U.S. Geological Survey Karst Interest Group Proceedings, October 19–20, 2021
Released October 18, 2021 14:50 EST
2021, Scientific Investigations Report 2020-5019
Eve L. Kuniansky, Lawrence E. Spangler, editor(s)
Karst hydrogeologic systems represent challenging and unique conditions to scientists attempting to study groundwater flow and contaminant transport. Karst terrains are characterized by distinct and beautiful landscapes, caverns, and springs, and many of the exceptional karst areas are designated as national or state parks. The range and complexity of landforms and groundwater flow systems associated with karst terrains are enormous, perhaps more than any other type of aquifer.
The U.S. Geological Survey (USGS) Karst Interest Group (KIG), formed in 2000, is a loosely knit, grassroots organization of USGS and non-USGS scientists and researchers devoted to fostering better communication among scientists working on, or interested in, karst aquifers. The primary mission of the KIG is to encourage and support interdisciplinary collaboration and technology transfer among scientists working in karst areas. To accomplish its mission, the KIG has organized a series of workshops. To date (2021), eight KIG workshops, including the workshop documented in this report, have been held. This workshop is the first virtual workshop. The abstracts and extended abstracts provide a snapshot in time of past and current karst-related studies. The field trip guide is included in the proceedings volume even though the field trip will not occur in person.
Methods of data collection and analysis for an assessment of karst aquifer systems between Albany and Buffalo, New York
Released October 18, 2021 10:25 EST
2021, Scientific Investigations Report 2021-5094
Bradley A. Sporleder, Benjamin N. Fisher, Douglas S. Keto, William M. Kappel, James E. Reddy
The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, catalogued aquifers and closed depressions in a karst-prone area between Albany and Buffalo, New York to provide resource managers information to more efficiently manage and protect groundwater resources. The New York State Department of Environmental Conservation has been working with the agricultural industry to raise awareness of karst aquifer contamination susceptibility and how to reduce effects on surface water and groundwater resources, especially in karst areas. There is also a need to make industries, State and local regulators, planners, and the public aware of New York’s karst resources to properly protect and manage these resources and the quality of surface water and groundwater that flows through the karst aquifer.
Publicly available geospatial data were identified, collated, and analyzed for a region of karst terrain extending from Albany to Buffalo. The region was divided into 10 subareas. A series of geospatial datasets were assembled to determine the location and extent of karstic rock; bedrock geology and depth to bedrock; average water-table configuration; surficial geology; soil type, thickness, and hydraulic conductivity; land cover; and closed depressions in the land surface.
Repeated glaciation and recession across New York have left the landscape pockmarked with closed depressions, which may or may not be related to the underlying bedrock. Closed depressions in areas where carbonate or evaporite karst are present are of primary concern to this study because of the increased potential of karst aquifer contamination from focused recharge. Closed depressions present in areas not associated with karst bedrock can also be evaluated to better understand their ability to transmit surface water to the groundwater system. Information on closed depressions can be used to develop land-management plans to protect local and regional water resources.
Sediment transport in the Yankee Fork of the Salmon River near Stanley, Idaho, water years 2012–19
Released October 18, 2021 09:44 EST
2021, Scientific Investigations Report 2021-5111
Gregory M. Clark, Scott D. Ducar
Placer and dredging operations in the Yankee Fork Basin, Idaho, have left more than 5 miles of the lower Yankee Fork of the Salmon River (Yankee Fork) in a highly altered fluvial condition, resulting in poor habitat quantity and quality for native fish species. Since 2011, the Bureau of Reclamation and other stakeholders have implemented a series of restoration efforts to improve the connectivity of the river with its floodplain and to improve aquatic and terrestrial habitat in the Yankee Fork. In conjunction with these rehabilitation efforts, the U.S. Geological Survey monitored streamflow and suspended-sediment and bedload transport during water years 2012–19 at four sites in the affected lower reach of the Yankee Fork. The objectives of the monitoring were to (1) identify source areas of sediment, (2) quantify sediment transport in the lower Yankee Fork, and (3) provide a benchmark to evaluate the effects of rehabilitation efforts in the basin.
During the 8 years of sampling, the annual flow-weighted suspended-sediment concentrations (SSCs) were largest at the most downstream Clayton site, ranging from a low of 11 milligrams per liter (mg/L) in 2015 to 145 mg/L in 2017. The Clayton site also had the largest flow-weighted concentrations of suspended sand and suspended fines. At relatively low streamflow, the fine-grained fraction of the suspended sediment was the dominant component of the SSC at all sites, with an increase in the sand-size fraction as streamflow increased during snowmelt runoff. Each of the three main-stem Yankee Fork sites indicated a large amount of hysteresis in SSCs during snowmelt runoff, with concentrations on the rising limb of the hydrograph larger than concentrations on the falling limb at similar streamflow. Hysteresis was particularly evident in the fine-grained fraction of suspended sediment, indicating that sediment transport in the lower Yankee Fork is more limited by the supply of fine-grained sediment as compared to coarser-grained sediment.
A comparison of Landsat 8 Operational Land Imager and Provisional Aquatic Reflectance science product, Sentinel–2B, and WorldView–3 imagery for empirical satellite-derived bathymetry, Unalakleet, Alaska
Released October 18, 2021 09:10 EST
2021, Scientific Investigations Report 2021-5097
Sandra K. Poppenga, Jeffrey J. Danielson
Satellite-derived bathymetry (SDB) based upon an empirical band ratio method is a cost-effective means for mapping nearshore bathymetry in coastal areas vulnerable to natural hazards. This is particularly important for the low-lying coastal community of Unalakleet, Alaska, that has been negatively affected not only by flooding, storm surge, and historically strong storms but also by high erosion rates stemming from the Unalakleet River and Norton Sound. The purpose of this study was to assess the viability of different satellite imagery, including Landsat 8 (L8) Operational Land Imager, Sentinel–2B, WorldView–3, and L8 Provisional Aquatic Reflectance science product, for deriving SDB for Unalakleet, Alaska. Correlations were performed between satellite imagery band ratios and topobathymetric (topobathy) light detection and ranging (lidar) and in situ single-beam sound navigation and ranging (sonar). The satellite imagery correlations with topobathy lidar did not yield as high of a linear relation with water depths as the satellite imagery correlations with the single-beam sonar. An extinction depth, where light no longer attenuates through the water column, was not identified because of the shallow depths within the topobathy lidar and single-beam sonar datasets. Although some single-beam soundings measured at 7 meters deep, the correlations with the SDB band ratios did not yield a strong linear relation. Satellite imagery band ratio correlations with Electronic Navigational Chart soundings did not yield a strong linear relation because of older source data. Less than optimal linear regressions were most likely due to the geography of Unalakleet, Alaska, a low-lying coastal community subject to high erosion rates from surrounding waters. This study is one of the first attempts to compare different satellite imagery band ratio correlations with topobathy lidar and in situ sonar to assess the viability for nearshore SDB for coastal Unalakleet, Alaska.
Influence of permafrost type and site history on losses of permafrost carbon after thaw
Released October 16, 2021 06:29 EST
2021, Journal of Geophysical Research-Biogeosciences
Kristen L. Manies, Miriam C. Jones, Mark Waldrop, Mary-Catherine Leewis, Christopher C. Fuller, Robert S. Cornman, Kristen Hoefke
Scavengers reduce potential brucellosis transmission risk in the Greater Yellowstone Ecosystem
We quantified permafrost peat plateau and post-thaw carbon (C) stocks across a chronosequence in Interior Alaska to evaluate the amount of C lost with thaw. Macrofossil reconstructions revealed three stratigraphic layers of peat: (1) a base layer of fen/marsh peat, (2) peat from a forested peat plateau (with permafrost) and, (3) collapse-scar bog peat (at sites where permafrost thaw has occurred). Radiocarbon dating revealed that peat initiated within the last 2,500 years and that permafrost aggraded during the Little Ice Age (ca. 250 – 575 years ago) and degraded within the last several decades. The timing of permafrost thaw within each feature was not related to thaw bog size. Their rate of expansion may be more influenced by local factors, such as ground ice content and subsurface water inputs. We found C losses due to thaw over the past century were up to 46% of the C available, but the absolute amount of C lost (kg m-2) was over 50% lower than losses previously described in other Alaskan peatland chronosequences. We hypothesize that this difference stems from the process by which permafrost aggraded, with sites that formed permafrost epigenetically (significantly later than most peat accumulation) experiencing less absolute C loss with thaw than sites that formed syngenetically (simultaneously with peat accumulation). Epigenetic peat from our site had lower C:N ratios as compared to Alaskan sites that have syngenetic peat. This difference could help predict the magnitude of C loss with thaw across a range or permafrost types and histories.
Released October 14, 2021 08:04 EST
2021, Ecosphere (10)
Kimberly E Szcodronski, Paul Cross
Scavengers likely play an important role in ecosystem energy flow as well as disease transmission, but whether they facilitate or reduce disease transmission is often unknown. In the Greater Yellowstone Ecosystem, scavengers are likely to reduce the transmission and subsequent spread of brucellosis within and between livestock and elk by consuming infectious abortion materials, thereby removing the infectious agent from the landscape. We used remote cameras to monitor the time to removal of simulated abortion materials by scavengers at 264 sites from February to June in 2017 and 2018 and assessed the effects of habitat and land management on time to removal in southwest Montana. Time to removal of fetal materials decreased in grassland habitats (
Impact of spectral resolution on quantifying cyanobacteria in lakes and reservoirs: A machine-learning assessment
Released October 14, 2021 05:55 EST
2021, IEEE Transactions in Geoscience and Remote Sensing
Kiana Zolfaghari, Nima Pahlevan, Caren Binding, Daniela Gurlin, Stefan G.H. Simis, Antonio Ruiz Verdú, Lin Li, Christopher J. Crawford, Andrea VanderWoude, Reagan Errera, Arthur Zastepa, Claude R. Duguay
Cyanobacterial harmful algal blooms are an increasing threat to coastal and inland waters. These blooms can be detected using optical radiometers due to the presence of phycocyanin (PC) pigments. The spectral resolution of best-available multispectral sensors limits their ability to diagnostically detect PC in the presence of other photosynthetic pigments. To assess the role of spectral resolution in the determination of PC, a large (N = 905) database of colocated in situ radiometric spectra and PC are employed. We first examine the performance of selected widely used machine-learning (ML) models against that of benchmark algorithms for hyperspectral remote sensing reflectance ( Rrs) spectra resampled to the spectral configuration of the Hyperspectral Imager for the Coastal Ocean (HICO) with a full-width at half-maximum (FWHM) of < 6 nm. Results show that the multilayer perceptron (MLP) neural network applied to HICO spectral configurations (median errors < 65%) outperforms other ML models. This model is subsequently applied to Rrs spectra resampled to the band configuration of existing satellite instruments and of the one proposed for the next Landsat sensor. These results confirm that employing MLP models to estimate PC from hyperspectral data delivers tangible improvements compared with retrievals from multispectral data and benchmark algorithms (with median errors between ~73% and 126%) and shows promise for developing a globally applicable cyanobacteria measurement approach.
A 40-year story of river sediment at Mount St. Helens
Released October 13, 2021 14:58 EST
2021, Fact Sheet 2021-3004
Mark A. Uhrich, Kurt R. Spicer, Adam R. Mosbrucker, Dennis R. Saunders, Tami S. Christianson
The 1980 eruption of Mount St. Helens in Washington State unleashed one of the largest debris avalanches (landslide) in recorded history. The debris avalanche deposited 3.3 billion cubic yards of material into the upper North Fork Toutle River watershed and obstructed the Columbia River shipping channel downstream. From the eruption on May 18, 1980, to September 30, 2018, the Toutle River transported a total of about 405 million tons of sediment into the lower Cowlitz River—enough to bury downtown Portland, Oregon, to a depth of 300 feet. Excluding the massive sediment load from the eruption itself, from October 1, 1980, to September 30, 2018, the Toutle River transported more than 248 million tons of sediment, or an average of 6.5 million tons per year.
Increased flood risk to downstream communities is managed by a sediment retention structure, grade building structures, berms, levees, and dredging. Near-real-time monitoring of streamflow and sediment yield is important for effective management of these dynamic mitigation efforts. Since the sediment retention structure began trapping sediment in November 1987, the Toutle River has transported on average 2.8 million tons of sediment per year into the lower Cowlitz River. This is still 10 times greater than pre-eruption levels, with higher sediment transport potentially approaching 50 to 100 times greater during storms. Despite the eruption lasting only a few hours, the socioeconomic effects and mitigation measures for the region continue into the 21st century.
Water Quality in Big Cypress National Preserve and Everglades National Park - Trends and Spatial Characteristics of Selected Constituents
Released October 13, 2021 12:35 EST
2004, Water-Resources Investigations Report 2003-4249
Ronald L. Miller, Benjamin F. McPherson, Robert Sobczak, Christine Clark
Seasonal changes in water levels and flows in Big Cypress National Preserve (BICY) and Everglades National Park (EVER) affect water quality. As water levels and flows decline during the dry season, physical, geochemical and biological processes increase the breakdown of organic materials and the build-up of organic waste, nutrients, and other constituents in the remaining surface water. For example, concentrations of total phosphorus in the marsh are less than 0.01 milligram per liter (mg/L) during much of the year. Concentrations can rise briefly above this value during the dry season and occasionally exceed 0.1 mg/L under drought conditions.
Long-term changes in water levels, flows, water management, and upstream land use also affect water quality in BICY and EVER, based on analysis of available data (1959-2000). During the 1980's and early 1990's, specific conductance and concentrations of chloride increased in the Taylor Slough and Shark River Slough. Chloride concentrations more than doubled from 1960 to 1990, primarily due to greater canal transport of high dissolved solids into the sloughs. Some apparent long-term trends in sulfate and total phosphorus were likely attributable, at least in part, to high percentages of less-than and zero values and to changes in reporting levels over the period of record. High values in nutrient concentrations were evident during dry periods of the 1980's and were attributable either to increased canal inflows of nutrient-rich water, increased nutrient releases from breakdown of organic bottom sediment, or increased build-up of nutrient waste from concentrations of aquatic biota and wildlife in remaining ponds. Long-term changes in water quality over the period of record are less pronounced in the western Everglades and the Big Cypress Swamp; however, short-term seasonal and drought-related changes are evident.
Water quality varies spatially across the region because of natural variations in geology, hydrology, and vegetation and because of differences in water management and land use. Nutrient concentrations are relatively low in BICY and EVER compared with concentrations in parts of the northern Everglades that are near agricultural and urban lands. Concentrations of total phosphorus generally are higher in BICY (median values, 1991-2000, were mostly greater than 0.015 mg/L) than in EVER (median values, 1991-2000, less than 0.01 mg/L), probably because of higher phosphorus in natural sources such as shallow soils, rocks, and ground water in the Big Cypress region than in the Everglades region. Conversely, concentrations of chloride and sulfate are higher in EVER (median values in Shark River Slough, 1991-2000, mostly greater than 2 mg/L sulfate and 50 mg/L chloride) than in BICY (median values, 1991-2000, less than 1 mg/L sulfate and at most sites less than 20 mg/L chloride), probably because of the canal transport system, which conveys more water from an agricultural source into EVER than into BICY.
Trace elements and contaminants such as pesticides and other toxic organic compounds are in relatively low concentrations in BICY and EVER compared with concentrations in parts of the northern Everglades near agricultural and urban sources. Concentrations rarely exceeded aquatic life criteria in BICY and EVER. Atrazine was the only pesticide found in water that exceeded the criteria (in 2 out of 304 samples). The pesticides heptachlor expoxide, lindane, and p,p?-DDE exceeded criteria in canal bed sediments in 1, 2, and 16 percent of the samples, respectively.
Seagrass status and trends in the northern Gulf of Mexico: 1940-2002
Released October 13, 2021 12:30 EST
2007, Scientific Investigations Report 2006-5287
D. Altsman, R. DeMay
L. Handley, editor(s)
Over the past century, seagrass habitats from the bays of Texas to the gulf shores of Florida have decreased. Seagrass beds, which are highly dependent on water quality and clarity for survival, are home to a multitude of aquatic plants and animals and a source of economic activity through commercial and recreational fishing and ecotourism. The U.S. Environmental Protection Agency’s Gulf of Mexico Program (GMP) and its partners have made a commitment to restore, enhance, and protect this important ecosystem. As seagrass habitats decrease, the need for information on the causes and effects of seagrass loss, current mapping information, and education on the importance of seagrassess becomes greater. This report is the initial effort of the GMP’s research and restoration plan for seagrasses. The purpose of this report is to provide scientists, managers, and citizens with valuable baseline information on the status and trends of seagrasses in coastal waters of the Gulf of Mexico. Within the northern Gulf of Mexico region, 14 individual estuarine systems where seagrasses occur, as well as statewide summaries for Texas, Louisiana, Mississippi, Alabama, and Florida, are examined in this study. Each estuarine system is detailed in vignettes that address current and historical extent and quality of seagrasses, seagrass mapping and monitoring, causes of status change, restoration and enhancement activities, background information for the entire study area as well as the subareas for study, and the methodology employed to analyze and document the historical trends and current status of seagrasses.
The systems, moving from west to east, include the Laguna Madre, Texas Coastal Bend region, and Galveston Bay in Texas; the Chandeleur Islands in Louisiana; the Mississippi Sound; and Perdido Bay, Pensacola/Escambia Bay, Choctawhatchee Bay, St. Andrew Bay, Florida’s Big Bend region, Tampa Bay/St. Joseph Sound, Sarasota Bay, Greater Charlotte Harbor, and Florida Bay in Florida. (Mobile Bay is dealt with only in the statewide summary for Alabama.)
Interactions between surface water and ground water and effects on mercury transport in the north-central Everglades
Released October 13, 2021 12:30 EST
2002, Water-Resources Investigations Report 2002-4050
Judson W. Harvey, Steven L. Krupa, Cynthia Gefvert, Robert H. Mooney, Jungyill Choi, Susan A. King, Jefferson B. Giddings
The hydrology of the north-central Everglades was altered substantially in the past century by canal dredging, land subsidence, ground-water pumping, and levee construction. Vast areas of seasonal and perennial wetlands were converted to uses for agriculture, light industry, and suburban development. As the catchment area for the Everglades decreased, so did the sources of water from local precipitation and runoff from surrounding uplands. Partly in response to those alterations, water-resources managers compartmentalized the remaining wetlands in the north-central Everglades into large retention basins, called Water Conservation Areas (WCAs). In spite of efforts to improve how water resources are managed, the result has been frequent periods of excessive drying out or flooding of the WCAs because the managed system does not have the same water-storage capacity as the pre-drainage Everglades. Linked to the hydrological modifications are ecological changes including large-scale invasions of cattail, loss of tree islands, and diminishing bird populations in the Everglades. Complex interactions among numerous physical, chemical, and biological factors are responsible for the long-term degradation of the ecological character of the Everglades.Over the past 15 years, a new set of smaller wetland basins, called Stormwater Treatment Areas (STAs), have been designed and constructed by water-resources engineers on the former wetlands adjacent to WCAs. The purpose of STAs is to remove excess nutrients from agricultural drainage water prior to its input to WCAs. STAs tend to be about one-tenth the size of a WCA, and they are located on former wetlands on the northwestern side of WCAs on sites that were managed as farmland for much of the twentieth century in an area referred to as the Everglades Agricultural Area, or EAA. The objective of the present investigation was to quantify interactions between surface water and ground water in the Everglades Nutrient Removal Project (ENR), a prototype project for the STAs that began operation in 1994. Determining the effect of ground water on the mercury balance of the ENR treatment wetland was an important additional objective. In order to broaden the relevance of conclusions to all parts of the north-central Everglades, interactions between surface water and ground water and mercury also were investigated in Water Conservation Area 2A (WCA-2A) and, to a lesser extent, in two other WCA basins, WCA-2B and WCA-3A.An important conclusion of this study is that creation of the WCA basins, and accompanying water-resources management, have appreciably increased both recharge and discharge in the north-central Everglades compared with pre-drainage conditions. Recharge and discharge are highest near the northern and northwestern edges of the Everglades, in the relatively small basins such as ENR and the STAs that share borders with both WCA-1 and the EAA. All basins experienced greater increases in recharge relative to discharge, because of the effects that land subsidence and ground-water pumping outside the Everglades had on hydraulic gradients. The highest basin-wide estimate of recharge was measured in ENR, where recharge averaged 0.9 centimeter per day (cm/d) over a 4-year study period. For perspective, that estimate of recharge is the equivalent of 30 percent of pumped surface-water inflows and 230 percent of average daily precipitation in ENR. Ground-water discharge was 10 times smaller than recharge at ENR. The present study estimated a basin-averaged recharge for WCA-2A (0.2 cm/d) that was a factor of 4 smaller than ENR. Although preliminary, that estimate of recharge is 5 times higher than previous estimates (approximately 0.04 cm/d), probably because the newer measurements were able to quantify recharge and discharge at finer spatial and temporal scales. Recharge at WCA-2A is smaller than ENR because WCA-2A has a smaller topographic gradient (3 x 10-5 and 2 x 10-4 in WCA-2A and ENR, respective
Inventory and review of aquifer storage and recovery in southern Florida
Released October 13, 2021 12:30 EST
2002, Water-Resources Investigations Report 2002-4036
Ronald S. Reese
Aquifer storage and recovery in southern Florida has been proposed on an unprecedented scale as part of the Comprehensive Everglades Restoration Plan. Aquifer storage and recovery wells were constructed or are under construction at 27 sites in southern Florida, mostly by local municipalities or counties located in coastal areas. The Upper Floridan aquifer, the principal storage zone of interest to the restoration plan, is the aquifer being used at 22 of the sites. The aquifer is brackish to saline in southern Florida, which can greatly affect the recovery of the freshwater recharged and stored.
Well data were inventoried and compiled for all wells at most of the 27 sites. Construction and testing data were compiled into four main categories: (1) well identification, location, and construction data; (2) hydraulic test data; (3) ambient formation water-quality data; and (4) cycle testing data. Each cycle during testing or operation includes periods of recharge of freshwater, storage, and recovery that each last days or months. Cycle testing data include calculations of recovery efficiency, which is the percentage of the total amount of potable water recharged for each cycle that is recovered.
Calculated cycle test data include potable water recovery efficiencies for 16 of the 27 sites. However, the number of cycles at most sites was limited; except for two sites, the highest number of cycles was five. Only nine sites had a recovery efficiency above 10 percent for the first cycle, and 10 sites achieved a recovery efficiency above 30 percent during at least one cycle. The highest recovery efficiency achieved per cycle was 84 percent for cycle 16 at the Boynton Beach site.
Factors that could affect recovery of freshwater varied widely between sites. The thickness of the open storage zone at all sites ranged from 45 to 452 feet. For sites with the storage zone in the Upper Floridan aquifer, transmissivity based on tests of the storage zones ranged from 800 to 108,000 feet squared per day, leakance values indicated that confinement is not good in some areas, and the chloride concentration of ambient water ranged from 500 to 11,000 milligrams per liter.
Based on review of four case studies and data from other sites, several hydrogeologic and design factors appear to be important to the performance of aquifer storage and recovery in the Floridan aquifer system. Performance is m aximized when the storage zone is thin and located at the top of the Upper Floridan aquifer, and transmissivity and salinity of the storage zone are moderate (less than 30,000 feet squared per day and 3,000 milligrams per liter of chloride concentration, respectively). The structural setting at a site could also be important because of the potential for updip migration of a recharged freshwater bubble due to density contrast or loss of overlying confinement due to deformation.
