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USGS2016

U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2015 annual report

This is the eighth annual report highlighting U.S. Geological Survey (USGS) science and decision-support activities conducted for the Wyoming Landscape Conservation Initiative (WLCI). The activities address specific management needs identified by WLCI partner agencies. In 2015, USGS scientists continued 24 WLCI projects in 5 categories: (1) acquiring and analyzing resource-condition data to form a foundation for understanding and monitoring landscape conditions and projecting changes; (2) using new technologies to improve the scope and accuracy of landscape-scale monitoring and assessments, and applying them to monitor indicators of ecosystem conditions and the effectiveness of on-the-ground habitat projects; (3) conducting research to elucidate the mechanisms that drive wildlife and habitat responses to changing land uses; (4) managing and making accessible the large number of databases, maps, and other products being developed; and (5) coordinating efforts among WLCI partners, helping them to use USGS-developed decision-support tools, and integrating WLCI outcomes with future habitat enhancement and research projects. Of the 24 projects, 21 were ongoing, including those that entered new phases or more in-depth lines of inquiry, 2 were new, and 1 was completed. A highlight of 2015 was the WLCI science conference sponsored by the USGS, Bureau of Land Management, and National Park Service in coordination with the Wyoming chapter of The Wildlife Society. Of 260 participants, 41 were USGS professionals representing 13 USGS science centers, field offices, and Cooperative Wildlife Research Units. Major themes of USGS presentations included using new technologies for developing more efficient research protocols for modeling and monitoring natural resources, researching effects of energy development and other land uses on wildlife species and habitats of concern, and modeling species distributions, population trends, habitat use, and effects of land-use changes. There was also a special session on the effectiveness of Wyoming’s Sage-Grouse Executive Order. Combined, USGS presentations provided WLCI partners with a wealth of information and conservation tools. The project completed in 2015 yielded an index of important agricultural lands in the WLCI region. The index improves upon existing measures of agricultural productivity and provides planners and managers with additional values to consider when making decisions about land use and conservation actions. The two new projects include an analysis of satellite imagery to quantify sagebrush productivity and mortality, and an evaluation of how groundwater and small streams interact in the upper Green River Basin. Initiated in response to concern among WLCI partners that large areas of sagebrush appear to have died recently, the sagebrush study objectives are to assess effects of these mortality events on overall sagebrush ecosystem productivity, evaluate the feasibility of using satellite imagery to detect patterns in sagebrush mortality over time, and identify factors driving these mortality events. The groundwater-streamflow interaction study is being conducted by hydrologists and fish ecologists to better understand how groundwater-streamflow interactions are affected by energy-resource development and how native fish communities are affected by these factors. Expected outcomes of both new projects will provide WLCI partners with additional information and decision-support tools. Highlights of ongoing science foundation activities included simulations of nine alternative build-out scenarios for oil and gas development and an associated online fact sheet that explains how the simulations were conducted, with an applied example for the Atlantic Rim. Also completed in 2015 was an update of the USGS online inventory of mineral resources data, and publication of a USGS uranium resource survey for the WLCI region. Combined, the outcomes of this work provide decisionmakers and managers with important baseline information for existing and (or) future planning and monitoring efforts. Terrestrial monitoring activities in 2015 emphasized the use of satellite data in combination with other technologies and field data to monitor, assess, and (or) forecast distribution patterns and (or) trends in sagebrush ecosystems, seasonal and migration stopover habitats used by mule deer and elk, and semi-arid aspen woodlands. Several professional papers detailing new monitoring models and results have been published. Combined, this and related work will help managers understand distribution patterns and trends among priority habitats, identify areas in need of restoration or conservation, and monitor the effectiveness of habitat-management actions. Aquatic monitoring activities entailed not only the new groundwater-streamflow interaction study already mentioned, but also continued monitoring with streamgages paired with nearby wells in the Green River Basin to assess groundwater effects on streamflow and surface water temperatures. A map that portrays groundwater levels and general direction of flow in the Green River Basin was published as well . Overall, outcomes of USGS hydrological research and monitoring will inform WLCI partners about water resources in the WLCI region and help to explain fish-community responses to energy-resource development. In 2015, USGS terrestrial wildlife ecologists continued to make crucial strides towards better understanding wildlife species responses to energy-resource development and other land-use changes. This body of research includes six taxa that require or heavily depend on sagebrush habitats: sage-grouse, pygmy rabbits, 3 songbird species, and mule deer. Native fish communities are also being evaluated. Approaches include modeling and mapping wildlife species distributions, abundances, and trends; using satellite and other technologies to track wildlife seasonal movements; conducting successive phases of research that build on the knowledge gained through prior phases to reveal the specific factors or thresholds that drive population- or individual-level responses to changes; and conducting population viability analyses. Additionally, wildlife habitat association models for pygmy rabbit and sage-grouse were combined with the oil and gas build-out scenarios to project species responses to alternative energy development scenarios. Outcomes of the wildlife response research are helping decisionmakers and managers identify specific factors that contribute to species population trends, the potential for spatial overlap between important wildlife habitats and proposed energy-resource development, locations of priority habitats for restoration and conservation, and more. Data and WLCI Web site management highlights of 2015 included not only ongoing software upgrades, but also an update of the datasets displayed in two of the online products developed for the WLCI effort: (1) a map of 15,532 oil and natural gas well pad scars and other features associated with oil and gas extraction, and (2) a map of oil and gas, oil shale, uranium, and solar energy production, both for southwestern Wyoming. In addition, a map viewer was developed for a previously published map of coal and wind production in relation to sage-grouse distribution and core management areas in southwestern Wyoming. Combined, these maps place valuable decision-support tools in the hands of WLCI partners. The USGS coordination efforts on behalf of the WLCI in 2015 included significant work on planning and executing the WLCI science conference. They also included ongoing efforts to support Local Project Development Teams and the WLCI Coordination Team (CT) with developing conservation priorities and strategies, identifying priority areas for future conservation actions, supporting the evaluation and ranking of conservation projects, and evaluating the ways in which proposed habitat projects relate to WLCI priorities. In 2015, the USGS also assisted the WLCI CT with updating the WLCI Conservation Action Plan.

