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At least 235 records · Page 13Linked to original sources
USGS2017

Analysis of trends of water quality and streamflow in the Blackstone, Branch, Pawtuxet, and Pawcatuck Rivers, Massachusetts and Rhode Island, 1979 to 2015

Trends in long-term water-quality and streamflow data from six water-quality-monitoring stations within three major river basins in Massachusetts and Rhode Island that flow into Narragansett Bay and Little Narragansett Bay were evaluated for water years 1979–2015. In this study, conducted by the U.S. Geological Survey in cooperation with the Rhode Island Department of Environmental Management, the Rhode Island Water Resources Board, and the U.S. Environmental Protection Agency, water-quality and streamflow data were evaluated with a Weighted Regressions on Time, Discharge, and Season smoothing method, which removes the effects of year-to-year variation in water-quality conditions due to variations in streamflow (discharge). Trends in annual mean, annual median, annual maximum, and annual 7-day minimum flows at four continuous streamgages were evaluated by using a time-series smoothing method for water years 1979–2015. Water quality at all monitoring stations changed over the study period. Decreasing trends in flow-normalized nutrient concentrations and loads were observed during the period at most monitoring stations for total nitrogen, nitrite plus nitrate, and total phosphorus. Average flow-normalized loads for water years 1979–2015 decreased in the Blackstone River by up to 46 percent in total nitrogen, 17 percent in nitrite plus nitrate, and 69 percent in total phosphorus. The other rivers also had decreasing flow-normalized trends in nutrient concentrations and loads, except for the Pawtuxet River, which had an increasing trend in nitrite plus nitrate. Increasing trends in flow-normalized chloride concentrations and loads were observed during the study period at all of the rivers, with increases of more than 200 percent in the Blackstone River. Small increasing trends in annual mean daily streamflow were observed in 3 of the 4 rivers, with increases of 1.2 to 11 percent; however, the trends were not significant. All 4 rivers had decreases in streamflow for the annual 7-day minimums, but only 3 of the 4 rivers had decreases that were significant (34 to 54 percent). The Branch River had decreasing annual mean daily streamflow (7.5 percent) and the largest decrease in the annual 7-day minimum streamflow. The Blackstone and Pawtuxet Rivers had the largest increases in annual maximum daily flows but had decreases in the annual 7-day minimum flows.

Massachusetts, Rhode Island↗
USGS2024

Mass-balance-consistent geological stock accounting: A new approach toward sustainable management of mineral resources

Global resource extraction raises concerns about environmental pressures and the security of mineral supply. Strategies to address these concerns depend on robust information on natural resource endowments, and on suitable methods to monitor and model their changes over time. However, current mineral resources and reserves reporting and accounting workflows are poorly suited for addressing mineral depletion or answering questions about the long-term sustainable supply. Our integrative review finds that the lack of a robust theoretical concept and framework for mass-balance (MB)-consistent geological stock accounting hinders systematic industry-government data integration, resource governance, and strategy development. We evaluate the existing literature on geological stock accounting, identify shortcomings of current monitoring of mine production, and outline a conceptual framework for MB-consistent system integration based on material flow analysis (MFA). Our synthesis shows that recent developments in Earth observation, geoinformation management, and sustainability reporting act as catalysts that make MB-consistent geological stock accounting increasingly feasible. We propose first steps for its implementation and anticipate that our perspective as “resource realists” will facilitate the integration of geological and anthropogenic material systems, help secure future mineral supply, and support the global sustainability transition.