Analysis of water-quality trends at two discharge stations; one within Big Cypress National Preserve and one near Biscayne Bay; southern Florida, 1966-94
Released October 13, 2021 12:30 EST
2000, Water-Resources Investigations Report 2000-4099
An analysis of water-quality trends was made at two U.S. Geological Survey daily discharge stations in southern Florida. The ESTREND computer program was the principal tool used for the determination of water-quality trends at the Miami Canal station west of Biscayne Bay in Miami and the Tamiami Canal station along U.S. Highway 41 in the Big Cypress National Preserve in Collier County. Variability in water quality caused by both seasonality and streamflow was compensated for by applying the nonparametric Seasonal Kendall trend test to unadjusted concentrations or flow-adjusted concentrations (residuals) determined from linear regression analysis. Concentrations of selected major inorganic constituents and physical characteristics; pH and dissolved oxygen; suspended sediment; nitrogen, phosphorus, and carbon species; trace metals; and bacteriological and biological characteristics were determined at the Miami and Tamiami Canal stations. Median and maximum concentrations of selected constituents were compared to the Florida Class III freshwater standards for recreation, propagation, and maintenance of a healthy, well-balanced population of fish and wildlife. The median concentrations of the water-quality constituents and characteristics generally were higher at the Miami Canal station than at the Tamiami Canal station. The maximum value for specific conductance at the Miami Canal station exceeded the State standard. The median and maximum concentrations for ammonia at the Miami and Tamiami Canal stations exceeded the State standard, whereas median dissolved-oxygen concentrations at both stations were below the State standard. Trend results were indicative of either improvement or deterioration in water quality with time. Improvement in water quality at the Miami Canal station was reflected by downward trends in suspended sediment (1987-94), turbidity, (1970-78), total ammonia (1971-94), total phosphorus (1987-94), barium (1978-94), iron (1969-94), and fecal coliform (1976-94). Deterioration in water quality at the same station was indicated by upward trends in specific conductance (1966-94), dissolved solids (1966-94, 1976-94, and 1987-94), chloride (1966-94), potassium (1966-94), magnesium (1966-94), sodium (1966-94), sulfate (1966-94), silica (1966-94), suspended sediment (1974-94), total organic carbon (1970-81), and fecal streptococcus (1987-94). The downward trend in pH (1966-94) was indicative of deterioration in water quality at the Miami Canal station. Improvement in water quality at the Tamiami Canal station was reflected by downward trends in fluoride (1967-93), total ammonia (1970-92), total nitrite plus nitrate (1975-85), and barium (1978-93). Deterioration in water quality at the same station was statistically significant by upward trends in specific conductance (1967-93), dissolved solids (1967-93), chloride (1967-93), sodium (1967-93), potassium (1967-93), magnesium (1967-93), strontium (1967-93), and suspended sediment (1976-93). The downward trend in dissolved oxygen (1970-93) was indicative of deterioration in water quality.
Surface-Water and Ground-Water Interactions in the Central Everglades, Florida
Released October 13, 2021 12:25 EST
2004, Scientific Investigations Report 2004-5069
Judson W. Harvey, Jessica T. Newlin, James M. Krest, Jungyill Choi, Eric A. Nemeth, Steven L. Krupa
Recharge and discharge are hydrological processes that cause Everglades surface water to be exchanged for subsurface water in the peat soil and the underlying sand and limestone aquifer. These interactions are thought to be important to water budgets, water quality, and ecology in the Everglades. Nonetheless, relatively few studies of surface water and ground water interactions have been conducted in the Everglades, especially in its vast interior areas. This report is a product of a cooperative investigation conducted by the USGS and the South Florida Water Management District (SFWMD) aimed at developing and testing techniques that would provide reliable estimates of recharge and discharge in interior areas of WCA-2A (Water Conservation Area 2A) and several other sites in the central Everglades. The new techniques quantified flow from surface water to the subsurface (recharge) and the opposite (discharge) using (1) Darcy-flux calculations based on measured vertical gradients in hydraulic head and hydraulic conductivity of peat; (2) modeling transport through peat and decay of the naturally occurring isotopes 224Ra and 223Ra (with half-lives of 4 and 11 days, respectively); and (3) modeling transport and decay of naturally occurring and "bomb-pulse" tritium (half-life of 12.4 years) in ground water. Advantages and disadvantages of each method for quantifying recharge and discharge were compared. In addition, spatial and temporal variability of recharge and discharge were evaluated and controlling factors identified. A final goal was to develop appropriately simplified (that is, time averaged) expressions of the results that will be useful in addressing a broad range of hydrological and ecological problems in the Everglades. Results were compared with existing information about water budgets from the South Florida Water Management Model (SFWMM), a principal tool used by the South Florida Water Management District to plan many of the hydrological aspects of the Everglades restoration.
Water Flow and Nutrient Flux from Five Estuarine Rivers along the Southwest Coast of the Everglades National Park, Florida, 1997-2001
Released October 13, 2021 12:25 EST
2004, Scientific Investigations Report 2004-5142
Discharge and nutrient fluxes for five tidally affected streams were monitored and evaluated as a part of the U.S. Geological Survey Place-Based Studies Initiative and the U.S. Department of the Interior Critical Ecosystem Studies Initiative. Locations on Lostmans Creek, and Broad, Harney, Shark, and North Rivers were selected using the criterion that a large amount of the water that flows through Shark River Slough must pass these sites. Discharge and nutrient-concentration data collection started at the Broad, Harney, and Shark River stations in January 1997 and ended in early 2001. Discharge and nutrient-concentration data collection started at the Lostmans Creek and North River stations in April 1999 and ended in early 2001. Each station was equipped with a vertically oriented acoustic-velocity sensor, water-level pressure transducer, bottom water-temperature thermistor, and specific conductance four-electrode sensor. Data collected using a vessel-mounted acoustic discharge measurement system were used to calibrate regression models of the mean river velocities and the in-situ index velocities. Information from these stations, in conjunction with data from other ongoing studies, will help to determine environmental effects on the southwest coast estuaries as changes in water management of the Everglades National Park continue.
Discharges from the Lostmans Creek, and Broad, Harney, Shark, and North River stations are influenced by semidiurnal tides, meteorological events, and surface- and ground-water inflow. Each of the five rivers is usually well mixed, having no greater than 500 microSiemens per centimeter at 25? Celsius difference in specific conductance from top to bottom during flood and ebb tides. Instantaneous flood discharges (water moving upstream) are typically of greater magnitude and shorter duration than instantaneous ebb discharges (water moving downstream).
Instantaneous discharge data were filtered using a low-pass filter to remove predominant tidal frequencies, and the filtered data were used to compute daily mean and monthly mean residual discharges. Lostmans Creek, and Broad, Harney and Shark Rivers each contributed from 20 to 27 percent of the total measured discharge to the Gulf of Mexico, whereas North River contributed approximately 4 percent. The main discharge region of the Shark River Slough extends from as far north as Lostmans Creek to as far south as North River. North River discharge has similar response characteristics to the other four rivers measured, but with a lesser magnitude of discharge. Comparisons of monthly mean discharges from the Tamiami Canal flow control structures S-12-A, B, C, and D located on U.S. Highway 41 (Tamiami Trail) to the five station total monthly mean discharges indicate that the discharges from the five rivers are approximately 2 to 3 times the S-12-A, B, C, D discharges, and that the measured southwest coast discharge peaks lead the S-12-A, B, C, D discharge peaks by approximately 1 month.
Residual total nitrogen and total phosphorus fluxes were estimated using linear regression models of discharge and flux. Monthly mean total nitrogen residual fluxes for the five southwest coast rivers ranged from approximately 0 to 390 short tons, whereas monthly mean total phosphorus residual fluxes ranged from approximately 0 to 6 short tons. Total nitrogen and total phosphorus residual fluxes at Lostmans Creek, and Broad, Harney, and Shark Rivers were similar in magnitude, each accounting for between 20 to 29 percent of the total measured residual flux. North River contributed between 3 to 4 percent of the total nitrogen and total phosphorus residual flux from the five rivers.
Major-ion and selected trace-metal chemistry of the Biscayne Aquifer, Southeast Florida
Released October 13, 2021 11:05 EST
1991, Water-Resources Investigations Report 91-4009
M.J. Radell, B.G. Katz
The major-ion and selected trace-metal chemistry of the Biscayne aquifer was characterized as part of the Florida Ground-Water Quality Monitoring Network Program, a multiagency cooperative effort concerned with delineating baseline water quality for major aquifer systems in the State. The Biscayne aquifer is unconfined and serves as the sole source of drinking water for more than 3 million people in southeast Florida. The Biscayne aquifer consists of highly permeable interbedded limestone and sandstone of Pleistocene and Pliocene age underlying most of Dade and Broward Counties and parts of Palm Beach and Monroe Counties. The high permeability is largely caused by extensive carbonate dissolution.
Water sampled from 189 wells tapping the Biscayne aquifer was predominantly a calcium bicarbonate type with some mixed types occurring in coastal areas and near major canals. Major - ion is areally uniform throughout the aquifer. According to nonparametric statistical tests of major ions and dissolved solids, the concentrations of calcium, sodium, bicarbonate, and dissolved solids increased significantly with well depth ( 0.05 significance level ), probably a result of less circulation at depth. Potassium and nitrate concentrations decreased significantly with depth. Although the source of recharge to the aquifer varies seasonally, there was no statistical difference in the concentration of major ions in pared water samples from 27 shallow wells collected during wet and dry seasons.
Median concentrations for barium, chromium, copper, lead, and manganese were below maximum or secondary maximum contaminant levels set by the US Environmental Protection Agency. The median iron concentration only slightly exceeded the secondary maximum contaminant level. The concentration of barium was significantly related (0.05 significance level) to calcium and bicarbonate concentration. No distinct areal pattern or vertical distribution of the selected trace metals was evident in water from the Biscayne aquifer. Sources for trace metals found in water from the Biscayne aquifer may include local contamination, well-construction techniques, canal - aquifer interactions, and natural occurrence in area soils and rock.
Hydrogeology of the surficial aquifer system, Dade County, Florida
Released October 13, 2021 11:05 EST
1991, Water-Resources Investigations Report 90-4108
J.E. Fish, M.T. Stewart
An investigation of the surficial aquifer system in Dade County, begun in 1983, is part of a regional study of the aquifer system in southeastern Florida. Test drilling for lithologic samples, flow measurements during drilling, aquifer testing, and analyses of earlier data permitted delineation of the hydraulic conductivity distribution (on hydrogeologic sections), the aquifers in the system, the generalized transmissivity distribution, and interpretation of the ground-water flow system.
The surficial aquifer system, in which an unconfined ground-water flow system exists, is composed of the sediments from land surface downward to the top of a regionally extensive zone of sediments of low permeability called the intermediate confining unit. The aquifer system units, which vary in composition from clay-size sediments to cavernous limestone, are hydro stratigraphically divided into the Biscayne aquifer at the top; an intervening semiconfining unit that consists principally of clayey sand; a predominantly gray limestone aquifer in the Tamiami Formation in western and west-central Dade County; and sand or clayey sand near the base of the surficial aquifer system. The base of the surficial aquifer system ranges from a depth of about 175 to 210 feet below land surface in westernmost Dade County to greater than 270 feet in northeastern Dade County. Test drilling and aquifer-test data indicate a complex hydraulic conductivity distribution. Hydraulic conductivities of the very highly permeable zone of the Biscayne aquifer commonly exceed 10,000 feet per day; in the gray limestone aquifer, they range from 210 to 780 feet per day.
Transmissivities of the surficial aquifer system vary locally but have a recognizable areal trend. Estimated values generally are about 300,000 feet squared per day or greater in nearly all of central and eastern Dade County. Transmissivity is lower to the west, decreasing to less than 75,000 feet squared per day in western Dade County. High transmissivity usually is associated with thick sections of the Fort Thompson Formation within the Biscayne aquifer. The gray limestone aquifer of the Tamiami Formation has transmissivities that range from 5,800 to 39,000 feet squared per day in western Dade County. The transition from high transmissivity to relatively low transmissivity is often only a few miles wide and coincides with the decrease in thickness of the very highly permeable Fort Thompson Formation, which marks the western boundary of the Biscayne aquifer.
More effective drainage as a result of extensive canal systems and large-scale pumping from municipal well fields has greatly altered the predevelopment flow system in eastern Dade County by: (1) eliminating or greatly reducing a seasonal and coastal ground-water ridge; (2) reducing deep circulation; (3) reducing or eliminating seasonal westward movement of ground water; (4) causing accelerated stormwater runoff and short ground-water flow paths; and (5) generally lowering the water table and inducing saltwater intrusion. Under predevelopment conditions in western Dade County, water entered the gray limestone aquifer by lateral movement from Broward and Collier Counties, and by downward seepage from The Everglades and the Biscayne aquifer, and moved southward and southeastward into Dade County to coastal discharge areas. Circulation in the Biscayne aquifer inland also was primarily to the south and southeast. In eastern Dade County, the seasonal ground-water ridge that formed under predevelopment conditions supported both easterly and westerly ground-water flow away from the ridge axis. This seasonal flow created a zone of lower dissolved solids.
Hydrologic effects of well-field operations in a wetland, Dade County, Florida
Released October 13, 2021 11:05 EST
1990, Water-Resources Investigations Report 90-4143
R.S. Sonenshein, R.H. Hofstetter
Water-level, canal stage and discharge, and rainfall data collected in a wetland in Dade County, Florida, were analyzed to determine the effects of pumping at the Northwest Well Field on water levels in the wetland. The Northwest Well Field is the first major well field in south Florida to be operated in a wetland, away from saltwater intrusion and the potential for contamination caused by urbanization.
Duration curves were used to analyze trends in water levels for seven observation wells near the Northwest Well Field. One observation well is 5.5 miles north of the well field, three wells are outside the cone of depression of the well field, and three are within the cone of depression. The water level data were analyzed for four time periods that were determined by a double-mass analysis of cumulative rainfall and cumulative canal discharge. Before 1984, water levels in all seven wells were above land surface 25 to 50 percent of the time. Since the well field began operating in 1984, water levels in the three wells within the cone of depression have been above land surface less than 1 percent of the time. Water levels at the four wells outside the cone of depression showed no effect from pumping at the well field.
Water levels have declined in 30 percent of the 65- square mile study area since the well field began operating. In 15 percent of the area, water levels have been lowered below land surface.
Water-resources potential of the freshwater lens at Key West, Florida
Released October 13, 2021 11:05 EST
1990, Water-Resources Investigations Report 90-4115
The island of Key West lies at the end of the Florida Keys, about 150 miles southwest of Miami. The public-water supply for the island is provided by the Florida Keys Aqueduct Authority Well Field near Miami. However, there are many privately owned wells on the island that tap the local fresh ground-water lens for potable and nonpotable water supply. The number of people who use water from the wells for drinking purposes is unknown.
From 1985 to 1988, the U.S. Geological Survey, in cooperation with the South Florida Water Management District, conducted an investigation to characterize the Key West freshwater lens. Observation wells were drilled to determine the extent of the lens and to characterize the water quality. Previous well logs and well-core data collected during the investigation showed the aquifer to be a highly permeable, porous, solution-riddled, oolitic limestone that allows rainfall recharge to quickly seep into the ocean and saltwater to easily intrude the aquifer.
The small freshwater lens (250 milligrams per liter of chloride concentration, or less) averages 5 feet in thickness below the center of the western half (Old Town) of the island. The lens contains about 20 million gallons of fresh-water during the dry season and about 30 million gallons during the wet season. Underlying the freshwater lens is a transition zone of freshwater-saltwater mix that extends to the saltwater interface (19,000 milligrams per liter of chloride concentration), which is about 40-feet deep at the center of the lens. The water table fluctuates and the configuration of the lens constantly changes, largely as a result of tidal effects. Other events, such as rainfall, pumping, and evapotranspiration, are masked by the tidal effects.
The freshwater lens is a calcium bicarbonate water that grades to a sodium chloride type near the saltwater interface. Elevated concentrations of nitrate nitrogen were found in water samples from wells in the Old Town district. However, concentrations generally were not above the maximum contaminant level of 10 milligrams per liter for drinking water established by the Florida Department of Environmental Regulation. Water samples near an old land-fill in the eastern half of the island had concentrations of iron (600-1,900 micrograms per liter) and lead (40-800 micrograms per liter) that extended maximum contaminant levels of 300 and 50 micrograms per liter. These trace-element concentrations generally decreased with distance from the landfill.
Although the freshwater lens is a potential source of water for additional nonpotable water needs in Key West, any large-scale pumping could quickly exhaust the freshwater lens, and saline water could be rapidly drawn though the porous limestone aquifer. Water-quality data indicate that the lens is an unlikely source of potable water.
A method to estimate canal leakage to the Biscayne Aquifer, Dade County, Florida
Released October 13, 2021 11:05 EST
1990, Water-Resources Investigations Report 90-4135
The leakage characteristics of channels that partially penetrate the Biscayne aquifer and have reduced bed permeability were studied. Leakage characteristics were described in terms of a reach transmissivity-defined as the volume flow rate out of the channel per unit length of the channel per unit drawdown, where drawdown is defined as the difference in altitude between the water surface in the canal and the water table in the adjacent aquifer. A theoretical expression was developed to relate the reach transmissivity to the transmissivity of the formation, mean channel width, distance of drawdown measurement from the channel centerline, ratio of drawdowns on both sides of the channel, and local reach transmissivity associated with reduced bed permeability. This theoretical expression was verified using a fine-scale numerical model, which gave accurate results when drawdowns were measured beyond 10 aquifer depths from the side of the channel. Using the theoretical formulation, it is shown that the reach transmissivity employed in regional ground-water models, which are based on average drawdowns within a cell, depends on the size of the cell as well as the transmissivity of the formation, channel width, and local reach transmissivity due to reduced bed permeability.
The theoretical reach transmissivity function was compared with field measurements at L-31N Canal and Snapper Creek Extension Canal in Dade County, Florida. Analyses of the data for both canals showed good agreement between the estimated and measured reach transmissivities. At L- 31N Canal, field measurements indicated that the local reach transmissivity was relatively uniform over a 2-mile reach of the channel (averaging 630 cubic feet per second per mile per foot), and the formation transmissivity was 1.8 x106 feet squared per day. At Snapper Creek Extension Canal, an approximate analysis was necessary due to the inability of the acoustic velocity meter to measure very low water velocities in the channel. Assuming an aquifer transmissivity of 1 x 106 feet squared per day, drawdown measurements indicated that the local reach transmissivity was about 400 cubic feet per second per mile per foot. The theoretical relation, combined with the local reach transmissivity and formation transmissivity, was sufficient to predict the leakage out of L-31N Canal and Snapper Creek Extension Canal for any drawdown scenario.
Hydrogeology and the Distribution and Origin of Salinity in the Floridan Aquifer System, Southeastern Florida
Released October 13, 2021 11:00 EST
1994, Water-Resources Investigations Report 94-4010
Ronald S. Reese
The Floridan aquifer system in southeastern Florida consists of the Upper Floridan aquifer, the middle confining unit, and the Lower Floridan aquifer. An upper zone of brackish water and a lower zone of water with a salinity similar to that of seawater are present in the Floridan aquifer system. The brackish-water zone is defined as that in which water has a dissolved-solids concentration of less than 10,000 milligrams per liter (chloride concentration less than about 5,240 milligrams per liter), and water in the the saline-water zone has a dissolved solids concentration of about 35,000 milligrams per liter (about 18,900 milligrams per liter chloride concentration). The brackish-water and saline-water zones are separated by a transitional zone, typically 100 feet thick, in which salinity increases abruptly with depth. The base of the brackish-water zone lies within the Upper Floridan aquifer along the coast but extends into the middle confining unit inland. The brackish- water zone is as much as 1,200 feet thick inland, whereas the Upper Floridart aquifer is typically 500 to 600 feet thick. Changes in lithology or permeability do not usually control the position of the boundary between the brackish-water and saline-water zones. Calculations of the depth of a brackish-water and saline-water interface using the Ghyben-Herzberg relation show good agreement between calculated and actual positions of the interface, indicating equilibrium between the zones. Several areas of high salinity with chloride concentrations greater than 3,000 milligrams per liter are present in the upper interval of the brackish-water zone near the coast, and in one of these areas in northeastern Broward County, salinity decreases with depth from the upper to lower interval. The high salinities could be a result of seawater preferentially encroaching into zones of higher permeability in the Upper Flofidan aquifer during Pleistocene high stands of sea level and incomplete flushing of the seawater by the present-day flow system.
Effects of horizontal velocity variations on ultrasonic velocity measurements in open channels
Released October 13, 2021 11:00 EST
1992, Water-Resources Investigations Report 91-4200
Use of an ultrasonic velocity meter to determine discharge in open channels involves measuring the velocity in a line between transducers in the stream and relating that velocity to the average velocity in the stream. The standard method of calculating average velocity in the channel assumes that the velocity profile in the channel can be represented by the one-dimensional von Karman universal velocity profile. However, the velocity profile can be described by a two-dimensional equation that accounts for the horizontal velocity variations induced by the channel sides.
An equation to calculate average velocity accounts for the two-dimensional variations in velocity within a stream. The use of this new equation to calculate average velocity was compared to the standard method in theoretical trapezoidal cross sections and in the L-31N and Snapper Creek Extension Canals near Miami, Florida. These comparisons indicate that the two-dimensional variations have the most significant effect in narrow, deep channels. Also, the two-dimensional effects may be significant in some field situations and need to be considered when determining average velocity and discharge with an ultrasonic velocity meter.
Hydrogeology and Migration of Septic-Tank Effluent in the Surficial Aquifer System in the Northern Midlands Area, Palm Beach County, Florida
Released October 13, 2021 11:00 EST
1992, Water-Resources Investigations Report 91-4175
Wesley L. Miller
The northern Midlands area in Palm Beach County is an area of expected residential growth, but its flat topography, poor drainage, and near-surface marl layers retard rainfall infiltration and cause frequent flooding. Public water supplies and sewer services are not planned for the area, thus, residents must rely on domestic wells and septic tanks. The water table in the northern Midlands area is seldom more than 5 feet below land surface, and regional ground-water flows are east, southwest, and south from the north-central part of the area where ground-water levels are highest. Ground-water quality in the western part of the area and in the Loxahatchee Slough is greatly influenced by residual seawater emplaced during the Pleistocene Epoch. Chloride and dissolved-solids concentrations of ground water in the surficial aquifer system in these areas often exceed secondary drinking-water standards. Residual seawater has been more effectively flushed from the more permeable sediments elsewhere in the eastern and southwestern parts of the study area. Test at three septic-tank sites showed traces of effluent in ground water (38-92 feet from the septic tank outlets) and that near-surface marl layers greatly impede the downward migration of the effluent in the surficial aquifer system throughout the northern midlands.
Effects of dried wastewater-treatment sludge application on ground-water quality in South Dade County, Florida
Released October 13, 2021 11:00 EST
1992, Water-Resources Investigations Report 91-4135
Four test fields in the south Dade agricultural area were studied to determine the effects of sludge application on ground-water quality. Two fields had been cultivated for 10 years or more, and two had not been farmed for at least 10 years. The fields were representative of the area's two soil types (Rockdale and Perrine marl) and two major crop types (row crops and groves). Before the application of sludge, wells upgradient of, within, and downgradient of each field were sampled for possible sludge contaminants at the end of wet and dry seasons. Municipal wastewater treatment sludge from the Dade County Water and Sewe Authority Department was then applied to the fields at varying application rates. The wells at each field were sampled over a 2-year period under different hydrologic conditions for possible sludge-related constituents (specific conductance, pH, alkalinity, nitrogen, phosphorus, total organic carbon, copper, iron, magnesium, manganese, potassium, zinc, arsenic, cadmium, chloride, chromium, lead, mercury, nickel, and sodium). Comparisons were made between water quality in the vicinity of the test fields and Florida Department of Environmental Regulation primary and secondary drinking-water regulations, an between water quality upgradient of, beneath, and downgradient of the fields. Comparisons between presludge and postsludge water quality did not indicate any improvement because of retention of agrichemicals by the sludge nor did they indicate any deterioration because of leaching from the sludge. Comparisons of water quality upgradient of the fields to water quality beneath and downgradient of the fields also did not indicate any changes related to sludge. Florida Department of Environmental Regulation primary and secondary drinking-water regulations wer exceeded at the Rockdale maximum-application field by mercury (9.5 ug/L (micrograms per liter)), and the Perrine marl maximum-application field by manganese (60 ug/L) and lead (85 ug/L), and at the Perrine marl row-crop field by mercury (5.2 ug/L). All other exceedances were either in presludge or upgradient samples, or they were for constituents or properties, such as iron and color, which typically exceed standards in native ground water. Acid-extractable and base-neutral compounds, volatile organic compounds, chlorophenoxy herbicides, organophosphorus insecticides, and organochlorine compounds were analyzed for one shallow well at each field twice annually. Those compounds that equaled or exceeded the detection limit after sludge was applied included benzene (0.3 and 1.2 ug/L), chloroform (0.2 and 0.3 ug/L), bis(2-Ethylhexyl)phthalate (29 and 42 ug/L), methylene chloride (14 ug/L), tolulene (0.2, 0.4, 0.5, 1.3, and 4.4 ug/L), 1, 1,1-trichloroethana (0.6 ug/L), trichloroethylene (0.3 ug/L), 2.4-D (0.01 ug/L), and xylene (0.3 ug/L). It ws not possible to ascertain the origin of these compounds because they are available from sources other than sludge.