Wyoming↗
USGS2005

Factors influencing mercury in freshwater surface sediments of northeastern North America

We report on an inventory and analysis of sediment mercury (Hg) concentrations from 579 sites across northeastern North America. Sediment Hg concentrations ranged from the limit of detection ca. 0.01-3.7 ??g g -1 (dry weight, d.w.), and the average concentration was 0.19 ??g g-1 (d.w.) Sediment methylmercury concentrations ranged from 0.15 to 21 ng g-1 (d.w.) and the mean concentration was 3.83 ng g -1 (d.w.). Total Hg concentrations (HgT) were greatest in lakes > reservoirs > rivers, although the proportion of Hg as methylmercury showed an inverse pattern. Total Hg was weakly and positively correlated with the sediment organic matter and percent of watershed as forested land, and weakly and negatively correlated with sediment solids content, drainage area, and agricultural land. Sediment methylmercury concentrations were weakly and positively correlated to wetland area, and weakly and negatively correlated to drainage area. Methylmercury, expressed as a percentage of HgT was positively correlated to agricultural land area. For sites with co-located sediment and fish-tissue sampling results, there was no relationship between sediment Hg and fish-tissue Hg. Finally, our data indicate that at least 44% of waters across the region have sediment HgT concentrations in excess of Canadian and United States minimum sediment contaminant guidelines for the protection of aquatic biota. ?? 2005 Springer Science+Business Media, Inc.

Ecotoxicology↗
USGS2025

Exploring the news media and scientific conversations around water quality in a water-rich basin of the United States

Community concerns about water availability vary depending on local economic, regulatory, environmental, and ecological considerations. In water-rich basins, water quality is often the focus of community concerns. As such, understanding community priorities in the context of water quality is crucial for informing scientists working in water-rich basins. In this work, we compiled over 6,500 local news articles (public discourse) and 190 scientific abstracts (scientific discourse) related to water-quality issues in the water-rich Illinois River Basin (ILRB) published between 2018 and 2022. We applied a Structural Topic Model (STM) to identify key water-quality topics within both datasets and explore the variability of newspaper topics geographically across the basin. Prevalent topics in both the public (local news articles) and scientific (abstracts) discourses were agriculture, drinking water quality, PFAS (per- and polyfluoroalkyl substances), and river ecosystem/fish. Topics exclusive to public discourse included water infrastructure, community development, and public water supply, while the scientific discourse focused more heavily on a wider range of agricultural issues. Furthermore, the public discourse varied geographically across the basin. Some topics are correlated with land use or urban/rural divides within the basin, and the frequency of many topics clearly varied across state (political) boundaries. Understanding and quantifying public and scientific discourses related to water-quality are important for scientists and water managers working in the basin to improve communication of critical science to the public.

