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At least 1,405 records · Page 78Linked to original sources
USGS2015

Natural soil reservoirs for human pathogenic and fecal indicator bacteria

Soils receive inputs of human pathogenic and indicator bacteria through land application of animal manures or sewage sludge, and inputs by wildlife. Soil is an extremely heterogeneous substrate and contains meso- and macrofauna that may be reservoirs for bacteria of human health concern. The ability to detect and quantify bacteria of human health concern is important in risk assessments and in evaluating the efficacy of agricultural soil management practices that are protective of crop quality and protective of adjacent water resources. The present chapter describes the distribution of selected Gram-positive and Gram-negative bacteria in soils. Methods for detecting and quantifying soilborne bacteria including extraction, enrichment using immunomagnetic capture, culturing, molecular detection and deep sequencing of metagenomic DNA to detect pathogens are overviewed. Methods for strain phenotypic and genotypic characterization are presented, as well as how comparison with clinical isolates can inform the potential for human health risk.

Book chapter↗
USGS2006

Monitored natural attenuation of chlorinated solvents: Moving beyond reductive dechlorination

Monitored natural attenuation (MNA), while a remedy of choice for many sites, can be challenging when the contaminants are chlorinated solvents. Even with many high-quality technical guidance references available, there continue to be challenges implementing MNA at some chlorinated solvent sites. The U.S. Department of Energy, as one organization facing such challenges, is leading a project that will incorporate developing concepts and tools into the existing toolbox for selecting and implementing MNA as a remediation option at sites with chlorinated solvent contamination. The structure and goals of this project were introduced in an article in the Winter 2004 issue of Remediation (Sink et al., 2004). This article is a summary of the three technical areas being developed through the project: mass balance, enhanced attenuation, and characterization and monitoring supporting the first two areas.

Remediation Journal↗
USGS1988

Using laser micro mass spectrometry with the LAMMA-1000 instrument for monitoring relative elemental concentrations in vitrinite

The variation in relative elemental concentrations among a series of coal macerals belonging to the vitrinite maceral group was determined using laser micro mass spectrometry (LAMMS). Variations in Ba, Cr, Ga, Sr, Ti, and V concentrations among the coals were determined using the LAMM A-1000 instrument. LAMMS analysis is not limited to these elements; their selection illustrates the application of the technique. Ba, Cr, Ga, Sr, Ti, and V have minimal site-to-site variance in the vitrinite macerals of the studied coals as measured by LAMMS. The LAMMS data were compared with bulk elemental data obtained by instrumental neutron activation analysis (INAA) and D. C. arc optical emission spectroscopy (DCAS) in order to determine the reliability of the LAMMS data. The complex nature of the ionization phenomena in LAMMS and the lack of standards characterized on a microscale makes obtaining quantitative elemental data within the ionization microvolume difficult; however, we demonstrate that the relative variation of an element among vitrinites from different coal beds in the eastern United States can be observed using LAMMS in a "bulk" mode by accumulating signal intensities over several microareas of each vitrinite. Our studies indicate gross changes (greater than a factor of 2 to 5 depending on the element) can be monitored when the elemental concentration is significantly above the detection limit. "Bulk" mode analysis was conducted to evaluate the accuracy of future elemental LAMMS microanalyses. The primary advantage of LAMMS is the inherent spatial resolution, ~ 20 ??m for coal. Two different vitrite bands in the Lower Bakerstown coal bed (CLB-1) were analyzed. The analysis did not establish any certain concentration differences in Ba, Cr, Ga, Sr, Ti, and V between the two bands. ?? 1988 Springer-Verlag.