Methodology for estimating nutrient loads discharged from the east coast canals to Biscayne Bay, Miami-Dade County, Florida
Released October 13, 2021 10:55 EST
1999, Water-Resources Investigations Report 99-4094
Arthur C. Lietz
Biscayne Bay is an oligotrophic, subtropical estuary located along the southeastern coast of Florida that provides habitat for a variety of plant and animal life. Concern has arisen with regard to the ecological health of Biscayne Bay because of the presence of nutrient-laden discharges from the east coast canals that drain into the bay. This concern, as well as planned diversion of discharges for ecosystem restoration from the urban and agricultural corridors of Miami-Dade County to Everglades National Park, served as the impetus for a study conducted during the 1996 and 1997 water years to estimate nutrient loads discharged from the east coast canals into Biscayne Bay. Analytical results indicated that the highest concentration of any individual nutrient sampled for in the study was 4.38 mg/L (milligrams per liter) for nitrate at one site, and the lowest concentrations determined were below the detection limits for orthophosphate at six sites and nitrite at four sites. Median concentrations for all the sites were 0.75 mg/L for total organic nitrogen, 0.10 mg/L for ammonia, 0.02 mg/L for nitrite, 0.18 mg/L for nitrate, 0.20 mg/L for nitrite plus nitrate nitrogen, 0.02 mg/L for total phosphorus, and 0.005 mg/L for orthophosphate. The maximum total phosphorus concentration of 0.31 mg/L was the only nutrient concentration to exceed U.S. Environmental Protection Agency (1986) water-quality criteria. High concentrations of total phosphorus usually reflect contamination as a result of human activities. Five sites exceeded the fresh-water quality standard of 0.5 mg/L for ammonia concentration as determined by the Miami-Dade County Department of Environmental Resources Management. Median total organic nitrogen concentrations were higher in urban and forested/wetland areas than in agricultural areas; median concentrations of nitrite, nitrate, and nitrite plus nitrate nitrogen were higher in agricultural areas than in urban and forested/wetland areas; and ammonia, total phosphorus, and orthophosphate concentrations were higher in urban areas than in agricultural and forested/wetland areas. These results coincide with expected differences in nutrient concentrations based on knowledge of point and nonpoint source influences and nutrient cycling. The Wilcoxon signed ranks test (WSRT) was used to compare differences between point (grab) samples and depth-integrated samples for total nitrogen and total phosphorus concentrations at 12 east coast canal sites. Statistically significant differences (alpha level of 0.025) in total phosphorus concentrations between point (grab) samples collected 1.0 meter deep and depth-integrated samples were detected at three sites. One site also showed statistically significant differences in total phosphorus concentrations between point (grab) samples collected 0.5 meter deep and depth-integrated samples. There were no statistically significant differences in total nitrogen and total phosphorus concentrations between point (grab) samples collected 0.5 meter deep and 1.0 meter deep for all the sites. Results of the line of organic correlation, a fitting procedure used to compare point (grab) and depth-integrated samples where statistically significant differences exist as defined by the WSRT, indicated that point (grab) samples underestimate total phosphorus concentrations when compared to depth-integrated samples. This underestimation probably can be attributed to the reduced suspended-sediment concentrations near the surface during periods of flow as compared to those near the streambed. Predictive models were developed to estimate total nitrogen and total phosphorus loads by means of an ordinary least-squares regression technique. Instantaneous discharge was used as the independent variable, and total phosphorus load or total nitrogen load represented the dependent variable. A software program called Estimator was used to develop the regression models and to compute total nitrogen and total phosphorus loads
Assessment of saltwater intrusion in southern coastal Broward County, Florida
Released October 13, 2021 10:55 EST
1996, Water-Resources Investigations Report 96-4221
Of the counties in southeastern Florida, Broward County has experienced some of the most severe effects of saltwater intrusion into the surficial Biscayne aquifer because, before 1950, most public water-supply well fields in the county were constructed near the principal early population centers located less than 5 miles from the Atlantic Ocean. The construction of major regional drainage canals in the early 20th century caused a lowering of the water table and a gradual inland movement of the saltwater front toward the well fields. The U.S. Geological Survey began field investigations of saltwater intrusion in the Biscayne aquifer of southeastern Broward County in 1939. As part of the present study, the positions of the saltwater front in 1945, 1969, and 1993 were estimated using chloride concentrations of water samples collected between 1939 and 1994 from various monitoring and exploratory wells. The data indicate that, between 1945 and 1993, the saltwater front has moved as much as 0.5 mile inland in parts of the study area. The position and movement of the saltwater front were simulated numerically to help determine which of the various hydrologic factors and water-management features characterizing the coastal subsurface environment and its alteration by man are of significance in increasing or decreasing the degree of saltwater intrusion. Two representational methods were applied by the selection and use of appropriate model codes. The SHARP code simulates the position of the saltwater front as a sharp interface, which implies that no transition zone (a zone in which a gradational change between freshwater and saltwater occurs) separates freshwater and saltwater. The Subsurface Waste Injection Program (SWIP) code simulates a two-fluid, variable-density system using a convective-diffusion approach that includes a representation of the transition zone that occurs between the freshwater and saltwater bodies. The models were applied to: (1) approximately replicate predevelopment and current positions of the interface in the study area; and (2) study the relative importance of various factors affecting the interface position. The model analyses assumed a conceptual model of uniform easterly flow in the aquifer toward points of offshore discharge to tidewater. Measurements of water-table altitude and the depth to the interface in the study area exhibit an interrelation that differes substantially from the classical Ghyben-Herzberg relation. However, both model codes simulated water-table altitudes and interface positions that were generally consistent with the Ghyben-Herzberg relation but differed substantially from observed data. The simulate interface positions were inland of the known positions, and simulate water-table altitudes were higher than measured ones. The SHARP and SWIP simulations were in general agreement with each other when a low value of longitudinal dispersivity was specified in the SWIP simulation and also for higher values of longitudinal dispersivity when modified dispersion algorithms were used in SWIP that greatly reduced the simulated degree of vertical dispersion. Sensitivity analyses performed using the SHARP code indicated simulation results to be relatively insensitive to a substantial change in the specified slope of the base of the aquifer and moderately sensitive to a 150-percent change in net atmospheric recharge to the aquifer (rainfall minus evapotranspiration). Representing well-field pumping by the City of hallandale had only a minor, localized influence on the simulated regional interface position. Using various cross-sectional grid designs in applications of the SWIP code, near convergence of all lines of equal concentrations in the transition zone was achieved within a simulation time of 10 years. The simulated equilibrium interface location was sensitive to substantial spatial variations in the specified hydraulic conductivity values, but was relatively insensitive to seasonal varying
Preliminary assessment of injection, storage, and recovery of freshwater in the lower Hawthorn aquifer, Cape Coral, Florida
Released October 13, 2021 10:55 EST
1995, Water-Resources Investigations Report 94-4121
Vicente Quinones-Aponte, Eliezer J. Wexler
A preliminary assessment of subsurface injection, storage and recovery of fresh canal water was made in the naturally brackish lower Hawthorn aquifer in Cape Coral, southwestern Florida. A digital modeling approach was used for this preliminary assessment, incorporating available data on hydrologic conditions, aquifer properties, and water quality to simulate density-dependent ground-water flow and advective-dispersive transport of a conservative ground-water solute (chloride ion).
A baseline simulation was used as reference to compare the effects of changing various operational factors on the recovery efficiency. A recovery efficiency of 64 percent was estimated for the baseline simulation. Based on the model, the recovery efficiency increases if the injection rate and recovery rates are increased and if the ratio of recovery rate to injection rate is increased. Recovery efficiency decreases if the amount of water injected is increased; slightly decreases if the storage time is increased; is not changed significantly if the water is injected to a specific flow zone; increases with successive cycles of injection, storage, and recovery; and decreases if the chloride concentrations in either the injection water or native aquifer water are increased. In everal hypothetical tests, the recovery efficiency fluctuated between 22 and about 100 percent.
Two successive cycles could bring the recovery efficiency from 60 to about 80 percent. Interlayer solute mass movement across the upper and lower boundaries seems to be the most important factor affecting the recovery efficiency. A sensitivity analysis was performed applying a technique in which the change in the various factors and the corresponding model responses are normalized so that meaningful comparisons among the responses could be made. The general results from the sensitivity analysis indicated that the permeabilities of the upper and lower flow zones were the most important factors that produced the greatest changes in the relative sensitivity of the recovery efficiency. Almost equally significant changes occurred in the relative sensitivity of the recovery efficiency when all porosity values of the upper and lower flow zones and the leaky confining units and the vertical anisotropy ratio were changed.
The advective factors are the most important in the Cape Coral area according to the sensitivity analysis. However, the dispersivity values used in the model were extrapolated from studies conducted at the nearby Lee County Water Treatment Plant, and these values might not be representative of the actual dispersive characteristics of the lower Hawthorn aquifer in the Cape Coral area.
Spatial and temporal statistical analysis of a ground-water level network, Broward County, Florida
Released October 13, 2021 10:55 EST
1994, Water-Resources Investigations Report 94-4076
E.D. Swain, R.S. Sonenshein
The U.S. Geological Survey has developed a method to evaluate the spatial and temporal statistics of a continuous ground-water level recorder network in Broward County, Florida. Because the Broward County network is sparse for most spatial statistics, a technique has been developed to define polygons for each well that represent the area monitored by the well within specified criteria. The boundaries of these "confidence polygons" are defined by the endpoints of radial lines oriented toward the other wells. The lengths of these lines are determined as the statistically estimated distances to the points at which ground-water levels can be predicted within specirfied criteria. The confidence polygons indicate: (1) the areal coverage of the network, (2) locations where data are unavailable, and (3) areas of redundant data collection. Comparison with data from a noncontinuous recorder well indicates that the confidence polygons are a good represen- tation of areal coverages. The temporal analysis utilizes statistical techniques similar to those used in the spatial method, defining variations in time rather than in space. Consequently, instead of defining radial distances to points, time intervals are defined over which water-level values can be predicted within a specified confidence. These "temporal confidence intervals" correspond to maximum allowable periods between field measure- ments. To combine all results from the analyses, a single coefficient reflecting the spatial and temporal results has been developed. The coefficient is referred to as the Spatial and Temporal Adequacy and Redundancy Evaluation (STARE) and is determined by three factors: the size of the confidence polygon, the number of times the well is part of a redundant pair, and the temporal confidence interval. This coefficient and the individual results of each analysis are used in evaluating the present network and determining future management decisions.
Rapa Nui (Easter Island) Rano Raraku crater lake basin: Geochemical characterization and implications for the Ahu-Moai Period
Released October 13, 2021 06:00 EST
2021, PLoS ONE (10)
Elena Argiriadis, Mara Bortolini, Natalie Kehrwald, Marco Roman, Clara Turetta, Shahpara Hanif, Evans Osayuki Erhendi, José Miguel Ramirez Aliaga, David B. McWethy, Amy E. Myrbo, Anibal Pauchard, Carlo Barbante, Dario Battistel
Hydrogeology and gain/loss assessment of two lakes contaminated with per- and polyfluoroalkyl substances, vicinity of Joint Base McGuire-Dix-Lakehurst, New Jersey, 2020–21
Rano Raraku, the crater lake constrained by basaltic tuff that served as the primary quarry used to construct the moai statues on Rapa Nui (Easter Island), has experienced fluctuations in lake level over the past centuries. As one of the only freshwater sources on the island, understanding the present and past geochemical characteristics of the lake water is critical to understand if the lake could have been a viable freshwater source for Rapa Nui. At the time of sampling in September 2017, the maximum lake depth was ~1 m. The lake level has substantially declined in the subsequent years, with the lake drying almost completely in January 2018. The lake is currently characterized by highly anoxic conditions, with a predominance of ammonium ions on nitrates, a high concentration of organic carbon in the water-sediment interface and reducing conditions of the lake, as evidenced by Mn/Fe and Cr/V ratios. Our estimates of past salinity inferred from the chloride mass balance indicates that it was unlikely that Rano Raraku provided a viable freshwater source for early Rapa Nui people. The installation of an outlet pipe around 1950 that was active until the late 1970s, as well as grazing of horses on the lake margins appear to have significantly impacted the geochemical conditions of Rano Raraku sediments and lake water in recent decades. Such impacts are distinct from natural environmental changes and highlight the need to consider the sensitivity of the lake geochemistry to human activities.
Released October 12, 2021 12:25 EST
2021, Scientific Investigations Report 2021-5107
Alex R. Fiore, Christopher M. Witzigman, Robert G. Reiser
Per- and polyfluoroalkyl substances (PFAS) have been identified in two lakes near Joint Base McGuire-Dix-Lakehurst (JBMDL) in New Jersey—Little Pine Lake in Pemberton Township and Pine Lake in Manchester Township. The streams that enter these lakes begin in or near JBMDL where sources of PFAS contamination are located. The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, performed a study of the hydrogeology and the gaining or losing conditions associated with these lakes.
Hydrogeologic characteristics in the vicinity of both lakes were assessed using qualitative vertical hydraulic profiling of the subsurface. Groundwater was pumped from test intervals at various depths below land surface, then groundwater levels were measured until they recovered to static conditions. Low permeability aquifer intervals were identified within the aquifer underlying both lakes, consistent with silty and (or) clayey subunits of the Kirkwood-Cohansey aquifer system indicated on geophysical and lithologic logs.
Gaining or losing conditions between groundwater and lake surface water were assessed with continuous monitoring of water levels and temperature in the lakes and in three piezometers per lake screened at different depths in the underlying aquifer from August 2020 through May 2021. At Little Pine Lake, surface water levels were consistently lower than groundwater levels, which is indicative of a gaining condition with groundwater flowing into the lake. Gaining conditions also support the lack of diurnal temperature fluctuations observed in groundwater, but poor response of surface-water temperature prevents complete analysis. The potential for losing conditions at other locations around Little Pine Lake necessitates further assessment in regard to possible PFAS contamination of groundwater in the underlying aquifer. Temperature results were inconclusive at Pine Lake, but surface water levels were consistently higher than groundwater levels throughout the monitoring period, which indicates a losing condition with lake water flowing into the underlying aquifer. Because of the downward vertical hydraulic gradient identified at Pine Lake, there is a strong possibility that PFAS in the lake water has also contaminated groundwater in its vicinity.
Past, present, and future of Mars Polar Science: Outcomes and outlook from the 7th International Conference on Mars Polar Science and Exploration
Released October 11, 2021 07:12 EST
2021, The Planetary Science Journal (2)
Patricio Becerra, Isaac B. Smith, Shannon M Hibbard, Chimira Andres, Jonathan Bapst, Ali Bramson, Peter Buhler, Andrea Coronato, Serina Diniega, Jeremy Emmett, Anna Grau Galofre, Clemence Herny, Melinda Kahre, J. Paul Knightly, Stefano Nerozzi, Alyssa Pascuzzo, Ganna Portyankina, Jorge Rabassa, Leslie Tamppari, Timothy N. Titus, Jennifer L Whitten, Zuriñe Yoldi
Acute oral toxicity and tissue residues of saxitoxin in the mallard (Anas platyrhynchos)
Mars Polar Science is a subfield of Mars science that encompasses all studies of the cryosphere of Mars and its interaction with the Martian environment. Every 4 yr, the community of scientists dedicated to this subfield meets to discuss new findings and debate open issues in the International Conference on Mars Polar Science and Exploration (ICMPSE). This paper summarizes the proceedings of the seventh ICMPSE and the progress made since the sixth edition. We highlight the most important advances and present the most salient open questions in the field today, as discussed and agreed upon by the participants of the conference. We also feature agreed-upon suggestions for future methods, measurements, instruments, and missions that would be essential to answering the main open questions presented. This work is thus an overview of the current status of Mars Polar Science and is intended to serve as a road map for the direction of the field during the next 4 yr and beyond, helping to shape its contribution within the larger context of planetary science and exploration.
Released October 09, 2021 07:35 EST
2020, Harmful Algae (109)
Robert J. Dusek, Matthew M. Smith, Caroline R. Van Hemert, Valerie I. Shearn-Bochsler, Sherwood Hall, Clark D. Ridge, Ransome Hardison, Robert Kaler, Barbara Bodenstein, Erik K. Hofmeister, Jeffrey S. Hall
Lessons learned from development of natural capital accounts in the United States and European Union
Released October 09, 2021 07:03 EST
2021, Ecosystem Services (52)
Kenneth J. Bagstad, Jane Carter Ingram, Carl D. Shapiro, Alessandra La Notte, Joachim Maes, Sara Vallecillo, Clyde F. Casey, Pierre D. Glynn, Mehdi Heris, Justin A. Johnson, Chris Lauer, John Matuszak, Kirsten L. L. Oleson, Stephen M. Posner, Charles R. Rhodes, Brian Voigt
Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2019
Released October 08, 2021 11:13 EST
2021, Open-File Report 2021-1079
Daniel J. Cain, Marie-Noële Croteau, Janet K. Thompson, Francis Parchaso, Robin Stewart, Kelly H. Shrader, Emily L. Zierdt Smith, Samuel N. Luoma
Trace-metal concentrations in sediment and in the clam Limecola petalum (formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by the U.S. Geological Survey (USGS) for the period January 2019 to December 2019. These data append to long-term datasets extending back to 1974. A major focus of the report is an integrated description of the 2019 data within the context of the longer, multidecadal dataset. This dataset supports the City of Palo Alto’s Near-Field Receiving-Water Monitoring Program, initiated in 1994.
Significant reductions in silver and copper contamination occurred at the site in the 1980s following the implementation by PARWQCP of advanced wastewater treatment and source control measures. Since the 1990s, concentrations of these elements in surface sediments have continued to decrease, although more slowly. Silver appears to have stabilized at concentrations about twice the regional background concentration. Presently, sediment copper concentrations appear to be near the regional background level. Over the same period (1994–2019), sedimentary iron and zinc also exhibited modest declines. Sedimentary aluminum, chromium, mercury, nickel, and selenium have not exhibited any trend. Since 1994, concentrations of silver and copper in L. petalum have varied seasonally, apparently in response to a combination of site-specific metal exposures and cyclic growth and reproduction, as reported previously. Seasonal patterns for other elements, including chromium, mercury, nickel, selenium, and zinc, were generally similar in timing and magnitude as those for silver and copper. The annual growth and reproductive cycle explained a small amount of the variance in annual silver and zinc tissue metal concentrations. However, interannual trends are not apparent for any element.
Biological effects of elevated silver and copper contamination at the Palo Alto site have been interpreted from data collected during and after the recession of these contaminants. Concentrations of both elements in the soft tissues of L. petalum declined with sedimentary copper and silver. This pattern was associated with changes in the reproductive activity of L. petalum, as well as the structure of the benthic invertebrate community. Reproductive activity of L. petalum increased as metal concentrations in L. petalum declined and presently is stable with almost all animals initiating reproduction in the fall and spawning the following spring. Analyses of the benthic community structure indicate that the infaunal invertebrate community has shifted from one dominated by several opportunistic species when silver and copper exposures were highest to one in which the species abundance is more evenly distributed, a pattern that indicates a more stable community that is subjected to fewer stressors. Importantly, this long-term change is unrelated to other metals and other measured environmental factors, including salinity and sediment composition. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals. Both species had short-lived rebounds in abundance in 2008, 2009, and 2010 and showed signs of increasing abundance in 2019. Heteromastus filiformis (a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying its eggs on or in the sediment) showed a concurrent increase in dominance and, in the last several years before 2008, showed a stable population. H. filiformis abundance increased slightly in 2011–2012 and returned to pre-2011 numbers in 2019.
An unidentified disturbance occurred on the mudflat in early 2008 that resulted in the loss of the benthic animals, except for deep-dwelling animals like L. petalum. However, within two months of this event, animals returned to the mudflat. The resilience of the community suggested that the disturbance was not caused by a persistent toxin or anoxia. The reproductive mode of most species that were present in 2019 was indicative of species that were available either as pelagic larvae or as mobile adults. Although oviparous species were lower in number in this group, the authors hypothesize that these species will return slowly as more species move back into the area. The use of functional ecology was highlighted in the 2019 benthic community data, which showed that the animals that have now returned to the mudflat are those that can respond successfully to a physical, nontoxic disturbance. Today, community data show a mix of species that consume the sediment, or filter feed, those that have pelagic larvae that must survive landing on the sediment, and those that brood their young. USGS scientists view the 2008 disturbance event as a response by the infaunal community to an episodic natural stressor (possibly sediment accretion or a pulse of freshwater), in contrast to the long-term recovery from metal contamination. We will compare this recovery to the long-term recovery observed after the 1970s when the decline in sediment pollutants was the dominating factor.
The climate envelope of Alaska’s northern treelines: Implications for controlling factors and future treeline advance
Released October 08, 2021 10:43 EST
Colin T. Maher, Roman J. Dial, Neal J Pastick, Rebecca E. Hewitt, M. Torre Jorgenson, Patrick F. Sullivan
Understanding the key mechanisms that control northern treelines is important to accurately predict biome shifts and terrestrial feedbacks to climate. At a global scale, it has long been observed that elevational and latitudinal treelines occur at similar mean growing season air temperature (GSAT) isotherms, inspiring the growth limitation hypothesis (GLH) that cold GSAT limits aboveground growth of treeline trees, with mean treeline GSAT ~6–7°C. Treelines with mean GSAT warmer than 6–7°C may indicate other limiting factors. Many treelines globally are not advancing despite warming, and other climate variables are rarely considered at broad scales. Our goals were to test whether current boreal treelines in northern Alaska correspond with the GLH isotherm, determine which environmental factors are most predictive of treeline presence, and identify areas beyond the current treeline where advance is most likely. We digitized ~12 400 km of treelines (>26 K points) and computed seasonal climate variables across northern Alaska. We then built a generalized additive model predicting treeline presence to identify key factors determining treeline. Two metrics of mean GSAT at Alaska's northern treelines were consistently warmer than the 6–7°C isotherm (means of 8.5°C and 9.3°C), indicating that direct physiological limitation from low GSAT is unlikely to explain the position of treelines in northern Alaska. Our final model included cumulative growing degree-days, near-surface (≤1 m) permafrost probability and growing season total precipitation, which together may represent the importance of soil temperature. Our results indicate that mean GSAT may not be the primary driver of treeline in northern Alaska or that its effect is mediated by other more proximate, and possibly non-climatic, controls. Our model predicts treeline potential in several areas beyond current treelines, pointing to possible routes of treeline advance if unconstrained by non-climatic factors.