Illinois, Indiana, Michigan, Wisconsin↗
USGS1995

Non-native animals on public lands

Non-native plants and animals have become part of our surroundings, in cities, agricultural areas, and wildlands. While there are many beneficial purposes for non-native animals, such as for food and sport hunting and as agricultural animals, the introduction of some has had major negative economic consequences (Palmer 1899), and adverse effects on native wildlife, plants, and habitats. The British ecologist Charles Elton, in a major review of introduced species, described the increasing number of invasions as constituting "one of the great historical convulsions in the world's flora and fauna" (Elton 1958, p. 31). Non-native species are significant problems on large areas of state and federal public lands, and areas set aside to protect native plant and animal communities are not immune to such harm. Science and conservation journals have devoted entire issues to the threats posed by non-native plants and animals in nature reserves (e.g., Usher et al. 1988). In a compilation of threats to U.S. national parks, non-native plants and animals were the most often reported threat, and were reported by the most areas; feral cats ( Felis catus ), feral dogs ( Canis familiaris ), and wild pigs ( Sus scrofa ) were the non-native animals cited most often (NPCA 1977). Non-native species present serious threats, but at the same time, coordinated efforts on public lands offer the best possibility for controlling some harmful non-native species, and protecting both native plant and animal communities and human interests and needs. We compiled information on non-native animals on public and private land-management areas by conducting a mail survey to assess their occurrence and management status in land-management areas. Survey results represent contributions from 937 national parks, national forests, national wildlife refuges, Bureau of Land Management field areas, and state and private land-management areas. The results reflect those species that land managers considered of greatest concern, and their general distribution on public lands. Non-native invertebrate animals, particularly forest insects and agricultural pests, cause severe economic and environmental damage as well (OTA 1993), but were not the focus of this survey.

Book chapter↗
USGS2011

Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil

Transport of Cryptosporidium parvum oocysts and microspheres in two disparate (a clay- and Fe-rich, volcanic and a temperate, humic) agricultural soils were studied in the presence and absence of 100 mg L –1 of sodium dodecyl benzene sulfonate (SDBS), and Suwannee River Humic Acid (SRHA) at pH 5.0–6.0. Transport of carboxylate-modified, 1.8 μm microspheres in soil columns was highly sensitive to the nature of the dissolved organic carbon (DOC), whereas oocysts transport was more affected by soil mineralogy. SDBS increased transport of microspheres from 48% to 87% through the tropical soil and from 43% to 93% in temperate soil. In contrast, SRHA reduced transport of microspheres from 48% to 28% in tropical soil and from 43% to 16% in temperate soil. SDBS also increased oocysts transport through the temperate soil 5-fold, whereas no oocyst transport was detected in tropical soil. SRHA had only a nominal effect in increasing oocysts transport in tropical soil, but caused a 6-fold increase in transport through the temperate soil. Amendments of only 4 mg L –1 SRHA and SDBS decreased oocyst hydrophobicity from 66% to 20% and from 66% to 5%, respectively. However, SDBS increased microsphere hydrophobicity from 16% to 33%. Soil fines, which includes clays, and SRHA, both caused the oocysts zeta potential (ζ) to become more negative, but caused the highly hydrophilic microspheres to become less negatively charged. The disparate behaviors of the two colloids in the presence of an ionic surfactant and natural organic matter suggest that microspheres may not be suitable surrogates for oocysts in certain types of soils. These results indicate that whether or not DOC inhibits or promotes transport of oocysts and microspheres in agricultural soils and by how much, depends not only on the surface characteristics of the colloid, but the nature of the DOC and the soil mineralogy.

Environmental Science & Technology↗
USGS2008

Methods of Data Collection, Sample Processing, and Data Analysis for Edge-of-Field, Streamgaging, Subsurface-Tile, and Meteorological Stations at Discovery Farms and Pioneer Farm in Wisconsin, 2001-7