Environmental Science and Technology↗
USGS1996

Ground-water quality, water year 1995, and statistical analysis of ground-water-quality data, water years 1994-95, at the chromic acid pit site, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso, Texas

The Chromic Acid Pit site is an inactive waste disposal site that is regulated by the Resource Conservation and Recovery Act of 1976. The 2.2-cubic-yard cement-lined pit was operated from 1980 to 1983 by a contractor to the U.S. Army Air Defense Artillery Center and Fort Bliss. The pit, located on the Fort Bliss military reservation in El Paso, Texas, was used for disposal and evaporation of chromic acid waste generated from chrome plating operations. The site was closed in 1989, and the Texas Natural Resources Conservation Commission issued permit number HW-50296 (U.S. Environmental Protection Agency number TX4213720101), which approved and implemented post-closure care for the Chromic Acid Pit site. In accordance with an approved post-closure plan, the U.S. Geological Survey is cooperating with the U.S. Army in monitoring and evaluating ground-water quality at the site. One upgradient ground-water monitoring well (MW1) and two downgradient ground-water monitoring wells (MW2 and MW3), installed adjacent to the chromic acid pit, are monitored on a quarterly basis. Ground-water sampling of these wells by the U.S. Geological Survey began in December 1993. The ground-water level, measured in a production well located approximately 1,700 feet southeast of the Chromic Acid Pit site, has declined about 29.43 feet from 1982 to 1995. Depth to water at the Chromic Acid Pit site in September 1995 was 284.2 to 286.5 feet below land surface; ground-water flow at the water table is assumed to be toward the southeast. Ground-water samples collected from monitoring wells at the Chromic Acid Pit site during water year 1995 contained dissolved- solids concentrations of 481 to 516 milligrams per liter. Total chromium concentrations detected above the laboratory reporting limit ranged from 0.0061 to 0.030 milligram per liter; dissolved chromium concentrations ranged from 0.0040 to 0.010 milligram per liter. Nitrate as nitrogen concentrations ranged from 2.1 to 2.8 milligrams per liter; nitrite plus nitrate as nitrogen concentrations ranged from 2.4 to 3.2 milligrams per liter. Water samples from wells MW1 and MW2 were analyzed for volatile organic compounds for the first quarter; no confirmed volatile organic compounds were detected above laboratory reporting limits. Detected chemical concentrations in water from the chromic acid pit monitoring wells during the four sampling periods were below U.S. Environmental Protection Agency-established maximum contaminant levels for public drinking-water supplies. Overall, water-quality characteristics of water from the chromic acid pit ground-water monitoring wells are similar to those of other wells in the surrounding area. Statistical analyses were performed on 56 of the chemical constituents analyzed for in ground water from the chromic acid pit monitoring wells. Concentrations of chloride, fluoride, sulfate, and potassium were significantly less in water from one or both downgradient wells than in water from the upgradient well. Concentrations of nitrate as nitrogen, nitrite plus nitrate as nitrogen, and dissolved solids were significantly greater in water from the downgradient wells than in water from the upgradient well. Concentrations of nitrate as nitrogen, chloride, and potassium were significantly different in water from the two downgradient wells. Statistical analysis of chemical constituents in water from the chromic acid pit monitoring wells did not appear to indicate a release of hazardous chemicals from the chromic acid pit. There was no indication of ground-water contamination in either downgradient well.