Megafires and thick smoke portend big problems for migratory birds
Released October 08, 2021 06:36 EST
Cory T. Overton, Austen Lorenz, Eric P James, Ravan Ahmadov, John M. Eadie, Fiona McDuie, Mark J. Petrie, Chris A. Nicolai, Melanie L Weaver, Daniel A Skalos, Shannon Skalos, Andrea Lynn Mott, Desmond Alexander Mackell, Anna Kennedy, Elliott L. Matchett, Michael L. Casazza
Range eclipse leads to tenuous survival of a rare lizard species on a barrier atoll
In 2020, the fire season affecting the western United States reached unprecedented levels. The 116 fires active in September consumed nearly 20,822 km2 (https://inciweb.nwcg.gov/accessible-view/ Accessed 2020-09-29) with eighty percent of this footprint (16,567 km2) from 68 fires occurring within California, Oregon, and Washington. Although the 2020 fire season was the most extreme on record, it exemplified patterns of increased wildfire size, number, timing, return frequency, and extent which are linked to climate-driven changes in precipitation and temperature affecting fire ignition and severity (Westerling 2016, Goss et al. 2020, Weber and Yadav 2020).
Released October 08, 2021 06:24 EST
Jonathan Q. Richmond, Elijah Wostl, Robert Reed, R. N. Fisher
Evidence that copepod biomass during the larval period regulates recruitment of Lake Erie walleye
Rediscovery of living populations of a species that was presumed to be extirpated can generate new narratives for conservation in areas suffering from losses in biodiversity. We used field observations and DNA sequence data to verify the rediscovery of the Critically Endangered scincid lizard Emoia slevini on Dåno′, an islet off the coast of Guam in the southern Mariana Islands, where for > 20 years it had been considered possibly extirpated. Endemic to the Marianas, E. slevini has declined throughout its range and no longer occurs on as many as five islands from which it was historically known, most likely because of interactions with invasive species and loss of native forest. Our results show that individuals from Dåno′, the type locality for E. slevini, are genetically similar but not identical to E. slevini on Sarigan and Alamagan to the north, and that E. slevini is a close evolutionary relative to another congener in the southern Marianas that is currently recognized as Emoia atrocostata but probably represents an undescribed species in this archipelago. We also show that other, more broadly distributed species of Emoia occurring on Dåno′ are distant relatives to E. slevini and the Mariana lineage of E. atrocostata, providing further evidence of the distinctiveness of these taxa. The rediscovery of E. slevini on Dåno′ following rodent eradication and culling of a population of monitor lizards suggests that management of invasive species is key to the recovery of this skink in the Mariana Islands, and that a range eclipse on the larger neighbouring island of Guam best explains why the rediscovery took place at the periphery of the species’ historic range. A Chamorro abstract can be found in the supplementary material.
Released October 07, 2021 11:23 EST
2021, Journal of Great Lakes Research
Cassandra J. May, R. Budnik, S. Ludsin, D. O'Donnell, James M. Hood, Edward F. Roseman, E. Marschall
Walleye (Sander vitreus) is an economically and culturally important species in Lake Erie that has experienced large interannual variability in recruitment. We examined the importance of prey biomass during the larval period to walleye recruitment while also considering the importance of temperature. Using nine years of field data over a 22-year period (1994–2016) for larval walleye and zooplankton, we found that strong recruitment events occurred in years when the biomass (dry µg L-1) of copepods (e.g., calanoids, cyclopoids) was greater during the spring larval period. Conversely, the biomass of cladocerans and mean spring water temperatures were poor predictors of walleye recruitment. Our results highlight the need to consider zooplankton availability during the larval period when seeking to understand the recruitment dynamics of freshwater fish populations such as Lake Erie walleye.
Anthropogenic landcover impacts fluvial dissolved organic matter composition in the Upper Mississippi River Basin
Released October 07, 2021 07:44 EST
Derrick R. Vaughn, Anne M. Kellerman, Kimberly Wickland, Robert G. Striegl, David C. Podgorski, Jon R. Hawkings, Jaap Nienhuis, Mark Dornblaser, Edward G. Stets, Robert GM Spencer
Water-quality distributions in the East Branch Black River near the Chemical Recovery Systems site in Elyria, Ohio, 2021
Landcover changes have altered the natural carbon cycle; however, most landcover studies focus on either forest conversion to agriculture or urban, rarely both. We present differences in dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) molecular composition within Upper Mississippi River Basin low order streams and rivers draining one of three dominant landcovers (forest, agriculture, and urban). Streams draining forest and urban landcovers have greater DOC concentrations, likely driven by differences in carbon sourcing, microbial processing, and soil disturbance. Using Fourier transform-ion cyclotron resonance mass spectrometry, 24% of assigned molecular formulae are common across all landcovers. Relative abundances of N-,S- heteroatomic formulae (CHON, CHOS, CHONS) are higher for agricultural and urban streams, with agricultural stream DOM having more N-containing formulae compared to urban stream DOM, which has more S-containing formulae. Higher N-,S- heteroatomic formulae abundance, along with enrichment in aliphatic, N-aliphatic, and highly unsaturated and phenolic (low O/C) compound categories within agricultural and urban stream DOM are likely to result from increased anthropogenic inputs, autochthonous production, and microbial processing associated with agricultural and urban impacts. Reduced N-,S- heteroatomic formulae abundances in forested stream DOM, along with enrichments in condensed aromatics, polyphenolics, and highly unsaturated phenolic (high O/C) compound categories, likely reflect greater contributions from surrounding organic-rich forest soil and vegetation. Overall, landcover change from forested to agriculture lowers DOC concentrations and changes from forested to agriculture or urban increases autochthonous, and presumably more biolabile, DOM contributions with ramifications for stream biogeochemical cycling.
Released October 06, 2021 17:39 EST
2021, Open-File Report 2021-1086
Jordan L. Wilson, Edward G. Dobrowolski
Autonomous underwater vehicles are uniquely designed to provide spatially dense water-quality data along with bathymetry and velocimetry. The U.S. Environmental Protection Agency Region 5 requested technical assistance from the U.S. Geological Survey in support of ongoing investigations at the Chemical Recovery Systems site to collect spatially dense water-quality and bathymetry data in the East Branch Black River in Elyria, Ohio. This report was prepared in cooperation with the U.S. Environmental Protection Agency to present the results of the autonomous underwater vehicle survey near the Chemical Recovery Systems site on March 22, 2021. Plots of distributions of water temperature, specific conductance, pH, and dissolved oxygen are presented that may help guide and focus future U.S. Environmental Protection Agency efforts at the site to determine the degree of groundwater/surface-water interaction.
Geologic map of the Athabasca Valles region, Mars
Released October 06, 2021 14:36 EST
2021, Scientific Investigations Map 3477
Laszlo P. Keszthelyi, Alexandra E. Huff, Windy L. Jaeger
This 1:1,000,000-scale geologic map of the Athabasca Valles region of Mars places the best-preserved lavas on Mars into their geologic context. The map shows vigorous geologic activity in the most recent epoch of the geologic history of Mars, which is extremely unusual for the planet. In these atypically youthful terrains, the interpretations of geologic processes are exceptionally robust for planetary geologic mapping. The investigation relies heavily on images from the NASA Mars Reconnaissance Orbiter (MRO) High-Resolution Imaging Science Experiment (HiRISE) and Context (CTX) cameras, which have sub-meter and sub-decameter spatial resolution, respectively. Geospatial fidelity is provided by the photogrammetrically controlled 100-meter-per-pixel map base derived from Thermal Emission Imaging System (THEMIS) daytime infrared image data. The individual HiRISE and CTX images are available through the National Aeronautics and Space Administration (NASA) Planetary Data System Cartography and Imaging Sciences Node (https://pds-imaging.jpl.nasa.gov/).
A riverscape approach reveals downstream propagation of stream thermal responses to riparian thinning at multiple scales
Released October 06, 2021 10:56 EST
2021, Ecosphere (12)
David A. Roon, Jason B. Dunham, Christian E. Torgersen
Hydrological connectivity in river networks influences their response to environmental changes as local effects may extend downstream via flowing water. For example, localized changes in riparian forest conditions can affect stream temperatures, and these effects may propagate downstream. However, studies evaluating stream temperature responses to riparian forest management have not considered cumulative effects across entire watersheds. Improved understanding at these scales is needed because land managers are increasingly required to consider broad-scale consequences of their actions. To address this question, we deployed a high-density network of sensors across watersheds to examine stream temperature responses to experimental thinning of riparian forests. A riverscape approach that combined high-resolution data throughout the study watersheds made it possible to examine local and downstream patterns of stream temperature at multiple spatial and temporal scales. We found that local responses of temperature to thinning varied widely depending on the intensity of thinning treatments. Downstream propagation of local responses extended from 100 m to over 1000 m and depended on the magnitude of the local response. We characterized these responses as a series of waveforms. In the watersheds with more intensive thinning, thermal responses occurred most often as an extended pulse where downstream increases in temperature attenuated gradually at variable distances. Although we observed no evidence of cumulative effects associated with thinning at the downstream extent of stream networks, effects emerged where thinning treatments were closely spaced (<400 m apart) and local warming did not dissipate with downstream distance. In a watershed with less intensive thinning, there was either no response or a localized pulse with no downstream propagation. Collectively, these patterns suggest that riparian forest thinning influenced downstream thermal conditions to varying extents depending on the intensity, scale, and spatial proximity of treatments. We found that a multiscale riverscape approach and conceptual framework based on contrasting waveforms provided a foundation for understanding the cumulative watershed effects of riparian thinning. The approach developed here can be adapted more broadly when evaluating downstream propagation of local changes in river networks and has direct implications for guiding restoration in riparian ecosystems.
Exposure to Deepwater Horizon crude oil increases free cholesterol in larval red drum (Sciaenops ocellatus)
Released October 06, 2021 07:49 EST
2021, Aquatic Toxicology
Victoria McGruer, Alexis J. Khursigara, Jason T. Magnuson, Andrew J. Esbaugh, Justin Blaine Greer, Daniel Schlenk
A global ecological classification of coastal segment units to complement marine biodiversity observation network assessments
Released October 06, 2021 07:22 EST
2021, Oceanography (34)
Roger Sayre, Kevin Butler, Keith Van Graafeiland, Sean Breyer, Dawn Wright, Charlie Frye, Deniz Karagulle, Madeline T. Martin, Jill Janene Cress, Tom Allen, Rebecca Allee, Rost Parsons, Bjorn Nyberg, Mark Costello, Peter Harris, Frank Muller-Karger
A new data layer provides Coastal and Marine Ecological Classification Standard (CMECS) labels for global coastal segments at 1 km or shorter resolution. These characteristics are summarized for six US Marine Biodiversity Observation Network (MBON) sites and one MBON Pole to Pole of the Americas site in Argentina. The global coastlines CMECS classifications were produced from a partitioning of a 30 m Landsat-derived shoreline vector that was segmented into 4 million 1 km or shorter segments. Each segment was attributed with values from 10 variables that represent the ecological settings in which the coastline occurs, including properties of the adjacent water, adjacent land, and coastline itself. The 4 million segments were classified into 81,000 coastal segment units (CSUs) as unique combinations of variable classes. We summarize the process to develop the CSUs and derive summary descriptions for the seven MBON case study sites. We discuss the intended application of the new CSU data for research and management in coastal areas.
Vertical movement of soluble carbon and nutrients from biocrusts to subsurface mineral soils
Released October 06, 2021 07:19 EST
2022, Geoderma (405)
Kristina E. Young, Scott Ferrenberg, Robin H. Reibold, Sasha Reed, Tami Swenson, Trent Northen, Anthony Darrouzet-Nardi
Cimarron River alluvial aquifer hydrogeologic framework, water budget, and implications for future water availability in the Pawnee Nation Tribal jurisdictional area, Payne County, Oklahoma, 2016–18
Released October 05, 2021 16:57 EST
2021, Scientific Investigations Report 2021-5073
Nicole C. Paizis, Adam R. Trevisan
The Cimarron River is a free-flowing river and is a major source of water as it flows across Oklahoma. Increased demand for water resources within the Cimarron River alluvial aquifer in north-central Oklahoma (primarily in Payne County) has led to increases in groundwater withdrawals for agriculture, public, irrigation, industrial, and domestic supply purposes. The Pawnee Nation of Oklahoma (Pawnee Nation) is particularly concerned about the sustainability of the Cimarron River alluvial aquifer and whether the aquifer will continue to be a viable water resource for future generations of Tribal members and residents. To better understand current (2021) water resources and possible future water availability in the Pawnee Nation Tribal jurisdictional area, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs and the Pawnee Nation of Oklahoma, compiled available hydrogeologic data and developed conceptual and numerical groundwater-flow models for the Cimarron River alluvial aquifer in Payne County, north-central Oklahoma, including a focus area in the Pawnee Nation Tribal jurisdictional area for the 2016–18 study period.
A conceptual water budget was created to establish estimates of groundwater fluxes into and out of the aquifer through hydrologic boundaries and groundwater withdrawals for use in the numerical groundwater-flow model. The conceptual water budget focuses on the alluvial aquifer, meaning that inflows include sources of water to the aquifer and that outflows include sources of water out of the aquifer, such as base-flow contributions to the Cimarron River. The conceptual water budget was constructed by using data from 2017 (the most complete year of record for each data type included in the model) for the Pawnee Nation subdomain of the Cimarron River alluvial aquifer model extent (Pawnee Nation subdomain).
Groundwater withdrawals were estimated from groundwater-withdrawal rate information for permanent and temporary permitted wells that was obtained from the Oklahoma Water Resources Board. One-half of each annual permitted groundwater-withdrawal rate allotted was used as the estimated annual groundwater-withdrawal amount. Halving the permitted groundwater-withdrawal rate was done because permitted withdrawal rates are the maximum permitted rate and actual groundwater withdrawals are generally appreciably lower than the maximum permitted rate. Total groundwater withdrawals were estimated as 1,300 acre-feet per year for the Pawnee Nation subdomain. Various hydrogeologic data were measured to assist with model development, including depth to bedrock and water-table altitude data. In support of the model development, analyses pertaining to groundwater flow, groundwater/surface-water interactions, base flows in the Cimarron River, and lithological interpretations in the Pawnee Nation Tribal jurisdictional area were used to compute a conceptual water budget applicable to the 2016–18 study period. A numerical groundwater-flow model was developed using the hydrogeologic framework of the Cimarron River alluvial aquifer and the conceptual water budget. The numerical model consists of a single layer representing alluvium and terrace deposits within the alluvial aquifer model area. Hydraulic conductivities were estimated and modeled for the alluvium and terrace deposits in the alluvial aquifer. Base-flow values were estimated using the base-flow index from streamflow data collected at U.S. Geological Survey streamgages. Stream seepage values were derived from the mean 2017 base-flow index between certain streamgages. Hydraulic conductivities were specified an initial (before calibration) value of 120 feet per day for the alluvium deposits and 16 feet per day for the terrace deposits.
The simulated inflows in the numerical groundwater-flow model of the Pawnee Nation subdomain were higher than the inflows of conceptual water budget, and the simulated outflows were lower than the outflows of the conceptual water budget. Overall, simulated base flows matched closely to observed base flows for the 2016 and 2017 stress periods. Simulated streamflow tended to match better with the observed streamflow for 2017, which was the period with the most data for the Cimarron River alluvial aquifer model.
Streamflow capture analysis was applied to the steady-state simulation to identify areas of the aquifer where base flows in the Cimarron River were most sensitive to groundwater withdrawals. The initial base-flow value was assigned the value obtained from streamflow-routing software used to simulate stream outflow for the calibrated steady-state base model. Subsequent simulations were run in each active cell in the Pawnee Nation subdomain for a specified groundwater-withdrawal rate of 180,000 cubic feet per day. The study area that includes the Pawnee Nation subdomain is in the upper Arkansas River Basin. A groundwater-withdrawal rate of 180,000 cubic feet per second per day represents a 34 percent increase compared to the highest permitted groundwater-withdrawal rate for the study area, which corresponds to the estimated 34 percent increase in groundwater withdrawals predicted by 2060 for the upper Arkansas River Basin. Simulated streamflow capture was highest in the alluvium deposits adjacent to the Cimarron River; that is, base flow in the Cimarron River decreased the most for simulated groundwater withdrawals in the alluvium deposits adjacent to the Cimarron River. Streamflow capture increased as the distance of a well from the Cimarron River decreased in the simulation. The northeastern part of the Pawnee Nation subdomain showed greater streamflow capture in a broader area; streamflow in that part of the Pawnee Nation subdomain is likely more sensitive to groundwater withdrawals compared to other parts of the Pawnee Nation subdomain.
Hydrologic and ecological investigations in the School Branch watershed, Hendricks County, Indiana—Water years 2016–2018
Released October 05, 2021 15:00 EST
2021, Scientific Investigations Report 2021-5061
Aubrey R. Bunch, Dawn R. McCausland, E. Randall Bayless
School Branch in Hendricks County in central Indiana, is a small stream with a variety of agricultural and suburban land uses that drains into the Eagle Creek Reservoir, a major source of drinking water for Indianapolis, Indiana. The School Branch watershed has become the focus of a collaborative partnership of Federal, State, and local agencies; a university research center; and agricultural producers to understand the effects of land use and management practices on water quality and water quantity in the watershed. The U.S. Geological Survey, in cooperation with the Indiana Department of Environmental Management, contributed to the School Branch partnership with the operation of three streamgages (03353415 School Branch at Maloney Road near Brownsburg, Indiana; 03353420 School Branch at County Road 750 North at Brownsburg, Indiana; and 03353430 School Branch at Noble Drive at Brownsburg, Indiana) and the operation of a continuous water-quality gage (also known as a supergage) at County Road 750 North that measured dissolved oxygen, pH, temperature, specific conductance, turbidity, nitrate, and orthophosphate. Additional efforts included the use of passive samplers to identify wastewater indicators; assessment of fish and macroinvertebrate communities and stream habitat to identify ecological impairment; sampling for nutrients and sediment to estimate loads; and using major ions, stable isotopes and nested groundwater monitoring wells at County Road 750 North to determine hydrologic connectivity between the groundwater and surface water. The objectives of this study were to collect surface and groundwater data to analyze the hydrology and water quality within the watershed. Total nitrogen yields were highest at the upstream site, Maloney Road, and indicated a mixture of nitrogen sources in the watershed. Differences found in total nitrogen loading patterns throughout the watershed may be linked to differences in hydrology and land-use management from site to site. The groundwater and surface water were shown to be highly connected, and except for some low-flow periods, the water was flowing from groundwater to the stream for most of the study period. Fish and macroinvertebrate communities show improvement from upstream to downstream, with increases in diversity, richness, and species sensitive to poor water quality and habitat. These increases were most likely due to improved habitat quality at the downstream station.
Five-year management plan for establishing and operating NVEWS—The National Volcano Early Warning System
Released October 05, 2021 14:45 EST
2021, Open-File Report 2021-1092
Peter F. Cervelli, Charles W. Mandeville, Victoria F. Avery, Aleeza M. Wilkins
On March 12, 2019, Congress passed the John D. Dingell, Jr., Conservation, Management, and Recreation Act (Public Law 116–9; 133 Stat. 580), in which Title V, §5001 (43 U.S.C. 31k) authorized the establishment of the National Volcano Early Warning and Monitoring System (NVEWS) within the U.S. Geological Survey (USGS). Conceived by the USGS Volcano Hazards Program in 2005, NVEWS is designed to be a proactive, fully integrated national-scale volcano monitoring system to ensure that the 161 potentially active volcanoes in the United States and its territories are monitored at levels commensurate with the threat they pose. The core of this report is the first USGS NVEWS five-year management plan, which was presented to Congress on March 12, 2020, and which details the principal elements of NVEWS that will be developed over the next five years, pending sufficient funding. These elements are improvements and enhancements to the monitoring network, a National Volcano Data Center, an external grants activity, an Advisory Committee, an Implementation Committee, and partnerships, with estimated cost projections and annual milestones.
Simulated atmospheric response to four projected land-use land-cover change scenarios for 2050 in the north-central United States
Released October 05, 2021 07:26 EST
2021, Earth Interactions (25) 177-194
Paul Xavier Flanagan, Rezaul Mahmood, Terry L. Sohl, Mark Svoboda, Brian D. Wardlow, Michael Hayes, Eric Rappin
Iñupiaq knowledge of polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska
Released October 05, 2021 06:36 EST
2021, Arctic (74) 239-257
Karyn D. Rode, Hannah Voorhees, Henry P. Huntington, George M. Durner
High-speed lava flow infrasound from Kīlauea’s fissure 8 and its utility in monitoring effusion rate
Successful wildlife management depends upon coordination and consultation with local communities. However, much of the research used to inform management is often derived solely from data collected directly from wildlife. Indigenous people living in the Arctic have a close connection to their environment, which provides unique opportunities to observe their environment and the ecology of Arctic species. Further, most northern Arctic communities occur within the range of polar bears (nanuq, Ursus maritimus) and have experienced significant climatic changes. Here, we used semi-structured interviews from 2017 to 2019 to document Iñupiaq knowledge of polar bears observed over four decades in four Alaskan communities in the range of the Southern Beaufort Sea polar bear subpopulation: Wainwright, Utqiaġvik, Nuiqsut, and Kaktovik. All but one of 47 participants described directional and notable changes in sea ice, including earlier ice breakup, later ice return, thinner ice, and less multiyear pack ice. These changes corresponded with observations of bears spending more time on land during the late summer and early fall in recent decades—observations consistent with scientific and Indigenous knowledge studies in Alaska, Canada, and Greenland. Participants noted that polar bear and seal body condition and local abundance either varied geographically or exhibited no patterns. However, participants described a recent phenomenon of bears being exhausted and lethargic when arriving on shore in the summer and fall after extensive swims from the pack ice. Further, several participants suggested that maternal denning is occurring more often on land than sea ice. Participants indicated that village and regional governments are increasingly challenged to obtain resources needed to keep their communities safe as polar bears spend more time on land, an issue that is likely to be exacerbated both in this region and elsewhere as sea ice loss continues.
Released October 05, 2021 05:52 EST
2021, Bulletin of Volcanology (83)
John J. Lyons, Hannah R. Dietterich, Matthew R. Patrick, David Fee
Complex vulnerabilities of the water and aquatic carbon cycles to permafrost thaw
The 2018 eruption of Kīlauea Volcano produced large and destructive lava flows from the fissure 8 (Ahu ‘aila ‘au) vent with flow velocities up to 17 m s−1, highly variable effusion rates over both short (minutes) and long (hours) time scales, and a proximal channel or spillway that displayed flow features similar to open channel flow in river systems. Monitoring such dynamic vent and lava flow systems is a challenge. Our results demonstrate that infrasound, combined with ground-based observations and imagery from unoccupied aircraft systems (UAS), can be used to distinguish vent degassing activity from high-speed lava flow activity. We use spectral characteristics and the infrasound frequency index (FI) to distinguish spillway infrasound from vent infrasound. Comparing FI with flow speeds derived from UAS videos reveals that spillway infrasound only occurs when flow speeds were sufficiently high to cause a supercritical flow state and breaking waves (Froude values > 1.7), and we propose that the spillway signals are produced primarily through the interaction of the turbulent lava-free surface with the atmosphere. We show that FI can also provide a means to track bulk effusion rate. Our results indicate that infrasound offers a new way to characterize lava flow channel hydraulics and is a powerful tool for monitoring effusive eruptions when high-speed flows are possible.