Mikrochimica Acta↗
USGS2009

Conservation of northern bobwhite on private lands in Georgia, USA under uncertainty about landscape-level habitat effects

Large-scale habitat enhancement programs for birds are becoming more widespread, however, most lack monitoring to resolve uncertainties and enhance program impact over time. Georgia?s Bobwhite Quail Initiative (BQI) is a competitive, proposal-based system that provides incentives to landowners to establish habitat for northern bobwhites (Colinus virginianus). Using data from monitoring conducted in the program?s first years (1999?2001), we developed alternative hierarchical models to predict bobwhite abundance in response to program habitat modifications on local and regional scales. Effects of habitat and habitat management on bobwhite population response varied among geographical scales, but high measurement variability rendered the specific nature of these scaled effects equivocal. Under some models, BQI had positive impact at both local farm scales (1, 9 km2), particularly when practice acres were clustered, whereas other credible models indicated that bird response did not depend on spatial arrangement of practices. Thus, uncertainty about landscape-level effects of management presents a challenge to program managers who must decide which proposals to accept. We demonstrate that optimal selection decisions can be made despite this uncertainty and that uncertainty can be reduced over time, with consequent improvement in management efficacy. However, such an adaptive approach to BQI program implementation would require the reestablishment of monitoring of bobwhite abundance, an effort for which funding was discontinued in 2002. For landscape-level conservation programs generally, our approach demonstrates the value in assessing multiple scales of impact of habitat modification programs, and it reveals the utility of addressing management uncertainty through multiple decision models and system monitoring.

Landscape Ecology↗
USGS1979

Robust estimation of population size when capture probabilities vary among animals

A model is given for multiple recapture studies on closed populations which allows capture probabilities to vary among individuals. The capture probability of each individual is assumed to be constant over time. Based on this model we give a nonparametric estimation procedure for population size. The estimator involves selecting one of a sequence of estimator which are each linear combinations of the capture frequencies. The individual estimators are derived from the generalized jackknife method. We also give a goodness of fit test for the model's assumption that individual capture probabilities do not change during the study. The robustness of the estimation procedure is investigated with a simulation study. By virtue of this study, and the theoretical nature of the estimator, it is judged to be robust to moderate variations in individual capture probabilities which may occur in commonly used short-term livetrapping studies.

Ecology↗
USGS2009

Decision Support System for Evaluation of Gunnison River Flow Regimes With Respect To Resources of the Black Canyon of the Gunnison National Park

This report describes and documents a decision support system for the Gunnison River in Black Canyon of the Gunnison National Park. It is a macro-embedded EXCEL program that calculates and displays indicators representing valued characteristics or processes in the Black Canyon based on daily flows of the Gunnison River. The program is designed to easily accept input from downloaded stream gage records or output from the RIVERWARE reservoir operations model being used for the upstream Aspinall Unit. The decision support system is structured to compare as many as eight alternative flow regimes, where each alternative is represented by a daily sequence of at least 20 calendar years of streamflow. Indicators include selected flow statistics, riparian plant community distribution, clearing of box elder by inundation and scour, several measures of sediment mobilization, trout fry habitat, and federal reserved water rights. Calculation of variables representing National Park Service federal reserved water rights requires additional secondary input files pertaining to forecast and actual basin inflows and storage levels in Blue Mesa reservoir. Example input files representing a range of situations including historical, reconstructed natural, and simulated alternative reservoir operations are provided with the software.

Open-File Report↗
USGS2023

Distribution of chlorinated volatile organic compounds and per- and polyfluoroalkyl substances in groundwater and surface water at the former Naval Air Warfare Center, West Trenton, New Jersey, 2018