The University of Wisconsin (UW)-Madison Discovery Farms (Discovery Farms) and UW-Platteville Pioneer Farm (Pioneer Farm) programs were created in 2000 to help Wisconsin farmers meet environmental and economic challenges. As a partner with each program, and in cooperation with the Wisconsin Department of Natural Resources and the Sand County Foundation, the U.S. Geological Survey (USGS) Wisconsin Water Science Center (WWSC) installed, maintained, and operated equipment to collect water-quantity and water-quality data from 25 edge-offield, 6 streamgaging, and 5 subsurface-tile stations at 7 Discovery Farms and Pioneer Farm. The farms are located in the southern half of Wisconsin and represent a variety of landscape settings and crop- and animal-production enterprises common to Wisconsin agriculture. Meteorological stations were established at most farms to measure precipitation, wind speed and direction, air and soil temperature (in profile), relative humidity, solar radiation, and soil moisture (in profile). Data collection began in September 2001 and is continuing through the present (2008). This report describes methods used by USGS WWSC personnel to collect, process, and analyze water-quantity, water-quality, and meteorological data for edge-of-field, streamgaging, subsurface-tile, and meteorological stations at Discovery Farms and Pioneer Farm from September 2001 through October 2007. Information presented includes equipment used; event-monitoring and samplecollection procedures; station maintenance; sample handling and processing procedures; water-quantity, waterquality, and precipitation data analyses; and procedures for determining estimated constituent concentrations for unsampled runoff events.

Open-File Report↗
USGS2017

Using object-based image analysis to conduct high-resolution conifer extraction at regional spatial scales

The distribution and abundance of pinyon ( Pinus monophylla ) and juniper ( Juniperus osteosperma, J. occidentalis ) trees (hereinafter, "pinyon-juniper") in sagebrush ( Artemisia spp.) ecosystems of the Great Basin in the Western United States has increased substantially since the late 1800s. Distributional expansion and infill of pinyon-juniper into sagebrush ecosystems threatens the ecological function and economic viability of these ecosystems within the Great Basin, and is now a major contemporary challenge facing land and wildlife managers. Particularly, pinyon-juniper encroachment into intact sagebrush ecosystems has been identified as a primary threat facing populations of greater sage-grouse ( Centrocercus urophasianus ; hereinafter, "sage-grouse"), which is a sagebrush obligate species. Even seemingly innocuous scatterings of isolated pinyon-juniper in an otherwise intact sagebrush landscape can negatively affect survival and reproduction of sage-grouse. Therefore, accurate and high-resolution maps of pinyon-juniper distribution and abundance (indexed by canopy cover) across broad geographic extents would help guide land management decisions that better target areas for pinyon-juniper removal projects (for example, fuel reduction, habitat improvement for sage-grouse, and other sagebrush species) and facilitate science that further quantifies ecological effects of pinyon-juniper encroachment on sage-grouse populations and sagebrush ecosystem processes . Hence, we mapped pinyon-juniper (referred to as conifers for actual mapping) at a 1 × 1-meter (m) high resolution across the entire range of previously mapped sage-grouse habitat in Nevada and northeastern California. We used digital orthophoto quad tiles from National Agriculture Imagery Program (2010, 2013) as base imagery, and then classified conifers using automated feature extraction methodology with the program Feature Analyst ™ . This method relies on machine learning algorithms that extract features from imagery based on their spectral and spatial signatures. We classified conifers in 6,230 tiles and then tested for errors of omission and commission using confusion matrices. Accuracy ranged from 79.1 to 96.8, with an overall accuracy of 84.3 percent across all mapped areas. An estimated accuracy coefficient (kappa) indicated substantial to nearly perfect agreement, which varied across mapped areas. For this mapping process across the entire mapping extent, four sets of products are available at https://doi.org/10.5066/F7348HVC , including (1) a shapefile representing accuracy results linked to mapping subunits; (2) binary rasters representing conifer presence or absence at a 1 × 1 m resolution; (3) a 30 × 30 m resolution raster representing percentages of conifer canopy cover within each cell from 0 to 100; and (4) 1 × 1 m resolution canopy cover classification rasters derived from a 50-m-radius moving window analysis. The latter two products can be reclassified in a geographic information system (GIS) into user-specified bins to meet different objectives, which include approximations for phases of encroachment. These products complement, and in some cases improve upon, existing conifer maps in the Western United States, and will help facilitate sage-grouse habitat management and sagebrush ecosystem restoration.

California, Nevada↗
USGS2021

Evidence that watershed nutrient management practices effectively reduce estrogens in environmental waters