Released October 04, 2021 16:37 EST
2021, Frontiers in Climate (3)
Michelle A. Walvoord, Robert G. Striegl
The spatial distribution and depth of permafrost are changing in response to warming and landscape disturbance across northern Arctic and boreal regions. This alters the infiltration, flow, surface and subsurface distribution, and hydrologic connectivity of inland waters. Such changes in the water cycle consequently alter the source, transport, and biogeochemical cycling of aquatic carbon (C), its role in the production and emission of greenhouse gases, and C delivery to inland waters and the Arctic Ocean. Responses to permafrost thaw across heterogeneous boreal landscapes will be neither spatially uniform nor synchronous, thus giving rise to expressions of low to medium confidence in predicting hydrologic and aquatic C response despite very high confidence in projections of widespread near-surface permafrost disappearance as described in the 2019 Intergovernmental Panel on Climate Change Special Report on the Ocean and Cryosphere in a Changing Climate: Polar Regions. Here, we describe the state of the science regarding mechanisms and factors that influence aquatic C and hydrologic responses to permafrost thaw. Through synthesis of recent topical field and modeling studies and evaluation of influential landscape characteristics, we present a framework for assessing vulnerabilities of northern permafrost landscapes to specific modes of thaw affecting local to regional hydrology and aquatic C biogeochemistry and transport. Lastly, we discuss scaling challenges relevant to model prediction of these impacts in heterogeneous permafrost landscapes.
Vulnerability assessment in and near Theodore Roosevelt National Park, North Dakota
Released October 04, 2021 14:44 EST
2021, Scientific Investigations Map 3479
Kristen J. Valseth
Theodore Roosevelt National Park is in western North Dakota and was established in 1978 under the National Wilderness Preservation system to preserve and protect the qualities of the North Dakota Badlands, including the wildlife, scenery, and wilderness. The park is made up of three units (North, Elkhorn Ranch, and South) that are connected by the Little Missouri River, which was identified by the National Park Service as a significant resource essential to fulfilling the park's purpose. The development of oil and gas (OG) resources has expanded in the past two decades in the region surrounding Theodore Roosevelt National Park. This expansion of OG development outside park boundaries increases the potential for adverse environmental and economic effects inside the park boundaries, especially for the hydrologic processes within Theodore Roosevelt National Park.
This report assesses the vulnerability of critical components that contribute to supporting plants and wildlife of the Northwestern Great Plains ecological region and Theodore Roosevelt National Park’s mission of preservation. Critical components include land cover, slope, soil saturated hydraulic conductivity, distance to Ovis canadensis (Shaw, 1804) (bighorn sheep) critical habitat, distance to springs, distance to rivers and streams, and distance to surficial aquifers. The study area included all the 12-digit hydrologic units within the watershed boundary dataset that intersect Theodore Roosevelt National Park or are within the 12-digit hydrologic units for Little Missouri River tributaries that flow into the park. Critical components that had existing publicly available geographic data were assessed and assigned vulnerability index values. These values were then summed to develop a vulnerability score and mapped. OG development and associated transportation infrastructure, referred to as “stressors” in this report, with publicly available geographic data were mapped, and then flow paths were generated starting from the stressor locations to assess their likelihood to contaminate vulnerable areas within the study area.
The North Unit had the most area with moderate, high, and very high vulnerability. These areas occurred all across the southern and eastern parts of the North Unit where the Little Missouri River, surficial aquifer, wetland type land covers, and bighorn sheep critical habitat are present. Several stressor flow paths from pipelines and highways cross these areas and may pose the most risk to the vulnerable areas identified. In the Elkhorn Ranch Unit, areas with moderate, high, and very high vulnerability were in the southeastern part of the unit, where the Little Missouri River, surficial aquifer, wetland type land covers, and bighorn sheep critical habitat are present. The stressor flow paths in the Elkhorn Ranch Unit follow the length of the Little Missouri River and all its tributaries in the study area. The stressor flow paths originated from crude oil wells and pipelines. In the South Unit, one area had moderate, high, and very high vulnerability. This area is where the Little Missouri River and bighorn sheep critical range are present. The stressor flow paths in the South Unit follow the length of the Little Missouri River and nearly all its tributaries in the study area. Several stressor flow paths cross the one identified vulnerable area that originated from crude oil wells.
Utilizing multiple hydrogeologic and anthropogenic indicators to understand zones of groundwater contribution to water-supply wells near Kirtland Air Force Base Bulk Fuels Facility in southeast Albuquerque, New Mexico
Released October 04, 2021 13:33 EST
2021, Scientific Investigations Report 2021-5076
Rebecca E. Travis, Meghan T. Bell, Benjamin S. Linhoff, Kimberly R. Beisner
In 1999, a jet-fuels release was discovered at the Bulk Fuels Facility on Kirtland Air Force Base, Albuquerque, New Mexico. Contaminants had reached the water table and migrated north-northeast toward water-supply wells. Monitoring wells were installed downgradient from the facility to determine the primary zones of groundwater production for water-supply wells and assess contaminant presence. The monitoring wells are screened within the Santa Fe Group aquifer system, which includes clay units, at depths as great as 445 meters below land surface, and were categorized as water table, shallow, middle, deep, and aquifer-test pumping wells. Water-supply wells are screened across multiple water-bearing units within the aquifer system. All wells were sampled for major ions, trace elements, nutrients, stable isotopes, dissolved gases, tritium, carbon isotopes, and chlorofluorocarbons. The deeper and water-supply wells have evidence of longer groundwater residence times, as much as thousands of years, and water from the shallower wells shows evidence of anthropogenic nutrient inputs. Aquifer recharge is derived from either the mountain front or seepage from the Rio Grande. Dissolved-gas data indicate that the middle, deep, and aquifer-test pumping, and water-supply wells have cooler recharge temperatures than the shallower wells. Inferred groundwater age varies by method but indicates that the deeper, aquifer-test pumping, and water-supply wells have older water, as much as 15,000 years before present. Results indicate that the water-supply wells draw primarily from the middle and deeper portions of the aquifer system below the clay units and have not been affected by the contaminant plume, although some data indicate a potential for modern water entering some of the deeper and water-supply wells.
Delineation of areas contributing groundwater and travel times to receiving waters in Kings, Queens, Nassau, and Suffolk Counties, New York
Released October 01, 2021 11:00 EST
2021, Scientific Investigations Report 2021-5047
Paul E. Misut, Nicole A. Casamassina, Donald A. Walter
To assist resource managers and planners in developing informed strategies to address nitrogen loading to coastal water bodies of Long Island, New York, the U.S. Geological Survey and New York State Department of Environmental Conservation initiated a program to delineate areas contributing groundwater to coastal water bodies by assembling a comprehensive dataset of areas contributing groundwater, travel times, and groundwater discharges to streams, lakes, marine surface waters, and subsea discharge boundaries. Steady-state, 25-layer regional, three-dimensional finite-difference groundwater-flow models of average regional hydrologic conditions were used for particle-tracking analysis to delineate areas contributing groundwater to 843 water bodies. Two steady-state conditions were simulated: recent conditions from 2005 to 2015 and predevelopment conditions of about 1900. About 14 million particles were evenly distributed across the water table and tracked forward to discharge zones. Using a uniform porosity of 25 percent, simulated recent condition travel times ranged from less than 2 years to greater than 10,000 years and were visualized in 11 travel time intervals. About 85 percent of particle travel times from the water table to points of discharge are less than 100 years. Simulated particle-tracking ending zones represented 843 receiving water bodies, based on the New York State Department of Environmental Conservation water body inventory and priority water bodies list. Areal delineation of travel-time intervals and areas contributing groundwater to water bodies were generated and are summarized with total groundwater outflow for each water body.
Mercury isotope fractionation by internal demethylation and biomineralization reactions in seabirds: Implications for environmental mercury science
Released October 01, 2021 06:57 EST
2021, Environmental Science and Technology
Alain Manceau, Romain Brossier, Sarah E. Janssen, Tylor Rosera, David P. Krabbenhoft, Yves Cherel, Paco Bustamante, Brett Poulin
Conceptual and numerical groundwater flow model of the Cedar River alluvial aquifer system with simulation of drought stress on groundwater availability near Cedar Rapids, Iowa, for 2011 through 2013
A prerequisite for environmental and toxicological applications of mercury (Hg) stable isotopes in wildlife and humans is quantifying the isotopic fractionation of biological reactions. Here, we measured stable Hg isotope values of relevant tissues of giant petrels (Macronectes spp.). Isotopic data were interpreted with published HR-XANES spectroscopic data that document a stepwise transformation of methylmercury (MeHg) to Hg-tetraselenolate (Hg(Sec)4) and mercury selenide (HgSe) (Sec = selenocysteine). By mathematical inversion of isotopic and spectroscopic data, identical δ202Hg values for MeHg (2.69 ± 0.04‰), Hg(Sec)4 (−1.37 ± 0.06‰), and HgSe (0.18 ± 0.02‰) were determined in 23 tissues of eight birds from the Kerguelen Islands and Adélie Land (Antarctica). Isotopic differences in δ202Hg between MeHg and Hg(Sec)4 (−4.1 ± 0.1‰) reflect mass-dependent fractionation from a kinetic isotope effect due to the MeHg → Hg(Sec)4 demethylation reaction. Surprisingly, Hg(Sec)4 and HgSe differed isotopically in δ202Hg (+1.6 ± 0.1‰) and mass-independent anomalies (i.e., changes in Δ199Hg of ≤0.3‰), consistent with equilibrium isotope effects of mass-dependent and nuclear volume fractionation from Hg(Sec)4 → HgSe biomineralization. The invariance of species-specific δ202Hg values across tissues and individual birds reflects the kinetic lability of Hg-ligand bonds and tissue-specific redistribution of MeHg and inorganic Hg, likely as Hg(Sec)4. These observations provide fundamental information necessary to improve the interpretation of stable Hg isotope data and provoke a revisitation of processes governing isotopic fractionation in biota and toxicological risk assessment in wildlife.
Released September 30, 2021 21:14 EST
2021, Scientific Investigations Report 2021-5065
Adel E. Haj, Wonsook S. Ha, Lance R. Gruhn, Emilia L. Bristow, Amy M. Gahala, Joshua F. Valder, Carole D. Johnson, Eric A. White, Shelby P. Sterner
Between July 2011 and February 2013, the City of Cedar Rapids observed water level declines in their horizontal collector wells approaching 11 meters. As a result, pumping from these production wells had to be halted, and questions were raised about the reliability of the alluvial aquifer under future drought conditions. The U.S. Geological Survey, in cooperation with the City of Cedar Rapids, completed a study to better understand the effects of drought stress on the Cedar River alluvial aquifer using a numerical groundwater flow model. Previously published groundwater flow models were combined with newly collected airborne, waterborne, down-hole, and land-based geophysical survey data and provided a detailed three-dimensional lithologic model of the Cedar River alluvial aquifer and surrounding area. An improved conceptual model for the groundwater flow system and a lithologic model were used to build and inform a numerical groundwater flow model capable of simulating water levels observed in the City of Cedar Rapids horizontal collector wells during the 2012 drought. Model performance was assessed primarily on the ability of the model to simulate water table elevation at six monitoring wells. Statistical tests were used to assess the numerical model during the calibration period, and results varied from satisfactory to unsatisfactory, likely because of stage changes in the Cedar River and production well withdrawal rates near monitoring wells. Simulated water levels during the 2012 drought indicated a depression near the horizontal collector wells, although simulated elevations at these locations and at monitoring wells were generally overestimated compared to measured values. The numerical groundwater flow model was modified to account for a decrease in seepage rate caused by low flow in the Cedar River and increased production. With seepage rate modification, model results improved; the simulated water table elevations were like those observed in horizontal collector and monitoring wells. Results demonstrated the ability of the model to simulate water levels observed in the horizontal collector wells during the 2012 drought when accounting for a decrease in infiltration from the Cedar River.
Methods for estimating low-flow frequency statistics, mean monthly and annual flow, and flow-duration curves for ungaged locations in Kansas
Released September 30, 2021 16:14 EST
2021, Scientific Investigations Report 2021-5100
Bradley S. Lukasz
Knowledge of the magnitude, frequency, and duration of low flows is critical for water-supply management; reservoir design; waste-load allocation; and the preservation of water quality and quantity for irrigation, recreation, and ecological conservation purposes. The U.S. Geological Survey (USGS), in cooperation with the Kansas Water Office, completed a statewide study to develop regression equations for selected low-flow frequency and flow-duration statistics for ungaged streams in Kansas.
The low-flow statistics included the annual and monthly 1-, 7-, and 30-day mean low flow for a recurrence interval of 10 years; flow-duration exceedance probabilities of 0.01, 0.1, 2, 5, 10, 25, 50, 75, 90, 95, 99, 99.9, and 99.99 percent; and mean annual flow. Data used in this analysis were from 254 USGS continuous-record streamgages using data through March 31, 2017, for the regression equation analysis and using data through September 30, 2017, for the flow-duration curve analysis. The streamgages used in the regression analysis of this report are in Kansas and 50 miles beyond the borders of the State. A trend analysis was done because trends can introduce bias into results. Some trends were detected; however, no streamgage was omitted from the analysis because of the presence of a trend. Geographic-information-system software was used to compute 13 basin characteristics for each streamgage.
The State of Kansas was divided into two study areas for the regional regression analysis. Logistic and left-censored regression techniques were used to develop the equations because of the presence of zero flows in the datasets. A collection of performance metrics is provided to estimate the accuracy of each equation. These equations are only applicable to streams in Kansas that are not substantially affected by diversion, regulation, or urbanization. Basin characteristics of these ungaged locations also need to be within the range of the basin characteristics used to develop these equations.
The drainage-area ratio (DAR) method was tested against the regional regression equations using 19 pairs of streamgages. The 7-day annual mean low-flow statistic was estimated using the regression equations and the DAR method. The absolute difference, in percent, was calculated using the observed 7-day annual mean low flow for both methods. The results of the Wilcoxon signed-rank test indicated that the difference between the absolute differences, in percent, for the groups tested was not statistically significant. Previous USGS studies state it is preferable to use the DAR method when the ratio is between 0.5 and 1.5. Some studies offer no scientific basis for these guidelines, whereas other studies have developed different guidelines. In Kansas, the DAR method produced the smallest absolute difference, in percent, when the ratio of drainage areas was between 0.5 and 1.5. The results of this study indicate that the DAR method is appropriate for use in Kansas when estimating streamflow at an ungaged location if there is a nearby streamgage on the same river or stream where the DAR is between 0.5 and 1.5 and the low-flow statistic at the nearby streamgage is not zero.
The regression equations developed in this report will be incorporated into the USGS StreamStats web-based geographic-information-system tool. This will allow users to click on any ungaged location within StreamStats and compute estimates of the selected low-flow frequency and flow-duration statistics. The low-flow frequency and flow-duration statistics for streamgages in Kansas also will be available in StreamStats.
Hydrogeologic framework, water levels, and selected contaminant concentrations at Valmont TCE Superfund Site, Luzerne County, Pennsylvania, 2020
Released September 30, 2021 13:15 EST
2021, Open-File Report 2021-1093
Lisa A. Senior, Alex R. Fiore, Philip H. Bird
The Valmont TCE Superfund Site, Luzerne County, Pennsylvania is underlain by fractured and folded sandstones and shales of the Pottsville and Mauch Chunk Formations, which form a fractured-rock aquifer recharged locally by precipitation. Industrial activities at the former Chromatex Plant resulted in trichloroethene (TCE) contamination of groundwater at and near the facility, which was identified in 1987 and led to listing as a Superfund site by the U.S. Environmental Protection Agency (EPA) in 1989. To address the problem of TCE concentrations in nearby residential wells that exceed the maximum contaminant level (MCL) of 5 micrograms per liter (μg/L), alternate water supplies were provided. A 2015 review of initial characterization and subsequent remediation by the EPA identified the need for an updated understanding of the complex hydrogeology and the conceptual site model. Additional contaminants present in groundwater at the site include some other volatile organic compounds (VOCs) and per- and polyfluoroalkyl substances (PFAS), predominantly consisting of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) present in concentrations that exceeded the EPA Health Advisory (HA) level of 5 nanograms per liter (ng/L) for combined PFOA and PFOS.
In response to a request from the EPA in 2019, the U.S. Geological Survey (USGS) prepared cross sections and maps to provide more information about the hydrogeologic framework at and near the site and assist in improving the conceptual site model using water level and contaminant data collected by the EPA in 2020. The cross sections present lithologic correlations from available geophysical logs collected in wells from 2002 to 2014; they show alternating intervals of relatively elevated and reduced natural gamma activity that correspond to changes in lithology, with water-bearing zones and well screens commonly located at lithologic contacts, sometimes near thin coal seams. Water-bearing zones commonly are associated with fractures at or near lithologic contacts but also may be associated with fractures at or near apparent faulting. Recent (March 2020) water-level data shown on cross sections and maps indicate large downward vertical gradients and apparent radial gradients laterally to the northeast, northwest, and southwest that generally following topography. Recent (February to March 2020) data for TCE groundwater concentration shown on cross sections and maps indicate the highest TCE concentrations (greater than 3,000 μg/L and as much as 75,000 μg/L) and combined PFOA and PFOS concentrations (greater than 1,000 ng/L and up to at least 2,350 ng/L) are from shallow (less than 60 feet [ft] below land surface [bls]) and intermediate depth (60 to 100 ft bls) wells near the center of the former Chromatex Plant. TCE and PFAS (as combined PFOA and PFOS) contamination is present at greater depths, as much as 304 ft bls, as evidenced by samples collected from one well (a reconstructed former production well) near the plant, that contained concentrations of about 240 μg/L and 508 ng/L, respectively. The 2020 data also indicate that TCE and PFAS concentrations which exceed drinking-water MCL or HA levels are present in groundwater depths of less than 200 ft in an area that extends predominantly in a northeast direction from the former Chromatex Plant, and is apparently influenced by hydraulic gradients, lithology, and geologic structure.
Technical note—Relative variability of selected turbidity standards and sensors in use by the U.S. Geological Survey
Released September 30, 2021 12:30 EST
2021, Open-File Report 2021-1009
Guy M. Foster, Lindsey R. King, John D. Jastram, John K. Joiner, Brian A. Pellerin, Jennifer L. Graham, Thomas J. Williams
The challenges associated with field measurements of turbidity are well known and result primarily from differences in reported values that depend on instrument design and the resulting need for reporting units that are specific to those designs. A critical challenge for making comparable turbidity measurements is the selection and use of appropriate turbidity standards for sensor calibration. The accepted primary standards for turbidity measurements use formazin made from scratch; all others should relate back to readings obtained using standard formazin. However, because turbidity is a qualitative property of water, comparing standards is not as simple as it is for many chemical measurements. The U.S. Geological Survey “National Field Manual for the Collection of Water-Quality Data” currently allows for the use of two standards, formazin and polymer beads, for the calibration of field turbidimeters. Another challenge for making comparable turbidity measurements is selection of turbidity sensors. A turbidity sensor commonly used in the U.S. Geological Survey, the Yellow Springs Instruments (YSI) 6136, has been replaced by the manufacturer with the YSI EXO turbidity sensor. Both sensors operate on the same principles but have slight design differences that result in readings that are not directly comparable on a 1:1 basis.
Differences in calibration standards and sensors are a cause of concern in ongoing studies that require switching calibration standards or sensor types, and for comparisons of data collected with sensors calibrated by using different calibration standards, different sensor types, or both. The objectives of this study were to evaluate the response of two YSI turbidity sensors in both formazin-based standards (StablCal) and polymer turbidity standards (in this case YSI brand; however, other brands are available) and to compare the performance of the YSI EXO and YSI 6136 turbidity sensors under similar laboratory and environmental (field) conditions. To quantify these differences, a series of laboratory and field side-by-side comparisons were conducted. Nine field comparisons of YSI EXO and YSI 6136 sensors were performed at site locations in Kansas and Virginia. Two field comparisons of StablCal and polymer calibration standards were performed in Kansas, both using YSI EXO turbidity sensors. Five laboratory comparisons between the YSI EXO and YSI 6136 turbidity sensors were performed, and seven laboratory comparisons between StablCal and polymer turbidity standards were performed using YSI EXO turbidity sensors. The results can help the USGS and others better understand how turbidity data can differ depending on the sensors and calibration standards used.
Key findings and conclusions include the following—
U.S. Geological Survey Great Lakes Science Forum—Summary of remaining data and science needs and next steps
- Regardless of the comparison, strong linear associations were typically found across all measures of turbidity under field and laboratory conditions, but linear associations were not necessarily 1:1 and varied by type of standard, type of sensor, and field and laboratory conditions.
- The mean relative percentage differences for all but a few comparisons were greater than 10 percent but less than 30 percent. However, differences were inconsistent across the laboratory and field conditions measured in this study, precluding the ability to formulate definitive statements of consistent directional bias depending on the type of standard or sensor used.
- Across all tests and a range of 0 to 1,000 formazin nephelometric units (FNU), no consistent bias between the YSI EXO and YSI 6136 turbidity sensors was observed, but either regression relations were near 1:1 or the YSI EXO turbidity readings were lower than those measured with the YSI 6136. Relative percentage differences typically exceeded the 10- and 30-percent benchmarks. However, most (about 95 percent) of the absolute differences between turbidity values measured with the YSI EXO and those measured with the YSI 6136 sensors were less than 20 FNU.
- In laboratory experiments, when turbidity was “constant,” the absolute difference between YSI EXO and YSI 6136-measured turbidity values ranged from near 0 FNU to nearly 400 FNU (over a range of 0 to 1,000 FNU). Substantial variability in turbidity measurements makes comparison between standards and sensor types challenging.
- Given the inherent variability in turbidity measurements and the lack of consistent bias between calibration standards or sensors, changing methods during an ongoing study would compromise the comparability of the data. The effect of changing methods ultimately depends on study objectives. If method changes are required, laboratory- and field-based comparisons across a range of conditions ideally would be conducted to determine whether site-specific biases can be identified.
Released September 30, 2021 12:11 EST
2021, Open-File Report 2021-1096
Leon M. Carl, Jon E. Hortness, Russell M. Strach
A U.S. Geological Survey-led assessment of data gaps and science needs across the Great Lakes ecosystem indicated the following:
• Expanded data collection or monitoring would provide basic ecosystem, social, and public health data to manage the Great Lakes system and to develop and test models and decision support tools.
• New science and advanced technologies (for example, sensors and high-performance computing capability) would improve the understanding of critical threats, such as harmful algae blooms and high-water levels.
Although there is significant scientific knowledge in specific areas or for specific topics, managers could use improved models and decision support tools, strengthened by extensive data collection and developed at multiple scales, to better inform decision making in the future. Enhanced coordination of agency efforts and associated data collection across data types (for example, prey fish populations and water levels) is needed to effectively manage the Great Lakes.
This report highlights the data gaps; benefits of better, more structured coordination; and areas of concern specifically related to data collection/measurement and science efforts. It summarizes and analyzes stakeholder feedback and information from review of scientific literature. Finally, the report outlines steps necessary to create an integrated Great Lakes science plan.
Machine learning can assign geologic basin to produced water samples using major ion geochemistry
Released September 30, 2021 08:16 EST
2021, Natural Resources Research
Jenna L. Shelton, Aaron M. Jubb, Samuel Saxe, Emil D. Attanasi, Alexei Milkov, Mark A Engle, Philip A. Freeman, Christopher Shaffer, Madalyn S. Blondes
Understanding the geochemistry of waters produced during petroleum extraction is essential to informing the best treatment and reuse options, which can potentially be optimized for a given geologic basin. Here, we used the US Geological Survey’s National Produced Waters Geochemical Database (PWGD) to determine if major ion chemistry could be used to classify accurately a produced water sample to a given geologic basin based on similarities to a given training dataset. Two datasets were derived from the PWGD: one with seven features but more samples (PWGD7), and another with nine features but fewer samples (PWGD9). The seven-feature dataset, prior to randomly generating a training and testing (i.e., validation) dataset, had 58,541 samples, 20 basins, and was classified based on total dissolved solids (TDS), bicarbonate (HCO3), Ca, Na, Cl, Mg, and sulfate (SO4). The nine-feature dataset, prior to randomly splitting into a training and testing (i.e., validation) dataset, contained 33,271 samples, 19 basins, and was classified based on TDS, HCO3, Ca, Na, Cl, Mg, SO4, pH, and specific gravity. Three supervised machine learning algorithms—Random Forest, k-Nearest Neighbors, and Naïve Bayes—were used to develop multi-class classification models to predict a basin of origin for produced waters using major ion chemistry. After training, the models were tested on three different datasets: Validation7, Validation9, and one based on data absent from the PWGD. Prediction accuracies across the models ranged from 23.5 to 73.5% when tested on the two PWGD-based datasets. A model using the Random Forest algorithm predicted most accurately compared to all other models tested. The models generally predicted basin of origin more accurately on the PWGD7-based dataset than on the PWGD9-based dataset. An additional dataset, which contained data not in the PWGD, was used to test the most accurate model; results suggest that some basins may lack geochemical diversity or may not be well described, while others may be geochemically diverse or are well described. A compelling result of this work is that a produced water basin of origin can be determined using major ions alone and, therefore, deep basinal fluid compositions may not be as variable within a given basin as previously thought. Applications include predicting the geochemistry of produced fluid prior to drilling at different intervals and assigning historical produced water data to a producing basin.