Groundwater wells and surface-water storm sewers contaminated with volatile organic compounds (VOCs) and per- and polyfluoroalkyl substances (PFASs) at the former Naval Air Warfare Center (NAWC) site in West Trenton, New Jersey were sampled in 2018 as part of the Navy’s long-term monitoring program. Trichloroethene (TCE), cis-1,2-dichloroethene (cisDCE), and vinyl chloride concentrations were plotted in map view and selected cross sections to elucidate the vertical and horizontal extent and distribution of contamination, along with a tabular comparison between 2018 and previous analytical results. The 2018 data showed that the areas of VOC contamination (>1 microgram per liter) decreased slightly on the north and east sides of the NAWC site from previous sampling dates; these decreases are attributed to the influence of the pump-and-treat system, natural attenuation processes, and various engineered bioaugmentation experiments that have occurred onsite. Off-site groundwater samples indicate the VOC contaminated groundwater is likely hydraulically constrained by the pump-and-treat system and appears to not be moving offsite to the south and west of NAWC. Only one offsite well, 50BR, located along the eastern margin of the site, was found to have detectable TCE and cisDCE concentrations, indicating that VOC contamination continues to migrate a short distance offsite to the east. Detectable VOC contamination was found in wells as deep as 200 and 221 feet on both the east and west sides of the NAWC site. Comparisons of present-day data to data from past sampling efforts indicate that TCE concentrations in most wells have decreased slowly over time. Results from surface-water samples indicate that VOCs enter surface water predominantly through the West Ditch drainage system. Concentrations and fluxes of VOCs are higher when groundwater levels are higher, indicating contaminated groundwater discharges into the surface water system. Higher VOC concentrations at the Interceptor site relative to other sites in the West Ditch indicate the contamination in the West Ditch system is likely caused by contaminated groundwater discharging to the West Ditch storm sewer near manhole MH-140 when water table levels are high. The pump-and-treat extraction wells at the former NAWC site were sampled for per- and polyfluoroalkyl substances (PFAS) in 2018. The suite of reported PFAS include perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid, and perfluorobutane sulfonate. Concentrations were plotted in map view to determine the areal extent of the PFAS contamination at the site. Extraction well 48BR sampled on the eastern half of the site was found to have PFOS and PFOA concentrations greater than the New Jersey Department of Environmental Protection Drinking Water maximum contaminant levels (MCLs), which is consistent with the distribution of highest PFAS concentrations in surface water in the OF-4 storm sewer system that drains that area, as well as previously collected PFAS concentrations in monitoring wells. On the western half of the site, the extraction well 08BR sample exceeded MCLs for PFOA and PFOS and the extraction well 22BR sample exceeded the MCL for PFOA, but samples from all other extraction wells were below the MCLs or other criteria for all PFAS analyzed. Concentrations of PFOA exceeded concentrations of PFOS on the west side of NAWC in both groundwater and surface water, which contrasts with the conditions on the east side of NAWC where PFOS concentrations exceeded PFOA concentrations. However, this observation was based on a limited number of samples on the west side of NAWC from 2018 and previous years, so more PFAS sampling is needed on the west side to assess this further.

New Jersey↗
USGS1996

Use of a ground-water flow model with particle tracking to evaluate ground-water vulnerability, Clark County, Washington

A ground-water flow model was used in conjunction with particle tracking to evaluate ground-water vulnerability in Clark County, Washington. Using the particle-tracking program, particles were placed in every cell of the flow model (about 60,000 particles) and tracked backwards in time and space upgradient along flow paths to their recharge points. A new computer program was developed that interfaces the results from a particle-tracking program with a geographic information system (GIS). The GIS was used to display and analyze the particle-tracking results. Ground-water vulnerability was evaluated by selecting parts of the ground-water flow system and combining the results with ancillary information stored in the GIS to determine recharge areas, characteristics of recharge areas, downgradient impact of land use at recharge areas, and age of ground water. Maps of the recharge areas for each hydrogeologic unit illustrate the presence of local, intermediate, or regional ground-water flow systems and emphasize the three-dimensional nature of the ground-water flow system in Clark County. Maps of the recharge points for each hydrogeologic unit were overlaid with maps depicting aquifer sensitivity as determined by DRASTIC (a measure of the pollution potential of ground water, based on the intrinsic characteristics of the near-surface unsaturated and saturated zones) and recharge from on-site waste-disposal systems. A large number of recharge areas were identified, particularly in southern Clark County, that have a high aquifer sensitivity, coincide with areas of recharge from on-site waste-disposal systems, or both. Using the GIS, the characteristics of the recharge areas were related to the downgradient parts of the ground-water system that will eventually receive flow that has recharged through these areas. The aquifer sensitivity, as indicated by DRASTIC, of the recharge areas for downgradient parts of the flow system was mapped for each hydrogeologic unit. A number of public-supply wells in Clark County may be receiving a component of water that recharged in areas that are more conducive to contaminant entry. The aquifer sensitivity maps illustrate a critical deficiency in the DRASTIC methodology: the failure to account for the dynamics of the ground-water flow system. DRASTIC indices calculated for a particular location thus do not necessarily reflect the conditions of the ground-water resources at the recharge areas to that particular location. Each hydrogeologic unit was also mapped to highlight those areas that will eventually receive flow from recharge areas with on-site waste-disposal systems. Most public-supply wells in southern Clark County may eventually receive a component of water that was recharged from on-site waste-disposal systems.Traveltimes from particle tracking were used to estimate the minimum and maximum age of ground water within each model-grid cell. Chlorofluorocarbon (CFC)-age dating of ground water from 51 wells was used to calibrate effective porosity values used for the particle- tracking program by comparison of ground-water ages determined through the use of the CFC-age dating with those calculated by the particle- tracking program. There was a 76 percent agreement in predicting the presence of modern water in the 51 wells as determined using CFCs and calculated by the particle-tracking program. Maps showing the age of ground water were prepared for all the hydrogeologic units. Areas with the youngest ground-water ages are expected to be at greatest risk for contamination from anthropogenic sources. Comparison of these maps with maps of public- supply wells in Clark County indicates that most of these wells may withdraw ground water that is, in part, less than 100 years old, and in many instances less than 10 years old. Results of the analysis showed that a single particle-tracking analysis simulating advective transport can be used to evaluate ground-water vulnerability for any part of a ground-wate