Texas↗
USGS2021

System characterization report on the Gaofen-1

Executive Summary This report addresses system characterization of Gaofen-1 and is part of a series of system characterization reports produced and delivered by the U.S. Geological Survey Earth Resources Observation and Science Cal/Val Center of Excellence in 2020. These reports present the detail methodology and procedures for characterization; present technical and operational information about the specific sensing system being evaluated; and provide a summary of test measurements, data retention practices, data analysis results, and conclusions. Gaofen represents a series of Chinese high-resolution Earth observation satellites. More than 12 satellites have been launched in the Gaofen series, beginning with Gaofen-1 in 2013. Satellites within the series have varying infrared, radar, and optical imaging capabilities. The primary goal for the satellite is to provide near real-time observations for climate change monitoring, geographical mapping, precision agriculture support, environmental and resource surveying, and disaster prevention. More information on Chinese satellites and sensors is available within the “2020 Joint Agency Commercial Imagery Evaluation—Remote Sensing Satellite Compendium” and at http://www.cnsageo.com/#/detailIndex?secondIndex=2&id=3&code=8 . The Earth Resources Observation and Science Cal/Val Center of Excellence System Characterization team completed data analyses to characterize the geometric (interior and exterior), radiometric, and spatial performances. Results of these analyses indicate that Gaofen-1 has an interior geometric performance of −0.48 meter (m) (−0.03 pixel) northing and 0.42 m (0.03 pixel) easting offset for band 1, −0.99 m (−0.06 pixel) northing and −0.38 m (−0.02 pixel) easting offset for band 2, −0.45 m (−0.03) northing and 0.83 m (0.05 pixel) easting offset for band 3, −3.20 m (−0.20 pixel) northing and 1.44 m (0.09 pixel) easting offset for band 4 in band-to-band registration. Similarly, Gaofen-1 has an exterior geometric performance of 7.50 m (0.48 pixel) easting and 109.50 m (7.30 pixels) northing offset in comparison to the Landsat 8 Operational Land Imager; a radiometric performance in the range of −0.014 to 0.149 (absolute reflective difference); and a spatial performance in the range of 1.1 to 2.0 pixels at full width at half maximum, with a modulation transfer function at a Nyquist frequency in the range of 0.040 to 0.250.

Open-File Report↗
USGS2000

Regression analysis and real-time water-quality monitoring to estimate constituent concentrations, loads, and yields in the Little Arkansas River, south-central Kansas, 1995-99

Water from the Little Arkansas River is used as source water for artificial recharge to the Equus Beds aquifer, which provides water for the city of Wichita in south-central Kansas. To assess the quality of the source water, continuous in-stream water-quality monitors were installed at two U.S. Geological Survey stream-gaging stations to provide real-time measurement of specific conductance, pH, water temperature, dissolved oxygen, and turbidity in the Little Arkansas River. In addition, periodic water samples were collected manually and analyzed for selected constituents, including alkalinity, dissolved solids, total suspended solids, chloride, sulfate, atrazine, and fecal coliform bacteria. However, these periodic samples do not provide real-time data on which to base aquifer-recharge operational decisions to prevent degradation of the Equus Beds aquifer. Continuous and periodic monitoring enabled identification of seasonal trends in selected physical properties and chemical constituents and estimation of chemical mass transported in the Little Arkansas River. Identification of seasonal trends was especially important because high streamflows have a substantial effect on chemical loads and because concentration data from manually collected samples often were not available. Therefore, real-time water-quality monitoring of surrogates for the estimation of selected chemical constituents in streamflow can increase the accuracy of load and yield estimates and can decrease some manual data-collection activities. Regression equations, which were based on physical properties and analysis of water samples collected from 1995 through 1998 throughout 95 percent of the stream's flow duration, were developed to estimate alkalinity, dissolved solids, total suspended solids, chloride, sulfate, atrazine, and fecal coliform bacteria concentrations. Error was evaluated for the first year of data collection and each subsequent year, and a decrease in error was observed as the number of samples increased. Generally, 2 years of data (35 to 55 samples) collected throughout 90 to 95 percent of the stream's flow duration were sufficient to define the relation between a constituent and its surrogate(s). Relations and resulting equations were site specific. To test the regression equations developed from the first 3 years of data collection (1995-98), the equations were applied to the fourth year of data collection (1999) to calculate estimated constituent loads and the errors associated with these loads. Median relative percentage differences between measured constituent loads determined using the analysis of periodic, manual water samples and estimated constituent loads were less than 25 percent for alkalinity, dissolved solids, chloride, and sulfate. The percentage differences for total suspended solids, atrazine, and bacteria loads were more than 25 percent. Even for those constituents with large relative percentage differences between the measured and estimated loads, the estimation of constituent concentrations with regression analysis and real-time water-quality monitoring has numerous advantages over periodic manual sampling. The timely availability of bacteria and other constituent data may be important when considering recreation and the whole-body contact criteria established by the Kansas Department of Health and Environment for a specific water body. In addition, water suppliers would have timely information to use in adjusting water-treatment strategies; environmental changes could be assessed in time to prevent negative effects on fish or other aquatic life; and officials for the Equus Beds Ground-Water Recharge Demonstration project could use this information to prevent the possible degradation of the Equus Beds aquifer by choosing not to recharge when constituent concentrations in the source water are large. Constituent loads calculated from the regression equations may be useful for calculating total maximum daily loads (TMDL's), wh