Avian predation of juvenile Lost River and Shortnose Suckers in Upper Klamath Lake: An assessment of Sucker assisted rearing program releases during 2018–2020
Released September 30, 2021 06:50 EST
Allen Evans, Quinn Payton, Nathan V Banet, Bradley M. Cramer, Caylen Kelsey, David A. Hewitt
To bolster recruitment in Endangered Species Act (ESA) listed Lost River Suckers (Deltistes luxatus) and Shortnose Suckers (Chasmistes brevirostris) in the Upper Klamath Basin (UKB), the U.S. Fish and Wildlife Service (USFWS) and its partners have implemented the Sucker Assisted Rearing Program (SARP). As part of this program, juvenile suckers were reared in captivity, implanted with passive integrated transponder (PIT) tags (n= 8,857), and released into the Upper Klamath Lake or its tributaries during 2018–2020. Previous research suggests that predation by American White Pelicans (Pelecanus erythrorhynchos), Double-crested Cormorants (Nannopterum auritum), and Caspian Terns (Hydroprogne caspia) may negatively influence sucker survival, particularly predation on juvenile suckers. Estimates of predation impacts from past studies, however, represented minimum estimates of sucker mortality because analyses did not account for the proportion of consumed tags that were deposited by birds on their breeding colony where PIT tag recovery efforts took place. To estimate and account for deposition probabilities, we conducted a field study in which we fed pelicans PIT-tagged juvenile suckers (n = 401). We accounted for deposition probabilities of cormorants and terns by using previously published estimates. Sucker PIT tags were recovered from pelican, cormorant, and tern nesting sites in the UKB following each breeding season and a hierarchical Bayesian model was used to estimate predation rates (percentage of available tagged fish consumed) on SARP releases as well as naturally-reared or wild juvenile suckers and adult suckers that were PIT-tagged in Upper Klamath Lake and Clear Lake Reservoir. Pelican deposition probabilities were estimated at 0.47 (95% credible interval = 0.36–0.60), indicating that for every 100 PIT tags consumed, on average, 47 were deposited by pelicans on breeding colonies. Estimates of predation rates that incorporate corrections for deposition on SARP releases ranged annually from 4.4% (95% credible interval = 2.9–6.8%) to 8.8% (6.2–13.3%) during 2018–2020. Results suggest that colonial waterbird predation impacts on SARP releases likely constituted a small, but unknown, component of total mortality for suckers released into the Upper Klamath Lake system. Predation impacts on SARP juvenile suckers and wild juvenile suckers, which were estimated annually at 4.7% (1.0–13.9%) to 14.9% (7.6–29.3%), were consistently higher than those observed on adult suckers, with predation on adult suckers typically less than 4.0% of available fish annually. Future predation studies may consider models that integrate both live and dead detections of PIT-tagged suckers to generate more accurate and precise estimates of survival following release, as well as models that consider environmental factors that influence sucker susceptibility to colonial waterbird predation. Such models would provide a more holistic understanding of the degree to which avian predation limits the survival of ESA-listed suckers in the UKB.
Characterization of water resources in the Big Lost River Basin, south-central Idaho
Released September 29, 2021 13:41 EST
2021, Scientific Investigations Report 2021-5078
Lauren M. Zinsser, editor(s)
Water resources in the Big Lost River Basin, Idaho are vital to irrigated agriculture, domestic, municipal and other uses but declining groundwater levels, diminished streamflows, and concern about drought motivated an evaluation of water resources in the basin. This multichapter volume documents the findings of a hydrogeologic investigation of the Big Lost River Basin that was jointly conducted by the U.S. Geological Survey, Idaho Department of Water Resources, and Idaho Geological Survey from 2018 through 2021. Chapter A (Zinsser, 2021) describes the hydrogeologic framework of the Big Lost River Basin. The framework presents a conceptual definition of four hydrogeologic units, a three-dimensional hydrogeologic framework model representing the spatial occurrence of the hydrogeologic units, and a description of groundwater occurrence and movement. Chapter B (Dudunake and Zinsser, 2021) describes streamflow gains from and losses to groundwater in the Big Lost River between Mackay Reservoir and south of Arco. Streamflow losses and gains were estimated from a series of four measurement events completed during spring and fall conditions from 2019 to 2021. Chapter C will describe groundwater budgets for the Big Lost River Basin from 2000 to 2019. The groundwater budgets will provide annual estimates for aquifer inflows and outflows and include representations of average, wet, and dry conditions. Collectively, these reports present a characterization of water resources in the Big Lost River Basin that will help address current challenges in water-resources management.
Surface-water and groundwater interactions in the Big Lost River, south-central Idaho
Released September 29, 2021 13:34 EST
2021, Scientific Investigations Report 2021-5078-B
Taylor J. Dudunake, Lauren M. Zinsser
The Big Lost River of south-central Idaho interacts with the underlying aquifer by gaining and losing streamflow throughout various areas in the Big Lost River Valley. Surface-water and groundwater resources are used throughout the valley to sustain domestic, agricultural, and livestock needs. The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources, evaluated streamflow gains and losses by differential streamgaging in the lower Big Lost River, Idaho, during four measurement events: March 27–28, 2019; October 16–17, 2019; October 6–7, 2020; and March 30, 2021. This report presents and analyzes streamflow measurement and uncertainty data from each measurement event to describe surface-water/groundwater interactions. This report is the second chapter of a multi-chapter volume that characterizes water resources in the Big Lost River Basin.
During the four measurement events, 100 streamflow measurements were made at 46 unique sites on the Big Lost River, James Creek, and diversions or tributaries between Mackay Reservoir near Mackay and Arco, Idaho. Aquifer lithology and dimensions affected spatial patterns of streamflow gains and losses between the upper, middle, and lower reaches; changes in water supply, groundwater levels, and surface-water management affected seasonal differences within reaches. In the upper reach of the Big Lost River, streamflow losses and gains were greater during the wetter 2019 events and lesser during the drier 2020 and 2021 events. The middle reach includes the largest losses from the Big Lost River to groundwater; these losses occurred in the Darlington Sinks where 42 percent or more of streamflow was lost as the aquifer widens and groundwater deepens. These results suggest that changing surface-water supply, irrigation use, and recharge affect interannual groundwater levels and, in turn, affect patterns of streamflow gains and losses in the middle reach. Finally, surface-water management is the primary control on surface-water/groundwater interactions in the lower reach. Overall patterns of streamflow gains and losses in this study generally were consistent with previous reports. However, paired with the related hydrogeologic framework and water budget, this investigation provides new insights into how hydrogeologic conditions and interannual variability in water supply, groundwater levels, and surface-water management affect surface-water/groundwater interactions in the Big Lost River Valley.
Ecosystem carbon balance in the Hawaiian Islands under different scenarios of future climate and land use change
Released September 29, 2021 10:27 EST
2021, Environmental Research Letters (16)
Paul Selmants, Benjamin M. Sleeter, Jinxun Liu, Tamara Wilson, Clay Trauernicht, Abby G. Frazier, Gregory P. Asner
The State of Hawai'i passed legislation to be carbon neutral by 2045, a goal that will partly depend on carbon sequestration by terrestrial ecosystems. However, there is considerable uncertainty surrounding the future direction and magnitude of the land carbon sink in the Hawaiian Islands. We used the Land Use and Carbon Scenario Simulator (LUCAS), a spatially explicit stochastic simulation model that integrates landscape change and carbon gain-loss, to assess how projected future changes in climate and land use will influence ecosystem carbon balance in the Hawaiian Islands under all combinations of two radiative forcing scenarios (RCPs 4.5 and 8.5) and two land use scenarios (low and high) over a 90 year timespan from 2010 to 2100. Collectively, terrestrial ecosystems of the Hawaiian Islands acted as a net carbon sink under low radiative forcing (RCP 4.5) for the entire 90 year simulation period, with low land use change further enhancing carbon sink strength. In contrast, Hawaiian terrestrial ecosystems transitioned from a net sink to a net source of CO2 to the atmosphere under high radiative forcing (RCP 8.5), with high land use accelerating this transition and exacerbating net carbon loss. A sensitivity test of the CO2 fertilization effect on plant productivity revealed it to be a major source of uncertainty in projections of ecosystem carbon balance, highlighting the need for greater mechanistic understanding of plant productivity responses to rising atmospheric CO2. Long-term model projections such as ours that incorporate the interactive effects of land use and climate change on regional ecosystem carbon balance will be critical to evaluating the potential of ecosystem-based climate mitigation strategies.
Compositional evolution of organic matter in Boquillas Shale across a thermal gradient at the single particle level
Released September 29, 2021 07:40 EST
2021, International Journal of Coal Geology (248)
Justin E. Birdwell, Aaron M. Jubb, Paul C. Hackley, Javin J. Hatcherian
Optimization of salt marsh management at the Rachel Carson National Wildlife Refuge, Maine, through use of structured decision making
Released September 28, 2021 09:20 EST
2021, Open-File Report 2021-1080
Hilary A. Neckles, James E. Lyons, Jessica L. Nagel, Susan C. Adamowicz, Toni Mikula, Kathleen M. O'Brien, Bri Benvenuti, Ryan Kleinert
Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop an example of a prototype tool for optimizing tidal marsh management decisions for selected marsh management units at the Rachel Carson National Wildlife Refuge in Maine. The goal was to create a prototype that could be available for future implementation. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of seven marsh management units within the refuge and estimated the outcomes of each action in terms of regional performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that could be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per marsh management unit, that could maximize total management benefits at different cost constraints at the refuge scale.
Management costs were estimated using limited available information, and estimated costs of individual management actions reflected relative differences among actions rather than actual expected expenditures. Results from this prototype showed how, for the objectives, actions, and estimated outcomes used for this example, total management benefits may increase consistently up to a certain estimated cost, and may continue to increase, at a lower rate, with further expenditures. Potential management actions in optimal portfolios at moderate total estimated costs included breaching or removing dikes, roads, or embankments; planting Spartina alterniflora (smooth cordgrass); and digging runnels, or shallow creeks, on the marsh platform to improve surface-water drainage. Potential management actions in optimal portfolios at high estimated costs (for example, up to $550,000) included breaching embankments to restore tidal exchange followed by planting salt marsh vegetation. The potential management benefits were derived from predicted increases in the numbers of tidal marsh obligate birds and spiders (as an indicator of trophic health), and expected improvement in the capacity of marsh elevation to keep pace with sea-level rise and reduced duration of marsh-surface inundation. The prototype presented here does not resolve current management decisions; rather, it provides a framework for decision making at the Rachel Carson National Wildlife Refuge that can be updated for implementation as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuges.
National assessment of helium resources within known natural gas reservoirs
Released September 28, 2021 08:50 EST
2021, Scientific Investigations Report 2021-5085
Sean T. Brennan, Jennifer L. Rivera, Brian A. Varela, Andy J. Park
Using available data, the U.S. Geological Survey estimated that 306 billion cubic feet of recoverable helium is presently within the known geologic natural gas reservoirs of the United States.
Development of a groundwater-simulation model in the Los Angeles Coastal Plain, Los Angeles County, California
Released September 28, 2021 08:36 EST
2021, Scientific Investigations Report 2021-5088
Scott Paulinski, editor(s)
The Los Angeles Coastal Plain (LACP) covers about 580 square miles and is the largest coastal plain of semiarid southern California. The LACP is heavily developed with mostly residential, commercial, and industrial land uses that rely heavily on groundwater for water supply. In 2010, the LACP was home to about 14 percent of California’s population, or about 5.4 million residents. The LACP is also a major commercial and industrial hub with industries including manufacturing, aerospace, entertainment, and tourism.
There has been a heavy reliance on groundwater from the LACP for many years. An average of 305,000 acre-feet per year (acre-ft/yr) of groundwater was used annually from the LACP from 1971 to 2015. The need to replenish the groundwater basins within the LACP was recognized as far back as the 1930s, when spreading grounds were first used to replenish groundwater basins and store water underground during times of water surplus to meet demands in times of shortage. Seawater intrusion resulting from freshwater pumping was first observed in the 1940s. As a result, injection of imported water through wells at what is now the West Coast Basin Barrier Project began on an experimental basis in 1951. Managed aquifer recharge from the spreading grounds and barrier wells is now a substantial component of the LACP’s groundwater supply. The average annual recharge from water spreading from 1971 to 2015 was about 120,000 acre-ft/yr, and the average annual injection into the barrier wells was about 33,000 acre-ft/yr. Other inflows include areal recharge, underflow from San Gabriel and San Fernando Valleys, and onshore flow from the ocean. The average annual recharge from these sources was 100,000 acre-feet (acre-ft) from 1971 to 2015. Additionally, cross-boundary flow from Orange County into the western Orange County subareas of the LACP was simulated as 48,000 acre-ft from 1971 to 2015.
This study, conducted in cooperation with the Water Replenishment District of Southern California (WRD), involved an assessment of the historical and present status of groundwater resources in the LACP and the development of tools to better understand the groundwater system. These efforts were built upon results from previous studies and incorporate new information and developments in modeling capabilities to provide a more detailed analysis of the aquifer systems.
This study includes a comprehensive compilation of geologic and hydrologic data (Chapter A), development of a chronostratigraphic model that provides a detailed description of the LACP aquifer systems (Chapter B), characterization of the groundwater hydrology of the LACP, including a down-hole analysis of grain size using lithologic and geophysical logs (Chapter C), and development and application of the Los Angeles Coastal Plain Groundwater-flow Model (LACPGM) to simulate past groundwater conditions, estimate groundwater-budget components and flow paths, and approximate future groundwater conditions under different scenarios (Chapter D).
Late Cenozoic tephrochronology of the Mount Diablo area within the evolving plate-tectonic boundary zone of northern California
Released September 27, 2021 07:44 EST
2021, GSA Memoirs (217) 393-441
Andrei Sarna-Wojcicki, Raymond Sullivan, Alan L. Deino, Laura Walkup, J. Ross Wagner, Elmira Wan
Schistosome infection in Senegal is associated with different spatial extents of risk and ecological drivers for Schistosoma haematobium and S. mansoni
Released September 27, 2021 07:22 EST
2021, PLoS Neglected Tropical Diseases (15)
Isabel J. Jones, Susanne H. Sokolow, Andrew J Chamberlin, Andrea J Lund, Nicolas Jouanard, Lydie Bandagny, Raphaël Ndione, Simon Senghor, Anne-Marie Schacht, Gilles Riveau, Skylar R. Hopkins, Jason R. Rohr, Justin V. Remais, Kevin D. Lafferty, Armand M. Kuris, Chelsea L. Wood, Giulio A. De Leo
Assessing potential groundwater-level declines from future withdrawals in the Hualapai Valley, northwestern Arizona
Schistosome parasites infect more than 200 million people annually, mostly in sub-Saharan Africa, where people may be co-infected with more than one species of the parasite. Infection risk for any single species is determined, in part, by the distribution of its obligate intermediate host snail. As the World Health Organization reprioritizes snail control to reduce the global burden of schistosomiasis, there is renewed importance in knowing when and where to target those efforts, which could vary by schistosome species. This study estimates factors associated with schistosomiasis risk in 16 villages located in the Senegal River Basin, a region hyperendemic for Schistosoma haematobium and S. mansoni. We first analyzed the spatial distributions of the two schistosomes’ intermediate host snails (Bulinus spp. and Biomphalaria pfeifferi, respectively) at village water access sites. Then, we separately evaluated the relationships between human S. haematobium and S. mansoni infections and (i) the area of remotely-sensed snail habitat across spatial extents ranging from 1 to 120 m from shorelines, and (ii) water access site size and shape characteristics. We compared the influence of snail habitat across spatial extents because, while snail sampling is traditionally done near shorelines, we hypothesized that snails further from shore also contribute to infection risk. We found that, controlling for demographic variables, human risk for S. haematobium infection was positively correlated with snail habitat when snail habitat was measured over a much greater radius from shore (45 m to 120 m) than usual. S. haematobium risk was also associated with large, open water access sites. However, S. mansoni infection risk was associated with small, sheltered water access sites, and was not positively correlated with snail habitat at any spatial sampling radius. Our findings highlight the need to consider different ecological and environmental factors driving the transmission of each schistosome species in co-endemic landscapes.
Released September 27, 2021 07:14 EST
2021, Scientific Investigations Report 2021-5077
Jacob E. Knight, Bruce Gungle, Jeffrey R. Kennedy
A numerical groundwater flow model of the Hualapai Valley Basin in northwestern Arizona was developed to assist water-resource managers in understanding the potential effects of projected groundwater withdrawals on groundwater levels in the basin. The Hualapai Valley Hydrologic Model (HVHM) simulates the hydrologic system for the years 1935 through 2219, including future withdrawal scenarios that simulate large-scale agricultural expansion with and without enhanced groundwater recharge from potential new infiltration basin projects. HVHM is a highly parameterized model (75,586 adjustable parameters) capable of simulating grid-scale variability in aquifer properties (for example, conductivity, specific yield, and specific storage) and system stresses (for instance, natural recharge and groundwater withdrawals). Parameter estimation and uncertainty quantification were performed using an iterative ensemble smoother software (PESTPP-IES) to produce an ensemble of models fit to historical data. Results via the future withdrawal scenario from this ensemble indicate that mean groundwater level will decline at wells in the Kingman subbasin 87 to 128 feet by the year 2050 and 204 to 241 feet by the year 2080. Mean groundwater level is expected to decline at wells in the Hualapai subbasin between 44 and 210 feet by 2050 and between 107 and 350 feet by 2080. The enhanced recharge scenario results show potential for these declines to be partially mitigated in the Kingman subbasin by between 8 and 23 feet in 2050 and between 23 and 43 feet in 2080. The enhanced recharge scenario has no simulated effect on groundwater levels in the Hualapai subbasin. All planned enhanced infiltration projects are located in the Kingman subbasin, which is simulated to become hydraulically disconnected from the Hualapai subbasin owing to groundwater-level declines before 2050. Mean depth to water in the Kingman subbasin as simulated in the future withdrawal scenario will exceed 1,200 feet between the years 2155 and 2214 (median year 2171). In the future withdrawal plus enhanced recharge scenario, mean depth to water in the Kingman subbasin exceeds 1,200 feet between the years 2163 and 2207 (median year 2180), except for one model realization in which the subbasin does not reach an mean depth to water of 1,200 feet by the end of forecast simulation (year 2220). Simulated dewatering of the basin margins reduces scenario pumping rates by as much as 7 percent in 2029 and 12 percent in 2079 below specified rates. Forecasts of groundwater-level declines are based on the reduced simulated pumping rates.
Shifting correlations among multiple aspects of weather complicate predicting future demography of a threatened species
Released September 26, 2021 07:40 EST
2021, Ecosphere (12)
Allison M Louthan, Jeffrey R. Walters, Adam Terando, Victoria Garcia, William F Morris
Culverts delay upstream and downstream migrations of river herring (Alosa spp.)
Most studies of the ecological effects of climate change consider only a limited number of weather drivers that could affect populations, though we know that multiple weather drivers can simultaneously affect population growth rate. Multiple drivers could simultaneously increase/decrease one vital rate, or one may increase a vital rate while another decreases the same vital rate. Considering the impact of multiple weather drivers on vital rates is particularly important in a changing climate, in which correlations among drivers may not be preserved in the future. We used a long-term dataset on the endangered red-cockaded woodpecker (Dryobates borealis) to understand how multiple weather drivers jointly affect survival and reproductive vital rates and then assessed the contributions of individual weather drivers to historical trends in vital rates over time. We found that vital rates were often influenced by more than one weather driver and that weather drivers most commonly exerted opposing effects. For instance, some weather drivers increased vital rates over time, while others acted in the opposite direction, decreasing vital rates over time. Importantly, the historical correlations among weather drivers are almost always projected to change in the future climate, such that future trends in vital rates may not match historical trends. For example, we do not find historical trends in adult survival, but changing correlations among weather drivers could generate future trends in this vital rate. Our work provides an example of how multiple weather drivers can control a variety of vital rates and also illustrates how changes in the correlation structure of weather drivers through time might substantially affect future trends in individual and population performance.
Released September 26, 2021 07:10 EST
2021, River Research and Applications
Derrick Alcott, Elsa Goerig, Theodore R. Castro-Santos
A simplified method for rapid estimation of emergency water supply needs after earthquakes
Alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis) are iteroparous anadromous fish found throughout the East Coast of North America. The phenology of anadromous fish migrations is important for fitness, and the duration of spawning migrations has been compressed in recent years in response to climate change. Anthropogenic barriers to movement, such as dams and culverts at road-stream crossings, can further disrupt migration phenology by delaying movement and increasing predation risk. We used passive integrated transponder (PIT) telemetry to quantify upstream and downstream migratory delay at five road-stream-crossing culverts on the Herring River (MA, USA). Groundspeeds were reduced at all culverts in both directions, confirming that the culverts impede movement despite high passage proportions. The cumulative delay of the culverts on the upstream migration was sufficient to more than double the amount of time required to traverse the river if the culverts had been absent. Furthermore, the presence of snapping turtles (Chelydra serpentina) ambushing river herring within one of the culverts resulted in reduced passage rates beyond the reduction in movement caused by the physical structure itself. This highlights that physical barriers can create cascading ecological consequences and the importance of taking a holistic approach to understanding barrier effects.
Released September 25, 2021 09:53 EST
2021, Water (13)
Joseph Charles Toland, Anne Wein
Researchers are investigating the problem of estimating households with potable water service outages soon after an earthquake. Most of these modeling approaches are computationally intensive, have large proprietary data collection requirements or lack precision, making them unfeasible for rapid assessment, prioritization, and allocation of emergency water resources in large, complex disasters. This study proposes a new simplified analytical method—performed without proprietary water pipeline data—to estimate water supply needs after earthquakes, and a case study of its application in the HayWired earthquake scenario. In the HayWired scenario—a moment magnitude (Mw) 7.0 Hayward Fault earthquake in the San Francisco Bay Area, California (USA)—an analysis of potable water supply in two water utility districts was performed using the University of Colorado Water Network (CUWNet) model. In the case study, application of the simplified method extends these estimates of household water service outage to the nine counties adjacent to the San Francisco Bay, aggregated by a ~250 m2 (nine-arcsecond) grid. The study estimates about 1.38 million households (3.7 million residents) out of 7.6 million residents (2017, ambient, nighttime population) with potable water service outage soon after the earthquake—about an 8% increase from the HayWired scenario estimates.