Open-File Report↗
USGS2007

Prioritizing bottomland hardwood forest sites for protection and augmentation

Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these restoration efforts has focused on developing tools that can be used for both assessments at the landscape level and policy implementation at the local level. The distribution of bottomland hardwood forests in the Cache and White River watersheds in eastern Arkansas were examined using existing GIS databases. Criteria were developed to select areas that should be conserved or augmented for wildlife habitat. Over 67% of the study area was classified as agriculture, with bottomland hardwood forest the next largest habitat class. The thickness of a forest fragment was defined as the radius of the largest circle that can be inscribed in a fragment. Thickness was used in three ways. First, individual forest fragments were identified and selected based on ecological function using criteria we established. Second, individual fragments that were too small to support interior species, but large enough that if moderately augmented they could recover that function, were identified and selected. These augmentable fragments were further prioritized by adjacency to habitat that might be suitable for reforestation, namely agriculture. Third, watersheds were prioritized for conservation and augmentation based on the size and distributions of forest fragment thickness and area within each watershed.

Arkansas↗
USGS2015

A methodology for quantifying and mapping ecosystem services provided by watersheds

Watershed processes – physical, chemical, and biological – are the foundation for many benefits that ecosystems provide for human societies. A crucial step toward accurately representing those benefits, so they can ultimately inform decisions about land and water management, is the development of a coherent methodology that can translate available data into the ecosystem services (ES) produced by watersheds. Ecosystem services (ES) provide an instinctive way to understand the tradeoffs associated with natural resource management. We provide a synthesis of common terminology and explain a rationale and framework for distinguishing among the components of ecosystem service delivery, including: an ecosystem’s capacity to produce a service; societal demand for the service; ecological pressures on this service; and flow of the service to people. We discuss how interpretation and measurement of these components can differ among provisioning, regulating, and cultural services and describe selected methods for quantifying ES components as well as constraints on data availability. We also present several case studies to illustrate our methods, including mapping capacity of several water purification services and demand for two forms of wildlife-based recreation, and discuss future directions for ecosystem service assessments. Our flexible framework treats service capacity, demand, ecological pressure, and flow as separate but interactive entities to better evaluate the sustainability of service provision across space and time and to help guide management decisions.

Book chapter↗
USGS2013

Blood from a turnip: tissue origin of low-coverage shotgun sequencing libraries affects recovery of mitogenome sequences

Next generation sequencing methods allow rapid, economical accumulation of data that have many applications, even at relatively low levels of genome coverage. However, the utility of shotgun sequencing data sets for specific goals may vary depending on the biological nature of the samples sequenced. We show that the ability to assemble mitogenomes from three avian samples of two different tissue types varies widely. In particular, data with coverage typical of microsatellite development efforts (∼1×) from DNA extracted from avian blood failed to cover even 50% of the mitogenome, relative to at least 500-fold coverage from muscle-derived data. Researchers should consider possible applications of their data and select the tissue source for their work accordingly. Practitioners analyzing low-coverage shotgun sequencing data (including for microsatellite locus development) should consider the potential benefits of mitogenome assembly, including internal barcode verification of species identity, mitochondrial primer development, and phylogenetics.