We evaluate the impacts of different nutrient management strategies on the potential for co-managing estrogens and nutrients in environmental waters of the Potomac watershed of the Chesapeake Bay. These potential co-management approaches represent agricultural and urban runoff, wastewater treatment plant effluent, and combined sewer overflow replacements. Twelve estrogenic compounds and their metabolites were analysed by gas chromatography–mass spectrometry. Estrogenic activity (E 2 Eq) was measured by in vitro bioassay. We detected estrone E 1 (0.05–6.97 ng L −1 ) and estriol E 3 (below detection-8.13 ng L −1 ) and one conjugated estrogen (estrone-3-sulfate E 1 -3S; below detection-8.13 ng L −1 ). E 1 was widely distributed and positively correlated with E 2 Eq, water temperature, and dissolved organic carbon (DOC). Among nonpoint sources, E 2 Eq, and concentrations of E 1 , soluble reactive phosphorus (SRP) and total dissolved nitrogen (TDN) decreased by 51–61%, 77–82%, 62–64%, 4–16% in restored urban and agricultural streams with best management practices (BMPs) relative to unrestored streams without BMPs. In a wastewater treatment plant (Blue Plains WWTP), >94% of E 1 , E 1 -3S, E 3 , E 2 Eq and TDN were removed while SRP increased by 305% during nitrification/denitrification as a part of advanced wastewater treatment. Consequently, E 1 and TDN concentrations in WWTP effluents were comparable or even lower than those observed in the receiving stream or river waters, and the effects of wastewater discharges on downstream E 1 and TDN concentrations were minor. Highest E 2 Eq value and concentrations of E1, E3, and TDN were detected in combined sewer overflow (CSO). This study suggests that WWTP upgrades with biological nutrient removal, CSO management, and certain agricultural and urban BMPs for nutrient controls have the potential to remove estrogens from point and nonpoint sources along with other contaminants in streams and rivers.

Maryland↗
USGS2000

Pesticides in the atmosphere of the Mississippi River Valley, part I: Rain

Weekly composite rainfall samples were collected in three paired urban and agricultural regions of the Midwestern United States and along the Mississippi River during April–September 1995. The paired sampling sites were located in Mississippi, Iowa, and Minnesota. A background site, removed from dense urban and agriculture areas, was located near Lake Superior in Michigan. Herbicides were the predominant type of pesticide detected at every site. Each sample was analyzed for 47 compounds and 23 of 26 herbicides, 13 of 18 insecticides, and three of three related transformation products were detected in one or more sample from each paired site. The detection frequency of herbicides and insecticides were nearly equivalent at the paired Iowa and Minnesota sites. In Mississippi, herbicides were detected more frequently at the agricultural site and insecticides were detected more frequently at the urban site. The highest total wet depositional amounts (μg pesticide/m 2 per season) occurred at the agricultural sites in Mississippi (1980 μg/m 2 ) and Iowa (490 μg/m 2 ) and at the urban site in Iowa (696 μg/m 2 ). Herbicides accounted for the majority of the wet depositional loading at the Iowa and Minnesota sites, but methyl parathion (1740 μg/m 2 ) was the dominant compound contributing to the total loading at the agricultural site in Mississippi. Atrazine, CIAT (a transformation product of atrazine and propazine) and dacthal were detected most frequently (76, 53, and 53%, respectively) at the background site indicating their propensity for long-range atmospheric transport.

Mississippi River Valley↗
USGS2008

Methods and sources of data used to develop selected water-quality indicators for streams and ground water for EPA's 2007 Report on the Environment: Science report

The U.S. Geological Survey (USGS) was one of numerous governmental agencies, private organizations, and the academic community that provided data and interpretations for the U.S. Environmental Protection Agency’s (USEPA) 2007 Report on the Environment: Science Report . This report documents the sources of data and methods used to develop selected water–quality indicators for the 2007 edition of the report compiled by USEPA. Stream and ground–water–quality data collected nationally in a consistent manner as part of the USGS’s National Water–Quality Assessment Program (NAWQA) were provided for several water–quality indicators, including Nitrogen and Phosphorus in Streams in Agricultural Watersheds; Pesticides in Streams in Agricultural Watersheds; and Nitrate and Pesticides in Shallow Ground Water in Agricultural Watersheds . In addition, the USGS provided nitrate (nitrate plus nitrite) and phosphorus riverine load estimates calculated from water–quality and streamflow data collected as part of its National Stream Water Quality Accounting Network (NASQAN) and its Federal–State Cooperative Program for the Nitrogen and Phosphorus Discharge from Large Rivers indicator.