Water-Resources Investigations Report↗
USGS2012

Water-quality characteristics of Michigan's inland lakes, 2001-10

The U.S. Geological Survey and the Michigan Department of Environmental Quality (MDEQ) jointly monitored for selected water-quality constituents and properties of inland lakes during 2001–10 as part of Michigan's Lake Water-Quality Assessment program. During 2001–10, 866 lake basins from 729 inland lakes greater than 25 acres were monitored for baseline water-quality conditions and trophic status. This report summarizes the water-quality characteristics and trophic conditions of the monitored lakes throughout the State; the data include vertical-profile measurements, nutrient measurements at three discrete depths, Secchi-disk transparency (SDT) measurements, and chlorophyll a measurements for the spring and summer, with major ions and other chemical indicators measured during the spring at mid-depth and color during the summer from near-surface samples. In about 75 percent of inland lake deep basins (index stations), trophic characteristics were associated with oligotrophic or mesotrophic conditions; 5 percent or less were categorized as hypereutrophic, and 80 percent of hypereutrophic lakes had a maximum depth of 30 feet or less. Comparison of spring and summer measurements shows that water clarity based on SDT measurements were clearer in the spring than in the summer for 63 percent of lakes. For near-surface measurements made in spring, 97 percent of lakes can be considered phosphorus limited and less than half a percent nitrogen limited; for summer measurements, 96 percent of lakes can be considered phosphorus limited and less than half a percent nitrogen limited. Spatial patterns of major ions, alkalinity, and hardness measured in the spring at mid-depth all showed lower values in the Upper Peninsula of Michigan and a southward increase toward the southern areas of the Lower Peninsula, though the location of increase varied by constituent. A spatial analysis of the data based on U.S. Environmental Protection Agency Level III Ecoregions separated potassium, sulfate, and chloride concentrations fairly well, with a pattern of lower values in northern ecoregions trending toward higher values in southern ecoregions; lower and higher concentrations of magnesium, hardness, calcium, and alkalinity were well separated, but middle-range concentrations in central Michigan ecoregions were mixed. The highest concentrations of chloride and sodium were in the southeastern area of the Lower Peninsula. Lakes with multiple basins showed few statistically significant differences in constituent concentrations at the 95-percent confidence level among combinations of depths between basins. The most statistically significant differences were found for water temperature, with significant differences in somewhat less than half the combinations in the spring and just a few combinations in the summer. The lack of significant differences between major basins of multibasin lakes indicates that monitoring of trophic characteristics in all major basins might not be necessary for the majority of constituents in future sampling programs. Trophic characteristics based on the 2001–10 dataset were compared to trophic characteristics resulting from other Michigan sampling programs, including the volunteer Cooperative Lakes Monitoring Program coordinated by the MDEQ (measurements on 250 lakes in 2011), trophic-state predictions produced by relating existing measurements to remotely sensed data (measurements for about 3,000 lakes), and the National Lakes Assessment (NLA) statistically valid, probability-designed lakes program (measurements for 50 lakes in Michigan and about 1,100 lakes nationally). A higher percentage of oligotrophic lakes resulted when using SDT from the volunteer data and the 2001–10 dataset than when using the predicted measurements from remotely sensed data or the NLA. Comparing trophic characteristics from differently designed programs provides multiple interpretations of lake water-quality status in Michigan lakes. No directional statistically significant difference was found at the 95-percent confidence level among historical nutrients and trophic characteristics when comparing 445 lakes with historical data for 1974–84 with the 2001–10 dataset, though SDT did show statistically significant differences at the 95-percent confidence level. Depending on the primary indicator, 50–66 percent of lakes did not change trophic-status class, 13–23 percent moved towards the oligotrophic end of the TSI scale, and 20–25 percent moved a class towards the eutrophic end of the TSI scale. Increasing percentages of urban-dominant land cover in the drainage areas of lakes had a more positive correlation with chloride concentration than did increased percentages of other land-cover classes; there was also a slight correlation of urban-dominant land cover and calcium concentration. Removing data for lakes in southeastern Lower Michigan, known from previous reports to be higher in chloride, still resulted in a positive relation even though the coefficient of determination (R 2 value) decreased from 0.55 to 0.39. Dominant land-cover drainage areas were not strongly related to nutrients with respect to a linear relation, nor were lake drainage-area sizes.