Managing water resources on Long Island, New York, with integrated, multidisciplinary science
Released September 24, 2021 14:10 EST
2021, Fact Sheet 2021-3044
Robert F. Breault, John P. Masterson, Christopher E. Schubert, Liv M. Herdman
Nutrients, harmful algal blooms, and synthetic chemicals like per- and polyfluoroalkyl substances (PFAS) and 1,4-dioxane threaten Long Island’s water resources by affecting the quality of drinking water and ecologically sensitive habitats that support the diverse wildlife throughout the island. Understanding the occurrence, fate, and transport of these potentially harmful chemicals is critical to protect these vital resources. The U.S. Geological Survey (USGS) is collecting and analyzing data to support informed water-resource management decisions. This fact sheet introduces ongoing efforts and future areas of study aimed to help water professionals develop a comprehensive science strategy to address contamination of the Long Island aquifer system, the sole source of drinking water for nearly 3 million people. These studies include surface and groundwater collection and groundwater flow modeling. Funding for the data collection has been provided by the USGS, New York State Department of Environmental Conservation, New York City Department of Environmental Protection, Suffolk County Water Authority, Nassau County Department of Public Works, State and local agencies, and Tribal and Federal partners. Without the foresight and long-term commitment of these funding partners, evaluating sustainability and planning for future water needs would not be possible.
Evaluating the state-of-the-art in remote volcanic eruption characterization Part I: Raikoke volcano, Kuril Islands
Released September 24, 2021 10:28 EST
2021, Journal of Volcanology and Geothermal Research (419) 1-14
Kathleen McKee, Cassandra Marie Smith, Kevin Reath, Eveanjelene Snee, Sean Maher, Robin S. Matoza, Simon A Carn, Larry G. Mastin, Kyle R. Anderson, David Damby, Diana Roman, Artem Degterev, Alexander Rybin, Marina Chibisova, Jelle D. Assink, Rodrigo de Negri Levia, Anna Perttu
Raikoke, a small, unmonitored volcano in the Kuril Islands, erupted in June 2019. We integrate data from satellites (including Sentinel-2, TROPOMI, MODIS, Himawari-8), the International Monitoring System (IMS) infrasound network, and global lightning detection network (GLD360) with information from local authorities and social media to retrospectively characterize the eruptive sequence and improve understanding of the pre-, syn- and post- eruptive behavior. We observe six infrasound pulses beginning on 21 June at 17:49:55 UTC as well as the main Plinian phase on 21 June at 22:29 UTC. Each pulse is tracked in space and time using lightning and satellite imagery as the plumes drift eastward. Post-eruption visible satellite imagery shows expansion of the island's surface area, an increase in crater size, and a possibly-linked algal bloom south of the island. We use thermal satellite imagery and plume modeling to estimate plume height at 10–12 km asl and 1.5–2 × 106 kg/s mass eruption rate. Remote infrasound data provide insight into syn-eruptive changes in eruption intensity. Our analysis illustrates the value of interdisciplinary analyses of remote data to illuminate eruptive processes. However, our inability to identify deformation, pre-eruptive outgassing, and thermal signals, which may reflect the relatively short duration (~12 h) of the eruption and minimal land area around the volcano and/or the character of closed-system eruptions, highlights current limitations in the application of remote sensing for eruption detection and characterization.
Methods for estimating regional skewness of annual peak flows in parts of eastern New York and Pennsylvania, based on data through water year 2013
Released September 24, 2021 09:50 EST
2021, Scientific Investigations Report 2021-5015
Andrea G. Veilleux, Daniel M. Wagner
Bulletin 17C (B17C) recommends fitting the log-Pearson Type III (LP−III) distribution to a series of annual peak flows at a streamgage by using the method of moments. The third moment, the skewness coefficient (or skew), is important because the magnitudes of annual exceedance probability (AEP) flows estimated by using the LP–III distribution are affected by the skew; interest is focused on the right-hand tail of the distribution, which represents the larger annual peak flows that correspond to small AEPs. For streamgages having modest record lengths, the skew is sensitive to extreme events like large floods, which cause a sample to be highly asymmetrical or “skewed.” For this reason, B17C recommends using a weighted-average skew computed from the skew of the annual peak flows for a given streamgage and a regional skew. This report presents an estimate of regional skew for a study area encompassing parts of eastern New York and Pennsylvania. A total of 232 candidate U.S. Geological Survey streamgages that were unaffected by extensive regulation, diversion, urbanization, or channelization were considered for use in the skew analysis; after screening for redundancy and pseudo record length (PRL) of at least 36 years, 183 streamgages were selected for use in the study.
Flood frequencies for candidate streamgages were analyzed by employing the expected moments algorithm, which extends the method of moments so that it can accommodate interval, censored, and historical/paleo flow data, as well as the multiple Grubbs-Beck test to identify potentially influential low floods in the data series. Bayesian weighted least squares/Bayesian generalized least squares regression was used to develop a regional skew model for the study area that would incorporate possible variables (basin characteristics) to explain the variation in skew in the study area. Ten basin characteristics were considered as possible explanatory variables; however, none produced a pseudo coefficient of determination greater than 1 percent; as a result, these characteristics did not help to explain the variation in skew in the study area. Therefore, a constant model that had a regional skew coefficient of 0.32 and an average variance of prediction at a new streamgage (AVPnew, which corresponds to the mean square error [MSE] of 0.11) was selected. The AVPnew corresponds to an effective record length of 68 years, a marked improvement over the Bulletin 17B national skew map, whose reported MSE of 0.302 indicated a corresponding effective record length of only 17 years.
Multidisciplinary constraints on magma compressibility, the pre-eruptive exsolved volatile fraction, and the H2O/CO2 molar ratio for the 2006 Augustine eruption, Alaska
Released September 24, 2021 09:41 EST
2021, Geochemistry, Geophysics, Geosystems (G-Cubed) (22) 1-24
Valerie K. Wasser, Taryn M. Lopez, Kyle R. Anderson, Pavel E. Izbekov, Jeffrey T. Freymueller
Geodetically modeled reservoir volume changes during volcanic eruptions are commonly much smaller than the observed eruptive volumes. This discrepancy is thought to be partially due to the compressibility of magma, which is largely controlled by the presence of exsolved volatiles. The 2006 eruption of Augustine Volcano, Alaska, produced an eruptive volume that was ∼3 times larger than the geodetically estimated syn-eruptive subsurface volume change. In this study, we use a multistep methodology that combines constraints from geodetic, volcanic gas, geologic, and petrologic data together with equations relating physical processes to observable parameters. We apply a Monte Carlo approach to quantify uncertainties. Ultimately, we solve for the exsolved volatile volume fraction and the magma compressibility. We estimate Augustine's 2006 pre-eruptive exsolved volatile phase to be ∼5.5 vol% of the magma at storage depths, yielding a bulk magma compressibility of ∼3.8 × 10−10 Pa−1. We develop a novel approach to estimate the H2O/CO2 ratio of the syn-eruptive gas emissions in the absence of direct H2O emission measurements which are hard to obtain due to the high background levels in ambient air. We find a best-fit H2O/CO2 molar ratio of 29. We also investigate the effects of applying different equations of state to our model. We find that the Ideal Gas Law might be used as a first approximation due to its simplicity; however, it overestimates volatile density and compressibility significantly at storage depths. This project capitalizes on the insights that can be gained by integrating multidisciplinary data with models of physical processes.
The Biscuit Brook and Neversink Reservoir Watersheds: Long-term investigations of stream chemistry, soil chemistry, and aquatic ecology in the Catskill Mountains, New York, USA, 1983 to 2020
Released September 24, 2021 08:50 EST
2021, Hydrological Processes (35)
Peter S. Murdoch, Douglas A. Burns, Michael McHale, Jason Siemion, Barry P. Baldigo, Gregory B. Lawrence, Scott D. George, Michael Antidormi, Donald B. Bonville
This data note describes the Biscuit Brook and Neversink Reservoir watershed Long-Term Monitoring Data that includes: 1) stream discharge, (1983 – 2020 for Biscuit Brook and 1937 – 2020 for the Neversink Reservoir watershed), 2) stream water chemistry, 1983-2020, at 4 stations, 3) fish survey data from 16 locations in the watershed 1990-2019, 4) soil chemistry data from 2 headwater sub-watersheds, 1993-2012, and 5) periodic stream water chemistry sampling data from 364 locations throughout the watershed, 1983-2020. The Neversink Reservoir watershed in the Catskill Mountains of New York, USA drains an area of 172.5 km2. The watershed feeds one of 6 reservoirs in New York City's West of Hudson water supply, which accounts for about 90% of the city's water supply. Biscuit Brook is a 9.63 km2 tributary sub-watershed within the Neversink Reservoir watershed.
miR133b microinjection during early development targets transcripts of sardiomyocyte ion channels and induces oil-like cardiotoxicity in zebrafish (Danio rerio) embryos
Released September 24, 2021 07:40 EST
2021, Chemical Research in Toxicology (34) 2209-2215
Justin Blaine Greer, Jason T. Magnuson, Victoria McGruer, Le Qian, Subham Dasgupta, David C. Volz, Daniel Schlenk
Historical streamflow and stage data compilation for the Lower Columbia River, Pacific Northwest
Previous studies have shown that altered expression of a family of small noncoding RNAs (microRNAs, or miRs) regulates the expression of downstream mRNAs and is associated with diseases and developmental disorders. miR133b is highly expressed in mammalian cardiac and skeletal muscle, and aberrant expression is associated with cardiac disorders and electrophysiological changes in cardiomyocytes. Similarly, cardiac dysfunction has been observed in early life-stage mahi-mahi (Coryphaena hippurus) exposed to crude oil, a phenotype that has been associated with an upregulation of miR133b as well as subsequent downregulation of a delayed rectifier potassium channel (IKr) and calcium signaling genes that are important for proper heart development during embryogenesis. To examine the potential role of miR133b in oil-induced early life-stage cardiotoxicity in fish, cleavage-stage zebrafish (Danio rerio) embryos were either (1) microinjected with ∼3 nL of negative control miR (75 μM) or miR133b (75 μM) or (2) exposed to a treatment solution containing 5 μM benzo(a)pyrene (BaP), a model polycyclic aromatic hydrocarbon, as a positive control. At 72 h post fertilization (hpf), miR133b-injected fish exhibited BaP-like cardiovascular malformations, including a significantly increased pericardial area relative to negative control miR-injected embryos, as well as a significantly reduced eye area. qPCR revealed that miR133b microinjection decreased the abundance of cardiac-specific IKrkcnh6 at 5 hpf, which may contribute to action potential elongation in oil-exposed cardiomyocytes. Additionally, ryanodine receptor 2, a crucial calcium receptor in the sarcoplasmic reticulum, was also downregulated by miR133b. These results indicate that an oil-induced increase in miR133b may contribute to cardiac abnormalities in oil-exposed fish by targeting cardiac-specific genes essential for proper heart development.
Released September 24, 2021 07:39 EST
2021, Open-File Report 2020-1138
Carrie L. Boudreau, Marc A. Stewart, Adam J. Stonewall
The U.S. Geological Survey mined data from a variety of national and state agencies including USGS, Oregon Water Resources Department, National Oceanic and Atmospheric Administration, Washington Department of Ecology, Pacific Northwest National Laboratory, Portland State University, and U.S. Army Corps of Engineers. A comprehensive dataset of streamflow, stage, and tidal elevations for the Lower Columbia River basin was compiled. Data were compiled from gaging stations in Oregon and Washington along the Columbia River from Astoria to The Dalles and along the Willamette River from Salem to Portland. Tidal gages along the Washington, Oregon, and California coasts were also compiled. Seasonal maximum values were calculated for both streamflow and stage for the winter (November–March) and spring (April–July) flow seasons, as well as for the full water year when underlying data were available. The aggregated datasets are available at https://doi.org/10.5066/P9R6RT0Z.
Survival and spawning success of American shad (Alosa sapidissima) in varying temperatures and levels of glochidia infection
Released September 24, 2021 07:30 EST
2021, Fish Physiology and Biochemistry
Shannon M Bayse, Amy M. Regish, Stephen D. McCormick
Staggered-entry analysis of breeding phenology and occupancy dynamics of Arizona toads from historically occupied habitats of New Mexico, USA
Temperature fluctuations and climate change impacts may substantially affect spawning success of fish, especially migratory species with a limited spawning window. Factors affecting American shad (Alosa sapidissima) spawning success and survival were investigated at different temperatures and periods (peak- and late-spawning periods) during the Connecticut River, USA, spawning migration in 2017. Wild caught American shad were exposed to constant temperatures regimes of 15, 18, 21, 24 and 27 °C for 2 weeks. During the peak-spawning period, an increase in temperature (15–24 °C) was shown to increase spawning success factors, including spawning probability, number of eggs, and fertilization success, but decreased egg size. Temperatures between 18 and 27 °C did not affect these factors during the late-spawning period. Glochidia infection by the alewife floater (Anodonta implicata) was much higher in the late-spawning period and significantly decreased the survival of American shad. Further research should investigate the parasite-host relationship between the alewife floater and American shad to determine annual variability of glochidia infections and how they affect American shad from physiological and passage perspectives. Higher temperatures were shown to increase spawning success of American shad during the peak-spawning period, but temperature had no effect during the late-spawning period. However, any effect during the late-spawning period may have been masked by a high level of glochidia infection.
Released September 24, 2021 07:30 EST
2021, Ichthyology & Herpetology 851-859
MJ Forzley, Mason J. Ryan, IM Latella, JT Giermakowski, Erin L. Muths, Brent H. Sigafus, Blake R. Hossack
Effects of variable-density thinning on non-native understory plants in coniferous forests of the Pacific Northwest
For species with variable phenology, it is often challenging to produce reliable estimates of population dynamics or changes in occupancy. The Arizona Toad (Anaxyrus microscaphus) is a southwestern USA endemic that has been petitioned for legal protection, but status assessments are limited by a lack of information on population trends. Also, timing and consistency of Arizona Toad breeding varies greatly, making it difficult to predict optimal survey times or effort required for detection. To help fill these information gaps, we conducted breeding season call surveys during 2013–2016 and 2019 at 86 historically occupied sites and 59 control sites across the species' range in New Mexico. We estimated variation in mean dates of arrival and departure from breeding sites, changes in occupancy, and site-level extinction since 1959 with recently developed multi-season staggered-entry models, which relax the within-season closure assumption common to most occupancy models. Optimal timing of surveys in our study areas was approximately 5–30 March. Averaged across years, estimated probability of occupancy was 0.58 (SE = 0.09) for historical sites and 0.19 (SE = 0.08) for control sites. Occupancy increased from 2013 through 2019. Notably, even though observer error was trivial, annual detection probabilities varied from 0.23 to 0.75 and declined during the study; this means naïve occupancy values would have been misleading, indicating apparent declines in toad occupancy. Occupancy was lowest during the first year of the study, possibly due to changes in stream flows and conditions in many waterbodies following extended drought and recent wildfires. Although within-season closure was violated by variable calling phenology, simple multi-season models provided nearly identical estimates as staggered-entry models. Surprisingly, extinction probability was unrelated to the number of years since the first or last record at historically occupied sites. Collectively, our results suggest a lack of large, recent declines in occupancy by Arizona Toads in New Mexico, but we still lack population information from most of the species' range.
Released September 24, 2021 06:58 EST
2021, Forest Ecology and Management (502)
Yianna Bekris, Janet Prevey, Leslie C. Brodie, Connie Harrington
Discharge and dissolved-solids characteristics of Blacks Fork above Smiths Fork, Wyoming, April 2018 through September 2019
Released September 23, 2021 22:04 EST
2021, Scientific Investigations Report 2021-5095
Cheryl A. Eddy-Miller, Jerrod D. Wheeler, Ruth M. Law, Shaun W. Moran
The Colorado River Basin Salinity Control Forum was formed in 1973 to coordinate salinity control efforts among the States in the Colorado River Basin, including Wyoming. The Colorado River Salinity Control Act of 1974 (Public Law 93–320) authorized “the construction, operation, and maintenance of certain works in the Colorado River Basin to control the salinity of water delivered to users in the United States and Mexico.” Water-quality standards for salinity in the lower Colorado River Basin were adopted in 1975. To help meet these standards, the Bureau of Reclamation, Natural Resource Conservation Service, and States within the Colorado River Basin have implemented salinity control projects that focus on reducing salt loading associated with irrigated agriculture by improving water delivery systems and water management practices. The term salinity is synonymous with dissolved solids in this report.
The Bureau of Reclamation, in conjunction with the Colorado River Basin Salinity Control Forum, was interested in determining the contribution of dissolved solids from Blacks Fork above Smiths Fork to the Colorado River and initiated a study of Blacks Fork above Smiths Fork in 2018. In early 2018, the U.S. Geological Survey installed a streamgage at the most downstream location on the Blacks Fork, upstream from the convergence with Smiths Fork, to characterize the stream. The Blacks Fork above Smiths Fork, near Lyman, Wyoming, streamgage (U.S. Geological Survey identifier 09219200) was operated from April 4, 2018, through September 30, 2019, collecting continuous stream stage and specific-conductance data, from which continuous discharge, dissolved-solids concentrations, and dissolved-solids loads were calculated. Seven sites were selected on Blacks Fork and a tributary to describe a snapshot of the discharge and dissolved-solids characteristics. These sites were sampled during July, August, and September 2018 and June, July, August, and September 2019 report.
Discharge at the Blacks Fork above Smiths Fork, near Lyman, Wyo., streamgage (09219200) from April through September in 2018 was lower and less variable than during the same period in 2019. The mean daily (mean of the daily means) discharge during those 6 months in 2018 (15.1 cubic feet per second [ft3/s]) was about one-tenth of the discharge during the same period in 2019 (152 ft3/s). The cumulative monthly discharge during April through September in 2018 was 5,360 acre-feet, about one-tenth of the discharge during the same period in 2019 which was 54,700 acre-feet. Similar differences in discharge between the 2018 and 2019 periods also are noted at other Blacks Fork streamgages in the area.
Continuous specific conductance data and the statistical relation between specific conductance and dissolved-solids concentrations were used to calculate the daily mean dissolved-solids concentrations. Dissolved solids often have an inverse relation with discharge because higher discharges typically have a diluting effect that lowers the dissolved-solids concentrations. In general, when discharges at the Blacks Fork above Smiths Fork streamgage (09219200) are higher, dissolved-solids concentrations are generally lower. However, the high dissolved-solids concentrations that are measured during high discharges indicate that the system has natural variability and the dissolved-solids concentrations are determined by more factors than just discharge. The mean daily dissolved-solids concentration during April through September 2018 was 1,630 milligrams per liter and during the same period in 2019 was 1,100 milligrams per liter.
Dissolved-solids loads were calculated as the product of the discharge and dissolved-solids concentration. The daily mean dissolved-solids loads during 2018 were typically lower than during 2019. This result is primarily because the discharge was much lower in 2018 than in 2019. Therefore, although the daily mean dissolved-solids concentrations tended to be higher in 2018, the substantially higher discharges in 2019 had more of an effect on the dissolved-solids loads than the dissolved-solids concentrations.
The cumulative dissolved-solids load at the Blacks Fork above Smiths Fork, near Lyman, Wyo., streamgage (09219200) during the 18-month study was 81,200 tons, with a mean daily load of 149 tons per day. During the 6-month period from April through September 2018, the cumulative dissolved-solids load at the streamgage was estimated to be 8,740 tons and, during the same 6 months in 2019, the cumulative dissolved-solids load was estimated to be 60,900 tons. During the fall and winter between the two periods, the cumulative dissolved-solids load was 11,600 tons.
Discharge and dissolved-solids concentrations from samples collected during the synoptic sampling events were highly variable among most sites during most synoptic sampling events and also highly variable at most sites among different sampling events. The two sites upstream from the tributary input from Threemile Creek had lower dissolved-solids concentrations than sites including and downstream from the tributary. Sites including and downstream from the tributary had similar values and variability of dissolved-solids loads, with the exception of the farthest downstream site at the Blacks Fork above Smiths Fork, near Lyman, Wyo., streamgage (09219200) that tended to have larger dissolved-solids loads and higher variability among synoptic sampling events.
Hydrogeologic framework of the Big Lost River Basin, south-central Idaho, chap. A of Zinsser, L.M., ed., Characterization of water resources in the Big Lost River Basin, south-central Idaho
Released September 23, 2021 13:00 EST
2021, Scientific Investigations Report 2021-5078-A
Lauren M. Zinsser
Surface-water and groundwater resources in the Big Lost River Basin of south-central Idaho are extensively interconnected; this interchange affects and is affected by water-resource management for irrigated agriculture and other uses in the basin. Concerns from water users regarding declining groundwater levels, declining streamflows, and drought helped motivate an updated evaluation of water resources in the Big Lost River Basin. The hydrogeologic framework presented in this report provides a conceptual basis for understanding groundwater resources in the Big Lost River Basin and comprises three major parts: (1) conceptual description of four hydrogeologic units, (2) development of a three-dimensional hydrogeologic framework model representing the spatial distribution of the hydrogeologic units, and (3) a description of groundwater occurrence and movement. This hydrogeologic framework represents the first of three planned reports describing water resources in the Big Lost River Basin; subsequent reports are intended to present a groundwater budget for the basin and to describe the results of a series of events measuring gains to and losses from streamflow in the Big Lost River. This report was prepared by the U.S. Geological Survey in cooperation with the Idaho Department of Water Resources.
The Big Lost River Basin has four hydrogeologic units. First, the Quaternary unconsolidated sediments unit comprises the basin-fill alluvial aquifer and generally is used within 250 feet of the land surface. The Quaternary unconsolidated sediments unit is spatially heterogeneous, with locally confining conditions in some areas, and is the most heavily used hydrogeologic unit in the basin. Second, the Paleozoic sedimentary rocks unit, composed primarily of carbonates with some siliciclastic rocks, represents the major bedrock aquifer and contributes subsurface recharge at the margins of the alluvial aquifer. Third, the Tertiary volcanic rocks unit, composed primarily of andesite and dacite with lesser tuff, is locally important to water production, particularly in faulted and fractured zones. The Paleozoic sedimentary rocks hydrogeologic unit occurs at the valley margins and underlies tributaries throughout the basin, whereas the Tertiary volcanic rocks hydrogeologic unit primarily occurs in uplands in the western one-half of the basin. Fourth, the Quaternary basalt rocks unit consists of multiple basalt flows that are interbedded with the Quaternary unconsolidated sediments unit in the southern end of the Big Lost River Basin and contains at least three water-bearing zones. Insights gained from this updated hydrogeologic framework will help inform current water-resource management in the Big Lost River Basin.
Earth Resources Observation and Science Center—Keeping watch over Earth's resources
Released September 23, 2021 11:43 EST
2021, Fact Sheet 2021-3052
U.S. Geological Survey
The Earth Resources Observation and Science (EROS) Center is the largest facility of its kind within the U.S. Geological Survey. As both a science and data center, EROS serves a unique and critical role in shaping our understanding of a changing planet.
EROS opened its doors in 1973 as a receiving station, data archive, and data distribution hub for the USGS Landsat series of Earth observing satellites. In the nearly five decades since, EROS has grown into a globally recognized leader in land change science.
Origin of unconsolidated Quaternary deposits at Harriet Point near Redoubt Volcano, Alaska
Released September 23, 2021 09:25 EST
2021, Scientific Investigations Report 2021-5071
Christopher F. Waythomas
Unconsolidated boulder-rich diamicton units exposed in sea cliffs at Harriet Point southeast of Redoubt Volcano were evaluated to better understand their provenance relative to the late Quaternary eruptive history of the volcano. A previous study concluded that deposits at Harriet Point were emplaced by a large volcanic landslide originating on the southeast flank of Redoubt Volcano (Begét and Nye, 1994). Field-based analysis of the stratigraphy and sedimentology of the Harriet Point deposits and numerical simulations of the volcanic landslide area of inundation indicate that none of the deposits are volcanogenic. All of the unconsolidated boulder-rich diamicton units at Harriet Point are glacial in origin and can be reconciled using the presently available model for late Quaternary glaciation of Cook Inlet.
