, and the timing of thermal response. In general, the Willamette River warms downstream during spring and summer, but patterns are complex, influenced by tributary inflows, and seasonally variable. Except in cool wet years (as illustrated by 2011), modeling suggests that adversely warm conditions for spring-run Chinook salmon are extensive from June or July through August. The thermal influence of flow augmentation from dam storage on four tributaries with U.S. Army Corps of Engineers dams varies spatially along the Willamette River, seasonally, and in magnitude, depending on a range of factors like distance from the Willamette River, the temperature of dam outflow, and the thermal template of tributary reaches controlling stream temperature adjustment to environmental heat fluxes. Modeling suggests that targeted flow management (via augmentation from dam storage) can reduce the extent and duration of thermally stressful conditions for Chinook salmon for short periods, but modeling suggests that flow augmentation is limited in its ability to fundamentally alter the “thermal landscape” (the entire range of temperature variation in a river system over space and time) of the Willamette River. While this research provides general insights into the thermal landscape of the Willamette River and its sensitivity to flow management, additional investigation into the thermal landscape of tributaries downstream from U.S. Army Corps of Engineers dams, as well as the thermal management of reservoirs, storage availability, and dam outflows, would be necessary to target specific management actions for supporting specified rearing or migration conditions for spring-run Chinook salmon and other cold-water-adapted species in the Willamette River Basin.

      Assessment of habitat availability for juvenile Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) in the Willamette River, Oregon

      Released June 06, 2022 12:46 EST

      2022, Scientific Investigations Report 2022-5034

      James S. White, James T. Peterson, Laurel E. Stratton Garvin, Tobias J. Kock, J. Rose Wallick

      The Willamette River, Oregon, is home to two salmonid species listed as threatened under the Endangered Species Act, Upper WIllamette River spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River winter steelhead (O. mykiss). Streamflow in the Willamette River is regulated by upstream dams, 13 of which are operated by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Valley Project. In 2008, these dams were determined to have a deleterious effect on Endangered Species Act-listed salmonids, resulting in USACE taking actions to mitigate those effects. Mitigation actions included setting seasonal streamflow targets at various locations along the river to improve survival and migration of juvenile salmonids. Although these targets were established with the best available information at the time, recent data and models have advanced understanding of Willamette River bathymetric, hydraulic, and thermal conditions, allowing for a more robust analysis of the effect of streamflow on downstream habitat. This study integrates those recent advances to build high-resolution models of usable habitat for juvenile Chinook salmon and steelhead to assess variation in spatial and seasonal patterns of habitat availability. Specifically, this study develops detailed maps of habitat availability for juvenile Chinook salmon and steelhead for two size classes (fry and pre-smolt). Habitat availability is modeled in a three-step process whereby (1) two-dimensional hydraulic models are paired with literature-supplied data on habitat preferences to create spatially explicit maps of rearing habitats for a wide range of streamflows; (2) reach-specific relations between streamflow and habitat area are developed and paired with streamgage records to create habitat time series for 2011, 2015, and 2016, which reflect “cool and wet,” “hot and dry,” and “warm but average precipitation” conditions, respectively; (3) temperature models are coupled with literature-based thermal thresholds to determine time periods and locations along the river corridor when rearing habitat has optimal, harmful, or lethal temperature conditions; (4) finally, habitat availability is summarized at several spatial scales to characterize longitudinal and seasonal patterns.

      Findings show that modeled area of rearing habitat for Chinook salmon and steelhead responds non-uniformly to streamflow, where habitat in some reaches of the Willamette River consistently increase with additional streamflow, while in other reaches, habitat area decreases when streamflows increase from low to moderate flows. Modeled differences in flow-habitat relations are primarily explained by local geomorphology in each reach and resulting hydraulic conditions that arise with different streamflows. These are most pronounced when comparing laterally active, multi-channel reaches upstream from Corvallis with downstream reaches that are laterally stable with single-channel planforms. The reaches upstream from Corvallis generally have more habitat available per unit stream distance than downstream reaches, but all reaches display greatest amounts of habitat at the highest streamflows. Finally, results show that warm water temperature in summer greatly decreases the utility of habitat available to the focal species, particularly downstream from Corvallis. Together, these findings serve to inform flow management by characterizing spatial and seasonal patterns of habitat availability for juvenile spring Chinook salmon and winter steelhead and provide a quantitative assessment of the effects of streamflow on rearing habitat.