Mitochondrial DNA↗
USGS2009

Estimated Perennial Streams of Idaho and Related Geospatial Datasets

The perennial or intermittent status of a stream has bearing on many regulatory requirements. Because of changing technologies over time, cartographic representation of perennial/intermittent status of streams on U.S. Geological Survey (USGS) topographic maps is not always accurate and (or) consistent from one map sheet to another. Idaho Administrative Code defines an intermittent stream as one having a 7-day, 2-year low flow (7Q2) less than 0.1 cubic feet per second. To establish consistency with the Idaho Administrative Code, the USGS developed regional regression equations for Idaho streams for several low-flow statistics, including 7Q2. Using these regression equations, the 7Q2 streamflow may be estimated for naturally flowing streams anywhere in Idaho to help determine perennial/intermittent status of streams. Using these equations in conjunction with a Geographic Information System (GIS) technique known as weighted flow accumulation allows for an automated and continuous estimation of 7Q2 streamflow at all points along a stream, which in turn can be used to determine if a stream is intermittent or perennial according to the Idaho Administrative Code operational definition. The selected regression equations were applied to create continuous grids of 7Q2 estimates for the eight low-flow regression regions of Idaho. By applying the 0.1 ft3/s criterion, the perennial streams have been estimated in each low-flow region. Uncertainty in the estimates is shown by identifying a 'transitional' zone, corresponding to flow estimates of 0.1 ft3/s plus and minus one standard error. Considerable additional uncertainty exists in the model of perennial streams presented in this report. The regression models provide overall estimates based on general trends within each regression region. These models do not include local factors such as a large spring or a losing reach that may greatly affect flows at any given point. Site-specific flow data, assuming a sufficient period of record, generally would be considered to represent flow conditions better at a given site than flow estimates based on regionalized regression models. The geospatial datasets of modeled perennial streams are considered a first-cut estimate, and should not be construed to override site-specific flow data.

Data Series↗
USGS2024

Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses

This report describes scientific gaps that limit our ability to predict water-quality effects on water availability for beneficial uses across the United States. Water-quality constituents considered in the report include salinity, geogenic constituents, contaminants of emerging concern, and nitrogen. For each constituent, there is a selection of scientific gaps, approaches, and outcomes to help guide portions of the U.S. Geological Survey Water Mission Area ( https://www.usgs.gov/mission-areas/water-resources ) research portfolio and other national research efforts. Although the report is not comprehensive, and new issues are likely to emerge, it does provide an assessment of many of the major challenges and opportunities concerning water-quality effects on water availability for beneficial uses. Due to the changing nature of water-quality concerns, and to deal with issues not described in this report, it will be important to maintain broad-based expertise and flexibility to address the full spectrum of long-term water-quality issues facing the Nation’s water resources.

Open-File Report↗
USGS1999

Natural attenuation of chloroacetinilide herbicides in aquatic systems

Chloroacetanilide herbicides (e.g. alachlor and metolachlor) and their breakdown products are frequently found in agriculturally impacted and other natural waters. Although these compounds are usually present at low concentrations in aquatic systems, defining their fate and attenuation rate is important because they can be toxic at comparatively low exposure levels. This paper summarizes results from a four-year research program assessing factors that affect herbicide attenuation rates and breakdown product formation patterns in aquatic systems. Over 70 different field microcosms (11.3 m 3 cylindrical fiberglass tanks) were selectively manipulated (in replicate) to create nine unique aquatic ecosystems for this study. Alachlor and/or metolachlor were added to these units and transformations were observed over time. Alachlor half-lives ranged from 6.0 days to more than 100 days depending upon the temperature, oxygen conditions, and the nutrient conditions in the microcosm waters. The highest rates of alachlor decay were observed in warm, nutrient-rich, anaerobic water columns, whereas the lowest alachlor decay rates were observed under cooler, aerobic, oligotrophic water conditions. Similar relationships were observed for metolachlor, although metolachlor decay rates were about 40% slower. Our data suggest that herbicides will decay rapidly in waters that are high in nutrients possibly resulting from human activities. Alternately, low nutrient or pristine waters will have the lowest rates of herbicide decay. On a policy level, all efforts should be made to prevent exposure of comparatively pristine waters to herbicide inputs.