Michigan↗
USGS2014

Landbird trends in national parks of the North Coast and Cascades Network, 2005-12

National parks in the North Coast and Cascades Network (NCCN) can fulfill vital roles as refuges for bird species dependent on late-successional forest conditions and as reference sites for assessing the effects of land-use and land-cover changes on bird populations throughout the larger Pacific Northwest region. Additionally, long-term monitoring of landbirds throughout the NCCN provides information that can inform decisions about important management issues in the parks, including visitor impacts, fire management, and the effects of introduced species. In 2005, the NCCN began implementing a network-wide Landbird Monitoring Project as part of the NPS Inventory and Monitoring Program. In this report, we discuss 8-year trends (2005–12) of bird populations in the NCCN, based on a sampling framework of point counts established in three large wilderness parks (Mount Rainier, North Cascades, and Olympic National Parks), 7-year trends at Lewis and Clark National Historical Park (sampled in 2006, 2008, 2010, and 2012), and 5-year trends at San Juan Islands National Historical Park (sampled in 2007, 2009, and 2011). Our analysis encompasses a fairly short time span for this long-term monitoring program. The first 2 years of the time series (2005 and 2006) were implemented as part of a limited pilot study that included only a small subset of the transects. The subsequent 6 years (2007–12) represent just a single cycle through 5 years of alternating panels of transects in the large parks, with the first of five alternating panels revisited for the first time in 2012. Of 204 transects that comprise the six sampling panels in the large parks, only 68 (one-third) have thus been eligible for revisit surveys (34 during every year after 2005, and an additional 34 only in 2012) and can contribute to our current trend estimates. We therefore initiated the current analysis with a primary goal of testing our analytical procedures rather than detecting trends that might be strong enough to drive conservation or management decisions in the parks or elsewhere. We expect that aggregated trend detection results may change substantially over the next several years, as the number of transects with revisit histories triples and the spatial dispersion of transects contributing to trend estimates also improves greatly. In the meantime, caution should be exercised in interpreting the importance of trends, as individual years can have very large influences on the direction and magnitude of trends in a time series of such limited duration (and limited numbers of repeat visits at the small parks). Nevertheless, we estimated trends for 43 species at Mount Rainier National Park, 53 species at North Cascades National Park Complex, and 41 species at Olympic National Park. Of 137 park-species combinations (including combined-park analyses), we found 16 significant decreases (12 percent) and five significant increases (4 percent). We identify several limitations of the current analytical framework for trend assessment but suggest that the overall sampling design is strong and amenable to analysis by more recently developed model-based methods. These could provide a more flexible framework for examining trends and other population parameters of interest, as well as testing hypotheses that relate the distribution and abundance of species to environmental covariates. A model-based approach would allow for modeling various components of the detection process and analyzing observations (detection process), population state (occupancy, population size, density), and change (trend, local extinction and colonization rates turnover) simultaneously. Finally, we also evaluate operational aspects of NCCN Landbird Monitoring Project, and conclude that our robust, multi-party partnership is successfully implementing the project as it was envisioned.