      Updates to models of streamflow and water temperature for 2011, 2015, and 2016 in rivers of the Willamette River Basin, Oregon

      Released June 06, 2022 12:07 EST

      2022, Open-File Report 2022-1017

      Laurel E. Stratton Garvin, Stewart A. Rounds, Norman L. Buccola

      Mechanistic river models capable of simulating hydrodynamics and stream temperature are valuable tools for investigating thermal conditions and their relation to streamflow in river basins where upstream water storage and management decisions have an important influence on river reaches with threatened fish populations. In the Willamette River Basin in northwestern Oregon, a two-dimensional, hydrodynamic water-quality model (CEQUALW2) has been used to investigate the downstream effects of dam operations and other anthropogenic influences on stream temperature. By simulating the managed releases of water and various temperatures from the large Willamette Valley Project dams upstream of the modeling domain, these models can be used to investigate riverine temperature conditions and their relation to streamflow to determine where and when conditions are most challenging for threatened fish populations and how dam operations and flow management can affect and optimize thermal conditions in the river.

      The original models were initially developed to simulate conditions in spring–autumn of 2001 and 2002. This report documents (1) the upgrade of the river models to CE‑QUAL‑W2 version 4.2 and (2) the update of those models to simulate conditions that occurred from March through October of 2011, 2015, and 2016. These years were selected to represent a range of climatic and hydrologic conditions in the Willamette River Basin, including a “cool, wet” year (2011), a “hot, dry” year (2015), and a “normal” year (2016). Six submodels comprise the modeling system updated in this report; each submodel can be run independently or run with the others as a system. These models include the Coast Fork and Middle Fork Willamette River submodel, which includes the Coast Fork and Middle Fork Willamette Rivers, the Row River, and Fall Creek; the McKenzie River submodel, which includes the South Fork McKenzie River downstream of Cougar Dam and the McKenzie River from its confluence with the South Fork McKenzie River to its mouth; the South Santiam River submodel, which comprises the South Santiam River from Foster Dam to the Santiam River; the North Santiam and Santiam River submodel, which includes the Santiam River and the North Santiam River downstream of Big Cliff Dam; the Upper Willamette River submodel, which includes the Willamette River from Eugene to Salem; and the Middle Willamette River submodel, which includes the Willamette River from Salem to Willamette Falls near Oregon City.

      The models included in this report were originally developed, calibrated, and documented by other researchers. As part of the model updates described here, some model parameters were adjusted to improve stability and decrease runtime. Boundary conditions including meteorological, hydrologic, and thermal parameters were developed and updated for model years 2011, 2015, and 2016. In many cases, the data sources used to drive the 2001 and 2002 models were no longer available, which required the use of new data sources, the determination of a proxy record, or the development of appropriate estimation techniques. Goodness-of-fit statistics for the updated models show a good model fit, with the models simulating subdaily water temperatures at most comparable locations with a mean absolute error of generally less than 1 °C and often nearing 0.5 °C, depending on the individual submodel, and a reasonably low bias. The subdaily mean error for the South Santiam River submodel produced the highest bias of any of the submodels. Goodness-of-fit statistics indicate that the results may be biased cool (ranging from -0.43 °C in 2016 to -0.80 °C in 2011 for subdaily results), but the only water temperature data available for comparison on the South Santiam River is itself estimated, and those estimates are known to be too high in summer. Depending on future modeling needs, that submodel may warrant further refinement, along with additional data collection to properly define and minimize any model bias.