Economic assessment of surface water in the Harney Basin, Oregon
Released September 23, 2021 09:15 EST
2021, Open-File Report 2021-1087
Lucas S. Bair, Matthew Flyr, Christopher Huber
The Harney Basin is a closed river basin in southeastern Oregon. Surface water in the basin is used for a variety of social, economic, and ecological benefits. While some surface water uses compete with one another, others are complementary or jointly produce multiple beneficial outcomes. The objective of this study is to conduct an economic assessment of surface water in the basin as it relates to wet meadow pasture production and outdoor recreation. Given the complex interactions between surface water management on public and private land and the various goods and services that are derived from adequate water resources, an economic assessment of surface water management can be used to assist future decision making in the basin.
Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001–2016
Released September 23, 2021 08:38 EST
2021, Ecology and Evolution
Jeffrey F. Bromaghin, David C. Douglas, George M. Durner, Kristin S. Simac, Todd C. Atwood
The Arctic Ocean is undergoing rapid transformation toward a seasonally ice-free ecosystem. As ice-adapted apex predators, polar bears (Ursus maritimus) are challenged to cope with ongoing habitat degradation and changes in their prey base driven by food-web response to climate warming. Knowledge of polar bear response to environmental change is necessary to understand ecosystem dynamics and inform conservation decisions. In the southern Beaufort Sea (SBS) of Alaska and western Canada, sea ice extent has declined since satellite observations began in 1979 and available evidence suggests that the carrying capacity of the SBS for polar bears has trended lower for nearly two decades. In this study, we investigated the population dynamics of polar bears in Alaska's SBS from 2001 to 2016 using a multistate Cormack–Jolly–Seber mark–recapture model. States were defined as geographic regions, and we used location data from mark–recapture observations and satellite-telemetered bears to model transitions between states and thereby explain heterogeneity in recapture probabilities. Our results corroborate prior findings that the SBS subpopulation experienced low survival from 2003 to 2006. Survival improved modestly from 2006 to 2008 and afterward rebounded to comparatively high levels for the remainder of the study, except in 2012. Abundance moved in concert with survival throughout the study period, declining substantially from 2003 and 2006 and afterward fluctuating with lower variation around an average of 565 bears (95% Bayesian credible interval [340, 920]) through 2015. Even though abundance was comparatively stable and without sustained trend from 2006 to 2015, polar bears in the Alaska SBS were less abundant over that period than at any time since passage of the U.S. Marine Mammal Protection Act. The potential for recovery is likely limited by the degree of habitat degradation the subpopulation has experienced, and future reductions in carrying capacity are expected given current projections for continued climate warming.
Natural history of a bighorn sheep pneumonia epizootic: Source of infection, course of disease, and pathogen clearance
Released September 23, 2021 08:21 EST
2021, Ecology and Evolution
T. E. Besser, E. Frances Cassirer, Amy Lisk, Danielle Nelson, Kezia R. Manlove, Paul Cross, John T. Hogg
A respiratory disease epizootic at the National Bison Range (NBR) in Montana in 2016–2017 caused an 85% decline in the bighorn sheep population, documented by observations of its unmarked but individually identifiable members, the subjects of an ongoing long-term study. The index case was likely one of a small group of young bighorn sheep on a short-term exploratory foray in early summer of 2016. Disease subsequently spread through the population, with peak mortality in September and October and continuing signs of respiratory disease and sporadic mortality of all age classes through early July 2017. Body condition scores and clinical signs suggested that the disease affected ewe groups before rams, although by the end of the epizootic, ram mortality (90% of 71) exceeded ewe mortality (79% of 84). Microbiological sampling 10 years to 3 months prior to the epizootic had documented no evidence of infection or exposure to Mycoplasma ovipneumoniae at NBR, but during the epizootic, a single genetic strain of M. ovipneumoniae was detected in affected animals. Retrospective screening of domestic sheep flocks near the NBR identified the same genetic strain in one flock, presumptively the source of the epizootic infection. Evidence of fatal lamb pneumonia was observed during the first two lambing seasons following the epizootic but was absent during the third season following the death of the last identified M. ovipneumoniae carrier ewe. Monitoring of life-history traits prior to the epizootic provided no evidence that environmentally and/or demographically induced nutritional or other stress contributed to the epizootic. Furthermore, the epizootic occurred despite proactive management actions undertaken to reduce risk of disease and increase resilience in this population. This closely observed bighorn sheep epizootic uniquely illustrates the natural history of the disease including the (presumptive) source of spillover, course, severity, and eventual pathogen clearance.
Evidence for humans in North America during the Last Glacial Maximum
Released September 23, 2021 08:19 EST
2021, Science 1528-1531
Matthew R. Bennett, David Bustos, Jeffrey S. Pigati, Kathleen B. Springer, Thomas. M. Urban, Vance T. Holliday, Sally C. Reynolds, Marcin Budka, Jeffrey S. Honke, Adam M. Hudson, Brendan Fenerty, Clare Connelly, Patrick J. Martinez, Vincent L. Santucci, Daniel Odess
Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. When, how, and from where did people migrate, and what were the consequences of their arrival for the established fauna and landscape are enduring questions. Here, we present evidence from excavated surfaces of in situ human footprints from White Sands National Park (New Mexico, USA), where multiple human footprints are stratigraphically constrained and bracketed by seed layers that yield calibrated ages between ~23 and 21 ka. These findings confirm the presence of humans in North America during the Last Glacial Maximum, adding evidence to the antiquity of human colonization of the Americas, and provide a temporal range extension for the co-existence of early inhabitants and Pleistocene megafauna.
Helium-carbon systematics of groundwaters in the Lassen Peak Region
Released September 23, 2021 08:08 EST
2021, Chemical Geology (584)
Peter Barry, David Bekaert, John Krantz, Saemundor Halldorsson, J. Maarten DeMoor, Tobias Fischer, Cynthia Werner, Peter J. Kelly, Alan Seltzer, Brian Franz, Justin T. Kulongoski
Alpine glacier reveals ecosystem impacts of Europe's prosperity and peril over the last millennium
Released September 23, 2021 06:56 EST
2021, Geophysical Research Letters (48)
Sandra O. Brugger, Margit Schwikowski, Erika Gobet, Christoph Schworer, Christian Rohr, Michael Sigl, Stephan Henne, Christian Pfister, Theo M. Jenk, Paul D. Henne, Willy Tinner
SiteOpt: An open-source R-package for site selection and portfolio optimization
Information about past ecosystem dynamics and human activities is stored in the ice of Colle Gnifetti glacier in the Swiss Alps. Adverse climatic intervals incurred crop failures and famines and triggered reestablishment of forest vegetation but also societal resilience through innovation. Historical documents and lake sediments record these changes at local—regional scales but often struggle to comprehensively document continental-scale impacts on ecosystems. Here, we provide unique multiproxy evidence of broad-scale ecosystem, land use, and climate dynamics over the past millennium from a Colle Gnifetti microfossil and oxygen isotope record. Microfossil data indicate that before 1750 CE forests and fallow land rapidly replaced crop cultivation during historically documented societal crises caused by climate shifts and epidemics. Subsequently, with technology and the introduction of more resilient crops, European societies adapted to the Little Ice Age cold period, but resource overexploitation and industrialization led to new regional to global-scale environmental challenges.
Released September 22, 2021 08:35 EST
Payman G Saghand, Zulqarnain Haider, Hadi Charkhgard, Mitchell Eaton, Julien Martin, Simeon Yurek, Bradley J. Udell
Conservation planning involves identifying and selecting actions to best achieve objectives for managing natural, social and cultural resources. Conservation problems are often high dimensional when specified as combinatorial or portfolio problems and when multiple competing objectives are considered at varying spatial and temporal scales. Although analytical techniques such as modern portfolio theory (MPT) have been developed to address these complex problems, open source computational platforms for executing these approaches are not readily available. We present a user-friendly R-package called SiteOpt for optimization of binary decisions while explicitly considering environmental or economic uncertainty and the risk tolerance of decision makers. We illustrate the package with spatially-explicit site selection problems (i.e. spatial conservation planning), including an option for divestment (i.e. selling assets), when accounting for future uncertainties in designing conservation areas. The tool is applicable to both spatial and non-spatial problems, such as budget allocation or species selection. Constraints for spatial design and spatial dependencies (e.g. connectivity among sites) can also be specified in SiteOpt. Users can optimize site selection based on two competing objectives by solving for the Nash bargaining solution. Importantly, by quantifying uncertainty and asset spatial correlation, a measure of risk can be included as one such objective to be traded off against portfolio benefits. Thus, SiteOpt can be used to explicitly manage risk in portfolio-based spatial optimization. This tool facilitates decisions in a variety of problem settings, including reserve selection, invasive species management, allocation of law enforcement activities for conservation, budget allocation and asset selection under uncertainty and risk.
Drought resistance and resilience: The role of soil moisture–plant interactions and legacies in a dryland ecosystem
Released September 22, 2021 07:18 EST
2021, Journal of Ecology (109) 3280-3294
Dave Hoover, Alix A. Pfennigwerth, Michael C. Duniway
Revisiting the declustering of spatial data with preferential sampling
- In many regions of the world, climate change is projected to reduce water availability through changes in the hydrological cycle, including more frequent and intense droughts, as well as seasonal shifts in precipitation. In water-limited ecosystems, such as drylands, lower soil water availability may exceed the adaptive capacity of many organisms, leading to cascading ecological effects during (concurrent effects) and after drought (legacy effects). The magnitude and duration of concurrent and legacy effects depends on drought intensity, duration and timing as well as the resistance and resilience of the ecosystem.
- Here, we investigated the effects of drought seasonality and plant community composition on two dominant perennial grasses, Achnatherum hymenoides (C3 photosynthesis) and Pleuraphis jamesii (C4 photosynthesis), in a dryland ecosystem. The experiment consisted of three precipitation treatments: control (ambient precipitation), cool-season drought (−66% ambient precipitation November–April) and warm-season drought (−66% ambient precipitation May–October), applied in two plant communities (perennial grasses with or without a large shrub, Ephedra viridis) over a 3-year period. We examined the concurrent and legacy effects of seasonal drought on soil moisture, phenology and biomass.
- Drought treatments had strong concurrent and legacy effects on soil moisture, which impacted the phenology and biomass of the two grasses. Drought reduced growing season length by delaying green-up (cool-season drought) or advancing senescence (warm-season drought) and reduced biomass for both species. Biomass and phenology legacy effects from drought emerged in the second and third years of the experiment. While we observed differential sensitivity to drought legacies between the two grasses, we found limited evidence that shrub presence had interactive effects with the drought treatment.
- Synthesis. The results from this study highlight how abiotic and biotic legacies can develop and influence a community's resistance and resilience to subsequent droughts. When the frequency of repeated extreme events, such as recurring seasonal droughts, exceeds the capacity of organisms or ecosystems to recover (i.e. resilience), persistent drought legacies can reduce the resistance to subsequent drought events. Overall, these results highlight how drought legacies are a product of ecological resistance and resilience to past drought and can influence ecosystem vulnerability to future droughts.
Released September 22, 2021 06:56 EST
2021, Computers & Geosciences (157)
Migration stopover ecology of Cinnamon Teal in western North America
Released September 21, 2021 08:17 EST
2021, Ecology and Evolution
Desmond Alexander Mackell, Michael L. Casazza, Cory T. Overton, J. Patrick Donnelly, David Olson, Fiona McDuie, Joshua T. Ackerman, John M. Eadie
A stable isotope record of late Quaternary hydrologic change in the northwestern Brooks Range, Alaska (eastern Beringia)
Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS-GSM transmitters, we analyzed 61 fall migration tracks across western North America during our three-year study (2017–2019). We marked Cinnamon Teal primarily during spring/summer in important breeding and molting regions across seven states (California, Oregon, Washington, Idaho, Utah, Colorado, and Nevada). We assessed fall migration routes and timing, detected 186 fall stopover sites, and identified specific North American ecoregions where sites were located. We classified underlying land cover for each stopover site and measured habitat selection for 12 land cover types within each ecoregion. Cinnamon Teal selected a variety of flooded habitats including natural, riparian, tidal, and managed wetlands; wet agriculture (including irrigation ditches, flooded fields, and stock ponds); wastewater sites; and golf and urban ponds. Wet agriculture was the most used habitat type (29.8% of stopover locations), and over 72% of stopover locations were on private land. Relatively scarce habitats such as wastewater ponds, tidal marsh, and golf and urban ponds were highly selected in specific ecoregions. In contrast, dry non-habitat across all ecoregions, and dry agriculture in the Cold Deserts and Mediterranean California ecoregions, was consistently avoided. Resources used by Cinnamon Teal often reflected wetland availability across the west and emphasize their adaptability to dynamic resource conditions in arid landscapes. Our results provide much needed information on spatial and temporal resource use by Cinnamon Teal during migration and indicate important wetland habitats for migrating waterfowl in the western United States.
Released September 21, 2021 07:54 EST
2021, Journal of Quaternary Science
Amanda L. King, Lesleigh Anderson, Mark B. Abbott, Mary Edwards, Matthew S. Finkenbinder, Bruce P. Finney, Matthew Wooller
Elevated levels of radiocarbon in methane dissolved in seawater reveal likely local contamination from nuclear powered vessels
A submillennial-resolution record of lake water oxygen isotope composition (δ18O) from chironomid head capsules is presented from Burial Lake, northwest Alaska. The record spans the Last Glacial Maximum (LGM; ~20–16k cal a bp) to the present and shows a series of large lake δ18O shifts (~5‰). Relatively low δ18O values occurred during a period covering the LGM, when the lake was a shallow, closed-basin pond. Higher values characterize deglaciation (~16–11.5k cal a bp) when the lake was still closed but lake levels were higher. A rapid decline between ~11 and 10.5k cal a bp indicates that lake levels rose to overflowing. Lake δ18O values are interpreted to reflect the combined effects of changes in lake hydrology, growing season temperature and meteoric source water as well as large-scale environmental changes impacting this site, including opening of the Bering Strait and shifts in atmospheric circulation patterns related to ice-sheet dynamics. The results indicate significant shifts in precipitation minus evaporation across the late Pleistocene to early Holocene transition, which are consistent with temporal patterns of vegetation change and paludification. This study provides new perspectives on the paleohydrology of eastern Beringia concomitant with human migration and major turnover in megafaunal assemblages.
Released September 21, 2021 07:27 EST
2022, Science of the Total Environment (806)
D.J. Joung, Carolyn D. Ruppel, J. Southon, John D. Kessler
Saltwater intrusion intensifies coastal permafrost thaw
Released September 21, 2021 07:15 EST
2021, Geophysical Research Letters (48)
Julia Guimond, Aaron Mohammad, Michelle A. Walvoord, Victor F. Bense, Barret L. Kurylyk
Geochemical and mineralogical properties of Boquillas Shale geochemical reference material ShBOQ-1
Surface effects of sea-level rise (SLR) in permafrost regions are obvious where increasingly iceless seas erode and inundate coastlines. SLR also drives saltwater intrusion, but subsurface impacts on permafrost-bound coastlines are unseen and unclear due to limited field data and the absence of models that include salinity-dependent groundwater flow with solute exclusion and freeze-thaw dynamics. Here, we develop a numerical model with the aforementioned processes to investigate climate change impacts on coastal permafrost. We find that SLR drives lateral permafrost thaw due to depressed freezing temperatures from saltwater intrusion, whereas warming drives top-down thaw. Under high SLR and low warming scenarios, thaw driven by SLR exceeds warming-driven thaw when normalized to the influenced surface area. Results highlight an overlooked feedback mechanism between SLR and permafrost thaw with potential implications for coastal infrastructure, ocean-aquifer interactions, and carbon mobilization.
Released September 20, 2021 18:15 EST
2021, Fact Sheet 2021-3048
Justin E. Birdwell, Stephen A. Wilson
The ShBOQ-1 geochemical reference material is relevant to studies of the organic geochemistry and mineralogy of petroleum source rocks containing high concentrations of carbonate minerals and organic sulfur-rich, oil-prone marine organic matter. ShBOQ-1 is geochemically and mineralogically similar to the lower part of the Upper Cretaceous Eagle Ford Shale.
Integrating regional and local monitoring data and assessment tools to evaluate habitat conditions and inform river restoration
Released September 20, 2021 10:49 EST
2021, Ecological Indicators
Francine H. Mejia, Jason M Connor, Phil R Kaufmann, Christian E. Torgersen, Eric K Berntsen, Todd Andersen
RRestoring degraded rivers requires initial assessment of the fluvial landscape to identify stressors and riverine features that can be enhanced. We associated local-scale river habitat data collected using standardized national monitoring tools with modeled regional water temperature and flow data on mid-sized northwest U.S. rivers (30–60 m wide). We grouped these rivers according to quartiles of their modeled mean August water temperature and examined their physical habitat structure and flow. We then used principal components analysis to summarize the variation in several dimensions of physical habitat. We also compared local conditions in the Priest River, a river targeted for restoration of native salmonid habitat in northern Idaho, with those in other rivers of the region to infer potential drivers controlling water temperature. The warmest rivers had physical structure and fluvial characteristics typical of thermally degraded rivers, whereas the coldest rivers had higher mean summer flows and greater channel planform complexity. The Priest River sites had approximately twice as many deep residual pools (>50, >75, and >100 cm) and incision that averaged approximately twice that in the coldest rivers. Percentage fines and natural cover in the Priest were also more typical of the higher-temperature river groups. We found generally low instream cover and low levels of large wood both across the region and within the Priest River. Our approach enabled us to consider the local habitat conditions of a river in the context of other similarly sized rivers in the surrounding region. Understanding this context is important for identifying potential influences on river water temperature within the focal basin and for defining attainable goals for management and restoration of thermal and habitat conditions.
Development of regression equations for the estimation of the magnitude and frequency of floods at rural, unregulated gaged and ungaged streams in Puerto Rico through water year 2017
Released September 20, 2021 09:49 EST
2021, Scientific Investigations Report 2021-5062
Patrick J. Ryan, Anthony J. Gotvald, Cody L. Hazelbaker, Andrea G. Veilleux, Daniel M. Wagner
The methods of computation and estimates of the magnitude of flood flows were updated for the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent chance exceedance levels for 91 streamgages on the main island of Puerto Rico by using annual peak-flow data through 2017. Since the previous flood frequency study in 1994, the U.S. Geological Survey has collected additional peak flows at additional streamgages, and Puerto Rico has experienced numerous flood events. This updated study was performed using longer annual peak-flow datasets from more stations to provide more representative equations to predict flood flows. Screening criteria for these streamgages included 10 or more years of annual peak-flow data, unregulated flow, and less than 10 percent impervious drainage area.
The magnitude and frequency of floods at selected streamgages in Puerto Rico were estimated using updated methods outlined in Bulletin 17C. The new procedures include a regional skew analysis that incorporates Bayesian regression techniques, the Expected Moments Algorithm to better represent missing record and estimate parameters of the log-Pearson Type III distribution, and the Multiple Grubbs-Beck test for low outlier detection.
Regional regression equations were developed to estimate peak-flow statistics at ungaged locations by using selected basin and climatic characteristics as explanatory variables. These variables were determined from digital spatial datasets and geographic information systems by using the most recent data available. Ordinary least-squares regression techniques were used to filter the basin characteristics and determine two separate regions, region 1 (west) and region 2 (east), based on residuals. A generalized least-squares procedure was used to account for cross-correlation of sites and develop the final set of equations that have drainage area as the only explanatory variable. The average standard errors of prediction ranged from 18.7 to 46.7 percent in region 1 and 33.4 to 57.6 percent in region 2 for all annual exceedance probabilities (AEPs) examined. The updated statistics showed a greater accuracy of prediction when compared to those from the previous study using drainage area as the only explanatory variable for all AEPs examined in region 1 and the 0.01 and 0.002 AEP flows for region 2. When compared to equations developed in the previous study that have drainage area, mean annual rainfall, and (or) depth-to-rock as explanatory variables, the updated statistics show a greater accuracy of prediction in region 1 at AEP flows of 0.02 and lower (that is, higher flows). Those developed for region 2 do not show a greater accuracy of prediction for any AEP flows when compared to the equations having multiple explanatory variables in the previous study.
The calculated regression equations, basin characteristics, and at-site statistics will be incorporated into the U.S. Geological Survey web application, StreamStats (https://streamstats.usgs.gov/ss/). This application allows users to select a location on a stream, whether gaged or ungaged, to obtain estimates of basin characteristics and flow statistics.
A comparison of methods for the long-term harness-based attachment of radio-transmitters to juvenile Japanese quail (Coturnix japonica)
Released September 20, 2021 07:50 EST
2021, Animal Biotelemetry (9)
Evan J Buck, Jeffery D Sullivan, Cody M. Kent, Jennifer M. Mullinax, Diann Prosser
While the period from fledging through first breeding for waterbird species such as terns (e.g., genus Sterna, Sternula) is of great interest to researchers and conservationists, this period remains understudied due in large part to the difficulty of marking growing juveniles with radio transmitters that remain attached for extended periods.
In an effort to facilitate such research, we examined the impact of various combinations of harness types (backpack, leg-loop, and 3D-printed harnesses), harness materials (Automotive ribbon, Elastic cord, and PFTE ribbon), and transmitter types (center-weighted and rear-weighted) on a surrogate for juvenile terns, 28-day-old Japanese quail (Coturnix japonica; selected due to similarities in adult mass and downy feathering of juveniles), in a 30-day experiment. We monitored for abrasion at points of contact and tag gap issues via daily exams while also recording mass and wing cord as indices of growth. This study was designed to serve as an initial examination of the impacts of marking on the growth and development of young birds and does not account for any impacts of tags on movement or behavior.
While we found that treatment (the specific combination of the transmitter type, harness type, and harness material) had no impact on bird growth relative to unmarked control birds (P ≥ 0.05), we did observe differences in abrasion and tag gap between treatments (P ≤ 0.05). Our results suggest that leg-loop harnesses constructed from elastic cord and backpack harnesses from PFTE ribbon are suitable options for long-term attachment to growing juveniles. Conversely, we found that automotive ribbon led to extensive abrasion with these small-bodied birds, and that elastic cord induced blisters when used to make a backpack harness.
While these results indicate that long-term tagging of juvenile birds is possible with limited impacts on growth, this work does not preclude the need for small-scale studies with individual species. Instead, we hope this provides an informed starting point for further exploration of this topic.
Development of a screening tool to examine lake and reservoir susceptibility to eutrophication in selected watersheds of the eastern and southeastern United States
Released September 20, 2021 06:57 EST
2021, Scientific Investigations Report 2021-5075
W. Reed Green, Anne B. Hoos, Alan E. Wilson, Elizabeth N. Heal
This report describes a new screening tool to examine lake and reservoir susceptibility to eutrophication in selected watersheds of the eastern and southeastern United States using estimated nutrient loading and flushing rates with measures of waterbody morphometry. To that end, the report documents the compiled data and methods (R-script) used to categorize waterbodies by Carlson’s Trophic State Index. Assessments were completed for 232 lakes and reservoirs having a surface area greater than or equal to 0.1 square kilometer in watersheds that drain to the Atlantic and eastern Gulf of Mexico coasts of the United States and in watersheds within the Tennessee River Basin. Waterbodies were categorized by type—natural lakes, headwater reservoirs, and downstream reservoirs—and were assessed independently. Recursive partitioning and the model-based boosting routine were used to create four-node regression trees to group waterbodies into five endpoints from low-to-high measures of Secchi depth, and concentrations of chlorophyll a and microcystin according to shared nutrient loading, flushing rate, and morphometric characteristics. Trophic state designations were assigned based on the average value within each of the five endpoints. An application (procedure) is provided using the tool to examine the susceptibility of a given waterbody of interest to eutrophication. Results of this study can aid water-resource managers in prioritizing lake and reservoir protection and restoration efforts based on the susceptibility of these waterbodies to eutrophication relative to nutrient loading, flushing rate, and morphometric characteristics.