British Columbia;Oregon;Washington↗
USGS2010

Mercury in Indiana watersheds: Retrospective for 2001–2006

Information about total mercury and methylmercury concentrations in water samples and mercury concentrations in fish-tissue samples was summarized for 26 watersheds in Indiana that drain most of the land area of the State. Mercury levels were interpreted with information on streamflow, atmospheric mercury deposition, mercury emissions to the atmosphere, mercury in wastewater, and landscape characteristics. Unfiltered total mercury concentrations in 411 water samples from streams in the 26 watersheds had a median of 2.32 nanograms per liter (ng/L) and a maximum of 28.2 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 5.4 percent exceeded the 12-ng/L chronic-aquatic criterion, 59 percent exceeded the 1.8-ng/L Great Lakes human-health criterion, and 72.5 percent exceeded the 1.3-ng/L Great Lakes wildlife criterion. Mercury concentrations in water were related to streamflow, and the highest mercury concentrations were associated with the highest streamflows. On average, 67 percent of total mercury in streams was in a particulate form, and particulate mercury concentrations were significantly lower downstream from dams than at monitoring stations not affected by dams. Methylmercury is the organic fraction of total mercury and is the form of mercury that accumulates and magnifies in food chains. It is made from inorganic mercury by natural processes under specific conditions. Unfiltered methylmercury concentrations in 411 water samples had a median of 0.10 ng/L and a maximum of 0.66 ng/L. Methylmercury was a median 3.7 percent and maximum 64.8 percent of the total mercury in 252 samples for which methylmercury was reported. The percentages of methylmercury in water samples were significantly higher downstream from dams than at other monitoring stations. Nearly all of the total mercury detected in fish tissue was assumed to be methylmercury. Fish-tissue samples from the 26 watersheds had wet-weight mercury concentrations that exceeded the 0.3 milligram per kilogram (mg/kg) U.S. Environmental Protection Agency (USEPA) methylmercury criterion in 12.4 percent of the 1,731 samples. The median wet-weight concentration in the fish-tissue samples was 0.13 mg/kg, and the maximum was 1.07 mg/kg. A coarse-scale analysis of all fish-tissue data in each watershed and a fine-scale analysis of data within 5 kilometers (km) of the downstream end of each watershed showed similar results overall. Mercury concentrations in fish-tissue samples were highest in the White River watershed in southern Indiana and the Fall Creek watershed in central Indiana. In fish-tissue samples within 5 km of the downstream end of a watershed, the USEPA methylmercury criterion was exceeded by 45 percent of mercury concentrations from the White River watershed and 40 percent of the mercury concentration from the Fall Creek watershed. A clear relation between mercury concentrations in fish-tissue samples and methylmercury concentrations in water was not observed in the data from watersheds in Indiana. Average annual atmospheric mercury wet-deposition rates were mapped with data at 156 locations in Indiana and four surrounding states for 2001–2006. These maps revealed an area in southeastern Indiana with high mercury wet-deposition rates—from 15 to 19 micrograms per square meter per year (µg/m 2 /yr). Annual atmospheric mercury dry-deposition rates were estimated with an inferential method by using concentrations of mercury species in air samples at three locations in Indiana. Mercury dry deposition-rates were 5.6 to 13.6 µg/m 2 /yr and were 0.49 to 1.4 times mercury wet-deposition rates. Total mercury concentrations were detected in 96 percent of 402 samples of wastewater effluent from 50 publicly owned treatment works in the watersheds; the median concentration was 3.0 ng/L, and the maximum was 88 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 12 percent exceeded the 12-ng/L chronic-aquatic criterion, 68 percent exceeded the 1.8-ng/L Great Lakes human-health criterion, and 81 percent exceeded the 1.3-ng/L Great Lakes wildlife criterion. Annual stream mercury yields were calculated with a model by using the mercury concentrations in water samples and daily average streamflows for 2002–2006, normalized to the watershed drainage areas. The average annual total mercury stream yields ranged from 0.73 to 45.2 µg/m 2 /yr and were highest in two White River watersheds in central Indiana. Median methylmercury stream yield was 1.9 percent of the median total mercury stream yield. In most watersheds, average annual stream yields of total mercury were a fraction of the combined average annual atmospheric mercury wet-deposition and estimated annual dry-deposition loading rates, indicating that much of the stream mercury was attributable to atmospheric deposition. In two watersheds, average annual stream yields of total mercury were approximately twice the atmospheric mercury loading, indicating that some of the stream mercury apparently was not attributable to atmospheric deposition. Rather, some of the stream mercury yield potentially was contributed by mercury in wastewater discharges. Land-cover type corresponded with the mercury levels in three watersheds: (1) A watershed of the White River in central Indiana with a high percentage of urban land cover had some of the highest total mercury concentrations and stream mercury yields. The urban land cover and numerous permitted wastewater outfalls with mercury in treated effluent potentially contributed mercury to this watershed. (2) A monitoring station on the Maumee River in northeastern Indiana, downstream from a large area of urban land cover, recorded the highest stream mercury concentrations. The urban land cover and mercury detected in treated effluent potentially contributed to the high mercury concentrations at this station. (3) A watershed of the Patoka River in southern Indiana with a high percentage of forest land cover had the highest atmospheric mercury dry-deposition rate. The high dry-deposition rate from the forest land cover potentially contributed to the high mercury concentrations in this watershed. From a retrospective view, mercury concentrations in Indiana watersheds routinely exceeded criteria protective of humans and commonly exceeded criteria protective of wildlife. Atmospheric mercury wet deposition was a predominant factor, but not the single factor, affecting mercury in Indiana watersheds. Mercury in wastewater discharges and atmospheric mercury dry deposition apparently contributed a substantial part of the mercury yield from some watersheds. Dams and impoundments increased the percentage of methylmercury in downstream waters. Long-term monitoring of mercury in wet and dry atmospheric deposition, and in streams and reservoirs, coordinated with monitoring of mercury in fish, will be needed to detect whether mercury levels in Indiana watersheds change in the future.