      Geologic map of the Stibnite mining area, Valley County, Idaho

      Released June 06, 2022 10:30 EST

      2022, Technical Report T-22-03

      Niki E. Wintzer

      The Stibnite mining area, as used herein, is bounded by the map extent that includes the Yellow Pine, West End, and Hangar Flats ore bodies. Other ore bodies are nearby, but the purpose of this map is to offer a detailed (1:8,000 scale) geologic map with new cross sections in the immediate area of Stibnite, Idaho. This geologic map is very similar to the Stibnite quadrangle map (Stewart and others, 2016) particularly the units and structure descriptions, because of the overlap of map extent. The new work by the author includes: (1) the topographic lines generated from the LiDAR base (courtesy of Midas Gold Corporation); (2) additional structural measurements; (3) revision of geologic unit contact placements particular around West End and Stibnite pits among other locations; and (4) seven new cross sections. New structural measurements from field work account for 20 percent of measurements shown with the remaining from Midas Gold Corp., Smitherman (1985), and the Stibnite quadrangle map (Stewart and others, 2016). Locations of many shallow features in the cross sections are controlled by core logs of 48 drillholes provided by Midas Gold Corp. The logs include dike placement, dike to plutonic bodies relationships, metasedimentary body localities, and dips of stratigraphic units. The law of sines was used to calculate dip of contacts between metasedimentary units for each cross section. Other features at depth in the cross sections are schematic based on nearby surface features and overall geologic interpretation.

      The map area contains metamorphosed sediments of Neoproterozoic and Paleozoic age within the Stibnite roof pendant. This rock package is open to tightly folded and reached lower amphibolite facies metamorphism during the Cretaceous Period. Most of the metasedimentary rocks are nearly vertical to overturned and young to the southwest, except on the southwestern flank of the Garnet Creek syncline. Pulses of the Idaho batholith granitoids intruded the metasedimentary units found in the Stibnite roof pendant. Faulting with apparent reverse, normal, and/or strike-slip offset are all present within the map area. Mineralization is largely fault controlled with some stratigraphic control. Volumetrically minor dikes, sills, and small intrusions are of Eocene age, and these intrusions are mostly depicted on the cross sections. Quaternary surficial deposits occur in stream beds and glaciated areas.

      Field work was conducted during the summers of 2013, 2015, and 2016. For consistency with recent research, most of the Stibnite quadrangle geologic map units (Stewart and others, 2016) are used for this geologic map. Intrusive units Kqd and Tba are new. The additional geologic mapping by the authors and compilation of detailed geologic maps from Midas Gold Corp. enhanced resolution. Cross sections incorporated drill core data including rock type, unit thickness, and oriented structural measurements offering detailed subsurface control. Data access was courtesy of Midas Gold Corp. Reed S. Lewis, Russell V. Di Fiori, and Claudio Berti provided constructive reviews that significantly improved this maps and cross sections. Previous studies that focus on mineralization include Schrader and Ross (1925), Currier (1935), White (1940), Cooper (1951), Cookro and others (1988), and more recently Gillerman and others (2019). Digital map files are available online (Wintzer, 2022).

      Managing macropods without poisoning ecosystems

      Released June 06, 2022 08:45 EST

      2022, Ecological Management & Restoration

      Jordan O Hampton, James M. Pay, Todd E. Katzner, Jon M Arnemo, Mark A Pokras, Eric Buenz, Niels Kanstrup, Vernon G Thomas, Marcela Uhart, Sergio A Lambertucci, Oliver Krone, Navinder J Singh, Vinny Naidoo, Mayumi Ishizuka, Keisuke Saito, Björn Helander, Rhys E. Green

      A recent review of the management of hyperabundant macropods in Australia proposed that expanded professional shooting is likely to lead to better biodiversity and animal welfare outcomes. While the tenets of this general argument are sound, it overlooks one important issue for biodiversity and animal health and welfare: reliance on toxic lead-based ammunition. Lead poisoning poses a major threat to Australia's wildlife scavengers. Current proposals to expand professional macropod shooting would see tonnes of an extremely toxic and persistent heavy metal continue to be introduced into Australian environments. This contrasts with trends in many other countries, where lead ammunition is, through legislation or voluntary programs, being phased out. Fortunately, there are alternatives to lead ammunition that could be investigated and adopted for improved macropod management. A transition to lead-free ammunition would allow the broad environmental and animal welfare goals desired from macropod management to be pursued without secondarily and unintentionally poisoning scavengers. Through this article, we hope to increase awareness of this issue and encourage discussion of this potential change.