Open-File Report↗
USGS2019

Potentiometric surface of the Mississippi River Valley alluvial aquifer, spring 2016

A potentiometric surface map for spring 2016 was created for the Mississippi River Valley alluvial (MRVA) aquifer using selected available groundwater-altitude data from wells and surface-water-altitude data from streamgages. Most of the wells were measured annually or one time after installation, but some wells were measured more than one time or continually; streamgages are typically operated continuously. Personnel from the Arkansas Natural Resources Commission, Arkansas Department of Health, Arkansas Geological Survey, Illinois Department of Agriculture, Illinois State Water Survey, Louisiana Department of Natural Resources, Louisiana Department of Transportation and Development, Mississippi Department of Environmental Quality, Yazoo Mississippi Delta Joint Water Management District, U.S. Department of Agriculture–Natural Resources Conservation Service, and the U.S. Geological Survey (USGS) routinely collect groundwater data from wells screened in the MRVA aquifer. The USGS and the U.S. Army Corps of Engineers routinely collect data on river stage and discharge for the rivers overlying the MRVA aquifer. The potentiometric surface map for 2016 was created using existing data as part of the USGS Water Availability and Use Science Program to support investigations that characterize the MRVA aquifer. Sufficient groundwater-altitude data were available to create a potentiometric-surface map for spring 2016 for about 81 percent of the aquifer area. The potentiometric contours ranged from 10 to 340 feet. The regional direction of groundwater flow in the MRVA aquifer was generally towards the south-southwest, except in areas of groundwater-altitude depressions, where groundwater flows into the depressions, and near rivers, where groundwater flow generally parallels the flow in the rivers. There are large depressions in the potentiometric surface of the MRVA aquifer in the lower half of the Cache region and in most of the Grand Prairie and Delta regions.

Arkansas, Illinois, Kentucky, Louisiana, Mississip↗
USGS2006

Does anthropogenic nitrogen enrichment increase organic nitrogen concentrations in runoff from forested and human-dominated watersheds?

Although the effects of anthropogenic nitrogen (N) inputs on the dynamics of inorganic N in watersheds have been studied extensively, "the influence of N enrichment on organic N loss" is not as well understood. We compiled and synthesized data on surface water N concentrations from 348 forested and human-dominated watersheds with a range of N loads (from less than 100 to 7,100 kg N km-2 y-1) to evaluate the effects of N loading via atmospheric deposition, fertilization, and wastewater on dissolved organic N (DON) concentrations. Our results indicate that, on average, DON accounts for half of the total dissolved N (TDN) concentrations from forested watersheds, but it accounts for a smaller fraction of TDN in runoff from urban and agricultural watersheds with higher N loading. A significant but weak correlation (r 2 = 0.06) suggests that N loading has little influence on DON concentrations in forested watersheds. This result contrasts with observations from some plot-scale N fertilization studies and suggests that variability in watershed characteristics and climate among forested watersheds may be a more important control on DON losses than N loading from atmospheric sources. Mean DON concentrations were positively correlated, however, with N load across the entire land-use gradient (r 2 = 0.37, P < 0.01), with the highest concentrations found in agricultural and urban watersheds. We hypothesize that both direct contributions of DON from wastewater and agricultural amendments and indirect transformations of inorganic N to organic N represent important sources of DON to surface waters in human-dominated watersheds. We conclude that DON is an important component of N loss in surface waters draining forested and human-dominated watersheds and suggest several research priorities that may be useful in elucidating the role of N enrichment in watershed DON dynamics. ?? 2006 Springer Science+Business Media, Inc.

Ecosystems↗
USGS2019

History and sources of co-occurring pesticides in an abstraction well unravelled by age distributions of depth specific groundwater samples

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse sources and different contaminants may have different sources even in a single groundwater well, making these questions complicated to answer. Age dating of groundwater has been used to reconstruct contaminant travel times to wells; however, critics have highlighted that groundwater flow is often complex with mixing of groundwater of different ages. In drinking water wells, where water is typically abstracted from a large depth interval, such mixing is even more problematic. We present a way to overcome some of the obstacles in identifying the source and age of contaminants in drinking water wells by combining depth-specific sampling with age tracer modeling, particle tracking simulations, geological characterization, and contaminant properties. This multitool approach was applied to a drinking water well, where bentazon and dichlorprop contamination was found to have different pollutant sources and release histories, even though both pesticides can be associated with the same land use. Bentazon was derived from recent application to a golf course, while dichlorprop was derived from agricultural use more than 30 years ago. The advantages, limitations, and pitfalls of the proposed course of action are then further discussed.