Indiana↗
USGS2004

In situ expression of nifD in Geobacteraceae in subsurface sediments

In order to determine whether the metabolic state of Geobacteraceae involved in bioremediation of subsurface sediments might be inferred from levels of mRNA for key genes, in situ expression of nifD , a highly conserved gene involved in nitrogen fixation, was investigated. When Geobacter sulfurreducens was grown without a source of fixed nitrogen in chemostats with acetate provided as the limiting electron donor and Fe(III) as the electron acceptor, levels of nifD transcripts were 4 to 5 orders of magnitude higher than in chemostat cultures provided with ammonium. In contrast, the number of transcripts of recA and the 16S rRNA gene were slightly lower in the absence of ammonium. The addition of acetate to organic- and nitrogen-poor subsurface sediments stimulated the growth of Geobacteraceae and Fe(III) reduction, as well as the expression of nifD in Geobacteraceae . Levels of nifD transcripts in Geobacteraceae decreased more than 100-fold within 2 days after the addition of 100 μM ammonium, while levels of recA and total bacterial 16S rRNA in Geobacteraceae remained relatively constant. Ammonium amendments had no effect on rates of Fe(III) reduction in acetate-amended sediments or toluene degradation in petroleum-contaminated sediments, suggesting that other factors, such as the rate that Geobacteraceae could access Fe(III) oxides, limited Fe(III) reduction. These results demonstrate that it is possible to monitor one aspect of the in situ metabolic state of Geobacteraceae species in subsurface sediments via analysis of mRNA levels, which is the first step toward a more global analysis of in situ gene expression related to nutrient status and stress response during bioremediation by Geobacteraceae .