      Sample size estimation for savanna monitoring protocol development

      Released June 06, 2022 07:14 EST

      2022, Open-File Report 2022-1053

      Deborah A. Buhl

      When designing data collection protocols for a new research project, it is important to have a large enough sample size to detect a desired effect, but not so large to be wasting time collecting more data than needed. Power analysis methods can be used to estimate this sample size. In this report, power analyses used to estimate sample sizes needed for a savanna monitoring study, for which the U.S. Fish and Wildlife Service are developing protocols, are described. Power analyses were run to estimate the sample sizes needed to detect a specified difference (that is, effect size) between means from two savanna areas or between yearly means for a savanna area. Sample sizes were estimated for nine different vegetation metrics that will be measured in savanna areas. Analyses were run for each metric using a range of means and variances, effect sizes, and correlation among repeated measures. Sample size estimates varied among vegetation metrics. Within each vegetation metric, estimated sample sizes varied with means, variances, effect size, and correlation. Many of the sample size estimates were too large to be feasible when sampling; therefore, the tables of estimated sample sizes may be first used as a guide to determine an adequate and feasible sample size that will detect differences in some vegetation metrics. Then, using this sample size, the tables can be used to estimate the effect sizes for each vegetation metric that may be detectable for a given mean, variance, and correlation.

      Regional walrus abundance estimate in the United States Chukchi Sea in autumn

      Released June 06, 2022 06:57 EST

      2022, Journal of Wildlife Management

      Anthony S. Fischbach, Rebecca L. Taylor, Chadwick V. Jay

      Human activities (e.g., shipping, tourism, oil, gas development) have increased in the Chukchi Sea because of declining sea ice. The declining sea ice itself and these activities may affect Pacific walrus (Odobenus rosmarus divergens) abundance; however, previous walrus abundance estimates have been notably imprecise. When sea ice is absent from the eastern Chukchi Sea, walruses in waters of the United States usually rest together onshore at a single Alaska coastal haulout, where they can be surveyed more easily than when they rest on dispersed offshore ice floes. We estimated the number of walruses on land (herd size) at this haulout from 13 unoccupied aircraft system (UAS) surveys flown within a 10-day period in each of 2018 and 2019. We estimated population size of walruses using the haulout over the course of the surveys by combining herd size data with data from satellite-linked transmitters that indicated whether tagged walruses were in or out of water during each survey. Our estimates of the population size of walruses using the haulout during each year's survey period were similar to each other and more precise than historical walrus abundance estimates: posterior means (95% credibility intervals) were 166,000 (133,000–201,000) for 2018 and 189,000 (135,000–251,000) for 2019. Auxiliary observations support using these estimates to represent the size of the population using the eastern Chukchi Sea in autumn during the surveyed years. Our study site was the only substantial Chukchi Sea coastal haulout in the United States during the survey periods and study-specific tracking data (consistent with known distribution and movement patterns) indicated tagged walruses remained in eastern Chukchi waters during the survey periods. In addition, the imagery, telemetry, and analytical methods developed for this study advance the prospect for precise range-wide walrus population size estimates.

      Damage assessment for the 2018 lower East Rift Zone lava flows of Kīlauea volcano, Hawaiʻi

      Released June 06, 2022 06:50 EST

      2022, Bulletin of Volcanology (84)

      Elinor S. Meredith, Susanna F. Jenkins, Josh L. Hayes, Natalia Irma Deligne, David Lallemant, Matthew R. Patrick, Christina A. Neal