Environmental Science & Technology↗
USGS1996

Biomass patterns in seagrass meadows of the Laguna Madre, Texas

The Laguna Madre of Texas supports the most extensive seagrass meadows in the western Gulf of Mexico, In 1988 seagrasses covered 730 km 2 or about three-quarters of the embayment. Halodule wrightii dominated the entire upper laguna, and total biomass was quite uniform near 160 g˙m -2 throughout. Four species shared dominance in the lower laguna. Where present mean biomass of Thalassia testudinum was 373 g˙m -2 ; Syringodium filiforme , 138 g˙m -2 ; Halodule wrightii , 78 g˙m -2 ; and Halophila engelmannii , 6 g˙m -2 . Macroalgae were widespread, at 71 g˙m -2 where present. Halodule wrightii was dominant and biomass was low on sand flats of the barrier island separating the laguna from the gulf. Halophila engelmannii was limited to the deep edges of meadows. Biomass >300 g˙m -2 was limited to one extensive T. testudinum meadow at the south end of the laguna at all vegetated depths and two small areas with S. filiforme dominant at intermediate depths. Laguna Madre was similar in biomass to the two regions of extensive development of seagrasses in the eastern gulf: the Big Bend region of Florida (Iverson and Bittaker, 1986) and Florida Bay (Iverson and Bittaker, 1986; Zieman, et al., 1989). The laguna differed from the eastern gulf sites in more turbid waters and much shallower maximum depths of occurrence of seagrasses (<2 m compared to 8–11 m), higher contribution of H. wrightii to system-wide biomass (although H. wrightii 's share has rapidly diminished in Laguna Madre as it has been displaced by S. filiforme and T. testudinum [Quammen and Onuf, 1993]), and much higher macroalgal biomass (limited to the section of the lower laguna receiving agricultural inflows). Similarities in the environments of Laguna Madre and inner Florida Bay suggest that, if cover and biomass of Thalassia continue to increase, the laguna may become vulnerable to mass mortalities as are now occurring in Florida Bay.

Texas↗
USGS2015

Ahead of his time: Jacob Lipman's 1930 estimate of atmospheric sulfur deposition for the conterminous United States

A 1936 New Jersey Agricultural Experiment Station Bulletin provided an early quantitative assessment of atmospheric deposition of sulfur for the United States that has been compared in this study with more recent assessments. In the early 20th century, anthropogenic sulfur additions from the atmosphere to the soil by the combustion of fossil fuels were viewed as part of the requisite nutrient supply of crops. Jacob G. Lipman, the founding editor of Soil Science, and his team at Rutgers University, made an inventory of such additions to soils of the conterminous United States during the economic depression of the 1930s as part of a federally funded project looking at nutrient balances in soils. Lipman's team gathered data compiled by the US Bureau of Mines on coal and other fuel consumption by state and calculated the corresponding amounts of sulfur emitted. Their work pioneered a method of assessment that became the norm in the 1970s to 1980s&mdash;when acid rain emerged as a national issue. Lipman's estimate of atmospheric sulfur deposition in the 1930 is in reasonable agreement with recent historic reconstructions.

Soil Science↗
USGS2012

Estimated water requirements for gold heap-leach operations

This report provides a perspective on the amount of water necessary for conventional gold heap-leach operations. Water is required for drilling and dust suppression during mining, for agglomeration and as leachate during ore processing, to support the workforce (requires water in potable form and for sanitation), for minesite reclamation, and to compensate for water lost to evaporation and leakage. Maintaining an adequate water balance is especially critical in areas where surface and groundwater are difficult to acquire because of unfavorable climatic conditions [arid conditions and (or) a high evaporation rate]; where there is competition with other uses, such as for agriculture, industry, and use by municipalities; and where compliance with regulatory requirements may restrict water usage. Estimating the water consumption of heap-leach operations requires an understanding of the heap-leach process itself. The task is fairly complex because, although they all share some common features, each gold heap-leach operation is unique. Also, estimating the water consumption requires a synthesis of several fields of science, including chemistry, ecology, geology, hydrology, and meteorology, as well as consideration of economic factors.

Open-File Report↗
USGS2025

Practitioners’ perceived risks to biodiversity from renewable energy expansion through 2050

Large-scale (e.g., > 1 megawatt capacity) wind and solar energy (hereafter, LSWS) developments are increasing to aid decarbonization. However, LSWS can also negatively affect biodiversity. Planners and other interested parties’ perceptions about the impact of LSWS on biodiversity will thus affect how trade-offs are managed during planning and buildout. We present a survey of professionals (n=116) working at the intersection of LSWS and biodiversity protection across the United States concerning: (1) perceived environmental impacts from LSWS expansion; and (2) how these impacts compare to other land-use and land-cover change drivers. We find that practitioners perceive LSWS to impact biodiversity negatively but less so than other land-cover change drivers, including fossil fuels and agriculture. This highlights the need for increased attention to the role of practitioners in advancing renewable energy and biodiversity conservation.