Conference Paper↗
USGS2011

Pathogens and diseases of freshwater mussels in the United States: Studies on bacterial transmission and depuration

Unionid mussels are recognized as important contributors to healthy aquatic ecosystems, as well as bioindicators of environmental perturbations. Because they are sedentary, filter feeding animals and require hosts (i.e., fishes) to transform embryonic glochidia, mussels are susceptible to direct adverse environmental parameters, and indirect parameters that restrict the timely presence of the host(s). Their numbers have declined in recent decades to a point that this fauna is regarded as one of the most imperiled in North America. The most significant threat to populations of native unionids in recent years has been the introduction and spread of zebra mussels Dreissena polymorpha. Many federal and state agencies, and private interests are now engaged in mussel conservation efforts, including collecting selected imperiled species from impacted rivers and lakes and propagating them at refuges for future population augmentations. One essential consideration with mussel propagation and their intensive culture at refugia is the prevention of pathogen introductions and control of diseases. Currently, there are few reports of etiological agents causing diseases among freshwater mussels; however, because of increased observations of mussel die-offs in conjunction with transfers of live animals between natural waters and refugia, disease problems can be anticipated to emerge. This review summarizes research to develop bacterial isolation techniques, study pathogen transmission between fish and mussels, identify causes of seasonal mussel die-offs, and develop non-destructive methods for pathogen detection. These efforts were done to develop disease preventative techniques for use by resource managers to avoid potential large-scale disease problems in restoration and population augmentation efforts among imperiled populations.

Conference Paper↗
USGS2006

Usoi dam wave overtopping and flood routing in the Bartang and Panj Rivers, Tajikistan

The Usoi dam was created in the winter of 1911 after an enormous seismogenic rock slide completely blocked the valley of the Bartang River in the Pamir Mountains of southeastern Tajikistan. At present the dam impounds 17 million cubic meters of water in Lake Sarez. Flood volume and discharge estimates were made for several landslide generated floods that could overtop the dam. For landslide volumes of 200, 500, and 1,000 million cubic meters, estimated overtopping flood volumes were 2, 22, and 87 million cubic meters of water, respectively. Estimated peak discharge at the dam for these three flood scenarios were 57,000, 490,000, and 1,580,000 m3/s, based on triangular hydrographs of 70-, 90-, and 110-s durations, respectively. Flood-routing simulations were made for the three landslide-induced overtopping floods over a 530-km reach of the Bartang and Panj Rivers below the Usoi dam. A one-dimensional flow model using a Riemann numerical solution technique was selected for the analysis. For the 87 million cubic meter volume overtopping flood scenario, the peak flows were approximately 1, 100, 800, and 550 m3/s at locations 50, 100, and 150 km downstream of the dam respectively. ?? Springer 2006.

Natural Hazards↗
USGS2012

Atmospheric deposition, water-quality, and sediment data for selected lakes in Mount Rainer, North Cascades, and Olympic National Parks, Washington, 2008-10

To evaluate the potential effect from atmospheric deposition of nitrogen to high-elevation lakes, the U.S. Geological Survey partnered with the National Park Service to develop a "critical load" of nitrogen for sediment diatoms. A critical load is defined as the level of a given pollutant (in this case, nitrogen) at which detrimental effects to a target endpoint (sediment diatoms) result. Because sediment diatoms are considered one of the "first responders" to ecosystem changes from nitrogen, they are a sensitive indicator for nitrogen deposition changes in natural areas. This report presents atmospheric deposition, water quality, sediment geochronology, and sediment diatom data collected from July 2008 through August 2010 in support of this effort.

Washington↗
USGS1991

[Book review] Seabirds of Hawaii: Natural history and conservation

This volume is a rather odd contribution, a hybrid between an academic work and a popular book, and both suffers and benefits from these attributes. The 18 chapters are divided into four parts that deal with the environment and humans (3 chapters and ca. 12% of the text), comparative biology of Hawaiian seabirds (5 chapters, 26%), treatments of Hawaiian seabird groups by family (7 chapters, 34%), and conservation (3 chapters, 16%). At the end of the book are an appendix of common and scientific names for plants, birds, mammals, fish, and a few invertebrates; a 6-page "selected" bibliography with pertinent references for each chapter; and an index.

The Auk↗