      Cataloguing damage and its correlation with hazard intensity is one of the key components needed to robustly assess future risk and plan for mitigation as it provides important empirical data. Damage assessments following volcanic eruptions have been conducted for buildings and other structures following hazards such as tephra fall, pyroclastic density currents, and lahars. However, there are relatively limited quantitative descriptions of the damage caused by lava flows, despite the number of communities that have been devastated by lava flows in recent decades (e.g., Cumbre Vieja, La Palma, 2021; Nyiragongo, Democratic Republic of Congo, 2002 and 2021; Fogo, Cape Verde, 2014–2015). The 2018 lower East Rift Zone (LERZ) lava flows of Kīlauea volcano, Hawaiʻi, inundated 32.4 km2 of land in the Puna District, including residential properties, infrastructure, and farmland. During and after the eruption, US Geological Survey scientists and collaborators took over 8000 aerial and ground photographs and videos of the eruption processes, deposits, and impacts. This reconnaissance created one of the largest available impact datasets documenting an effusive eruption and provided a unique opportunity to conduct a comprehensive damage assessment. Drawing on this georeferenced dataset, satellite imagery, and 2019 ground-based damage surveys, we assessed the pre-event typology and post-event condition of structures within and adjacent to the area inundated by lava flows during the 2018 LERZ eruption. We created a database of damage: each structure was assigned a newly developed damage state and data quality category value. We assessed 3165 structures within the Puna District and classified 1839 structures (58%) as destroyed, 90 structures (3%) as damaged, and 1236 (39%) as unaffected. We observed a range of damage states, affected by the structural typology and hazard characteristics. Our study reveals that structures may be damaged or destroyed beyond the lava flow margin, due to thermal effects from the lava flow, fire spread, or from exposure to a range of hazards associated with fissure eruptions, such as steam, volcanic gases, or tephra fall. This study provides a major contribution to the currently limited evidence base required to forecast future lava flow impacts and assess risk.

      Maize yield forecasts for Sub-Saharan Africa using Earth Observation data and machine learning

      Released June 06, 2022 06:44 EST

      2022, Global Food Security (33)

      Donghoon Lee, Frank Davenport, Shraddhanand Shukla, Gregory Husak, W. Chris Funk, Laura Harrison, Amy McNally, Michael Budde, James Rowland, James Verdin

      Food insecurity continues to grow in Sub-Saharan Africa (SSA). In 2019, chronically malnourished people numbered nearly 240 million, or 20% of the population in SSA. Globally, numerous efforts have been made to anticipate potential droughts, crop conditions, and food shortages in order to improve early warning and risk management for food insecurity. To support this goal, we develop an Earth Observation (EO) and machine-learning-based operational, subnational maize yield forecast system and evaluate its out-of-sample forecast skills during the growing seasons for Kenya, Somalia, Malawi, and Burkina Faso. In general, forecast skills improve substantially during the vegetative growth period (VP) and gradually during the reproductive development period (RP). Thus, mid-season assessment can provide effective early warning months before harvest. Skillful forecasts (Nash Sutcliffe Efficiency (NSE) > 0.6 and Mean Absolute Percentage Error (MAPE) < 20%) appear approximately two dekads after the VP; for example, skillful forecasts appear in May in Kenya and Somalia, January in Malawi, and July in Burkina Faso. During model development, effective EO features are also identified, such as precipitation and available water during VP, and dry days and extreme temperatures in early VP. Compared to monthly standard EO features, sub-monthly (dekadal), non-standard, and serial EO features significantly improve forecast skills by + 0.3 NSE and -10% of MAPE, demonstrating the ability to precisely and effectively capture favorable or detrimental crop development conditions. Finally, skillful forecasts and practical utility are demonstrated in the recent normal and dry years in each region. Overall, the developed yield forecasting system can provide skillful predictions during the growing season, supporting regional and international agricultural decision-making processes, including informing food-security planning and management, thereby helping to mitigate food shortages caused by unfavorable climate conditions.