Humanities and Social Sciences Communications↗
USGS2001

Large carbon isotope fractionation associated with oxidation of methyl halides by methylotrophic bacteria

The largest biological fractionations of stable carbon isotopes observed in nature occur during production of methane by methanogenic archaea. These fractionations result in substantial (as much as ≈70‰) shifts in δ 13 C relative to the initial substrate. We now report that a stable carbon isotopic fractionation of comparable magnitude (up to 70‰) occurs during oxidation of methyl halides by methylotrophic bacteria. We have demonstrated biological fractionation with whole cells of three methylotrophs (strain IMB-1, strain CC495, and strain MB2) and, to a lesser extent, with the purified cobalamin-dependent methyltransferase enzyme obtained from strain CC495. Thus, the genetic similarities recently reported between methylotrophs, and methanogens with respect to their pathways for C 1 -unit metabolism are also reflected in the carbon isotopic fractionations achieved by these organisms. We found that only part of the observed fractionation of carbon isotopes could be accounted for by the activity of the corrinoid methyltransferase enzyme, suggesting fractionation by enzymes further along the degradation pathway. These observations are of potential biogeochemical significance in the application of stable carbon isotope ratios to constrain the tropospheric budgets for the ozone-depleting halocarbons, methyl bromide and methyl chloride. Methyl bromide (MeBr) and methyl chloride (MeCl) are, respectively, the most abundant volatile bromo- and chlorocarbons in the troposphere and are major contributors to stratospheric ozone destruction (1). Both compounds have natural and human-influenced sources and a predominant sink by reaction with OH in the troposphere (2–4). MeBr also has a bacterial soil sink (5) that represents about 20% of the estimated total removal from the troposphere, and it is likely that a soil sink of similar magnitude exists for MeCl (6). Hence, if an isotopic fractionation is associated with the soil sink, it will influence the isotopic compositions of MeBr and MeCl in the lower atmosphere (7). The δ 13 C value of industrially produced MeBr ranges between −43.5‰ and −66.4‰ (7), but δ 13 C values of tropospheric MeBr and natural sources are not yet known. The δ 13 C of atmospheric MeCl has been measured from −22‰ to −45‰ (8, 9). If carbon isotope ratios are to be used to constrain the budgets of these methyl halides, it is essential to determine the extent of carbon isotope fractionation that occurs during biological degradation of these compounds. Methylotrophic bacteria use C 1 compounds, which are simple organic molecules that contain no carbon–carbon bonds. Strains IMB-1, CC495, and MB2 are as-yet-unnamed facultative methylotrophs isolated from agricultural soil, woodland leaf litter, and coastal seawater, respectively (10–13), environments where methyl halides are produced. They are members of the α subgroup of the Proteobacteria . On the basis of 16S rRNA gene sequences, strains IMB-1 and CC495 show some phylogenetic alignment with the genus Rhizobium (10, 11) and are very closely related to the new genus Pseudoaminobacte r (I. McDonald, personal communication). Strain MB2 aligns within the Ruegeria clade [J. K. Schaefer, K. D. Goodwin, I. R. McDonald, J. C. Murrell and R.S.O., unpublished work]. All of these aerobic bacteria are methylotrophs in that they can grow by using MeBr or MeCl as their sole carbon source, but they do not metabolize methane. They oxidize MeBr, MeCl, and methyl iodide (MeI) to CO 2 . Soil bacteria are known to consume MeBr at the ambient tropospheric mixing ratio of around 10 parts per trillion by volume (5). Preliminary experiments with strain IMB-1 indicate that it can oxidize MeBr at these mixing ratios** and is therefore likely to be characteristic of bacteria associated with MeBr uptake by soils. We examined δ 13 C of MeCl, MeBr, and MeI during oxidation by whole-cell suspensions of IMB-1 and CC495 and also the change in δ 13 C values of the three methyl halides during oxidation by the marine strain MB2. In addition, we measured the fractionation of carbon isotopes during formation of methane thiol (MeSH) from MeCl by the purified cobalamin-dependent enzyme, halomethane:bisulphide/halide ion methyltransferase (11) from CC495, to determine whether this initial step in MeCl degradation could account for the observed fractionation by whole cells. Finally, we determined the fractionation associated with the degradation of MeBr during field studies with agricultural soil by monitoring MeBr concentration and δ 13 C of MeBr in the headspace of flux chambers under fumigation conditions.

Proceedings of the National Academy of Sciences of↗