      Maintenance and dissemination of avian-origin influenza A virus within the northern Atlantic Flyway of North America

      Released June 06, 2022 06:40 EST

      2022, PLoS Pathogens

      Diann Prosser, Jiani Chen, Christina Ahlstrom, Andrew B. Reeves, Rebecca L. Poulson, Jeffery D Sullivan, Daniel McAuley, Carl R. Callahan, Peter C. McGowan, Justin Bahl, David E. Stallknecht, Andrew M. Ramey

      Wild waterbirds, the natural reservoirs for avian influenza viruses, undergo migratory movements each year, connecting breeding and wintering grounds within broad corridors known as flyways. In a continental or global view, the study of virus movements within and across flyways is important to understanding virus diversity, evolution, and movement. From 2015 to 2017, we sampled waterfowl from breeding (Maine) and wintering (Maryland) areas within the Atlantic Flyway (AF) along the east coast of North America to investigate the spatio-temporal trends in persistence and spread of influenza A viruses (IAV). We isolated 109 IAVs from 1,821 cloacal / oropharyngeal samples targeting mallards (Anas platyrhynchos) and American black ducks (Anas rubripes), two species having ecological and conservation importance in the flyway that are also host reservoirs of IAV. Isolates with >99% nucleotide similarity at all gene segments were found between eight pairs of birds in the northern site across years, indicating some degree of stability among genome constellations and the possibility of environmental persistence. No movement of whole genome constellations were identified between the two parts of the flyway, however, virus gene flow between the northern and southern study locations was evident. Examination of banding records indicate direct migratory waterfowl movements between the two locations within an annual season, providing a mechanism for the inferred viral gene flow. Bayesian phylogenetic analyses provided evidence for virus dissemination from other North American wild birds to AF dabbling ducks (Anatinae), shorebirds (Charidriformes), and poultry (Galliformes). Evidence was found for virus dissemination from shorebirds to gulls (Laridae), and dabbling ducks to shorebirds and poultry. The findings from this study contribute to the understanding of IAV ecology in waterfowl within the AF.

      Streamflow reconstructions from tree rings and variability in drought and surface water supply for the Milk and St. Mary River basins

      Released June 05, 2022 06:55 EST

      2022, Quaternary Science Reviews (288)

      Justin Martin, Gregory T. Pederson

      The Milk and St. Mary Rivers are international waterways straddling the United States and Canada and traversing four Tribal Nations before draining into the Missouri and South Saskatchewan Rivers respectively. Management of water resources in the region is challenged by the complexity of stakeholder interests, the limitations of existing management infrastructure, and by a limited characterization of the long-term streamflow and hydroclimatic variability across the area. We used existing records of natural streamflow to investigate the relationships between seasonal climate variability and differences in the timing and volume of flow from the headwaters to the prairie tributaries. Then, using a network of tree-ring chronologies to reconstruct records of past streamflow, we assessed whether drought risk relates to these sub-basin specific differences and if drought events experienced during the observational period are representative of those that have occurred over the long-term. Observed climate-flow relationships suggest that outside of the mountain headwaters, where precipitation dominates the hydrograph, streamflow variability on lower reaches of the Milk River is particularly sensitive to winter temperatures. This sensitivity was reflected by severe drought conditions over the prairies during the 2000s, implying potentially large future flow reductions with warming. The streamflow reconstructions show sub-basin specific drought risks that also imply greater temperature driven drought severities across the prairie tributaries. Within the mountain and foothill sub-basins numerous past drought episodes exceed the magnitude and duration of observational period events, which implies the potential for future water supply management challenges stemming from severe, long-duration droughts coupled with the negative hydrologic effects of warmer temperatures.

        Global tellurium supply potential from electrolytic copper refining

        Released June 05, 2022 06:40 EST

        2022, Resources, Conservation & Recycling (184)

        Nedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. Hayes

        The transition towards renewable energy requires increasing quantities of nonfuel mineral commodities, including tellurium used in certain photovoltaics. While demand for tellurium may increase markedly, the potential to increase tellurium supply is not well-understood. In this analysis, we estimate the quantity of tellurium contained in anode slimes generated by electrolytic copper refining by country between 1986 and 2018, including uncertainties. For 2018, the results indicate that 1930 (1500-2700, 95% confidence interval) metric tons of tellurium were contained in anode slimes globally. This is nearly quadruple the reported tellurium production for that year. China has the greatest potential to increase tellurium supplies. However, most of the tellurium potentially recoverable by Chinese refineries appears to come from copper mined elsewhere. Further research into the business decisions associated with tellurium recovery may help translate the physical availability of tellurium into economic availability. The methodology presented here can be applied to other byproduct elements.