Applied and Environmental Microbiology↗
USGS2016

Ecoregions of California

Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. By recognizing the spatial differences in the capacities and potentials of ecosystems, ecoregions stratify the environment by its probable response to disturbance (Bryce and others, 1999). These general purpose regions are critical for structuring and implementing ecosystem management strategies across Federal agencies, State agencies, and nongovernment organizations that are responsible for different types of resources in the same geographical areas (Omernik and others, 2000). The approach used to compile this map is based on the premise that ecological regions are hierarchical and can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity (Wiken, 1986; Omernik, 1987, 1995). These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical level. A Roman numeral hierarchical scheme has been adopted for different levels of ecological regions. Level I is the coarsest level, dividing North America into 15 ecological regions. Level II divides the continent into 50 regions (Commission for Environmental Cooperation Working Group, 1997, map revised 2006). At level III, the continental United States contains 105 ecoregions and the conterminous United States has 85 ecoregions (U.S. Environmental Protection Agency, 2013). Level IV, depicted here for California, is a further refinement of level III ecoregions. Explanations of the methods used to define these ecoregions are given in Omernik (1995), Omernik and others (2000), and Omernik and Griffith (2014). California has great ecological and biological diversity. The State contains offshore islands and coastal lowlands, large alluvial valleys, forested mountain ranges, deserts, and various aquatic habitats. There are 13 level III ecoregions and 177 level IV ecoregions in California and most continue into ecologically similar parts of adjacent States of the United States or Mexico (Bryce and others, 2003; Thorson and others, 2003; Griffith and others, 2014). The California ecoregion map was compiled at a scale of 1:250,000. It revises and subdivides an earlier national ecoregion map that was originally compiled at a smaller scale (Omernik, 1987; U.S. Environmental Protection Agency, 2013). This poster is the result of a collaborative project primarily between U.S. Environmental Protection Agency (USEPA) Region IX, USEPA National Health and Environmental Effects Research Laboratory (Corvallis, Oregon), California Department of Fish and Wildlife (DFW), U.S. Department of Agriculture (USDA)–Natural Resources Conservation Service (NRCS), U.S. Department of the Interior–Geological Survey (USGS), and other State of California agencies and universities. The project is associated with interagency efforts to develop a common framework of ecological regions (McMahon and others, 2001). Reaching that objective requires recognition of the differences in the conceptual approaches and mapping methodologies applied to develop the most common ecoregion-type frameworks, including those developed by the USDA–Forest Service (Bailey and others, 1994; Miles and Goudy, 1997; Cleland and others, 2007), the USEPA (Omernik 1987, 1995), and the NRCS (U.S. Department of Agriculture–Soil Conservation Service, 1981; U.S. Department of Agriculture–Natural Resources Conservation Service, 2006). As each of these frameworks is further refined, their differences are becoming less discernible. Regional collaborative projects such as this one in California, where some agreement has been reached among multiple resource-management agencies, are a step toward attaining consensus and consistency in ecoregion frameworks for the entire nation.

California↗
USGS2011

Are two systemic fish assemblage sampling programmes on the upper Mississippi River telling us the same thing?

We applied an Index of Biotic Integrity (IBI) used on Wisconsin/Minnesota waters of the upper Mississippi River (UMR) to compare data from two systemic sampling programmes. Ability to use data from multiple sampling programmes could extend spatial and temporal coverage of river assessment and monitoring efforts. We normalized for effort and tested fish community data collected by the Environmental Monitoring and Assessment Program-Great Rivers Ecosystems (EMAP-GRE) 2004–2006 and the Long Term Resource Monitoring Program (LTRMP) 1993–2006. Each programme used daytime electrofishing along main channel borders but with some methodological and design differences. EMAP-GRE, designed for baseline and, eventually, compliance monitoring, used a probabilistic, continuous design. LTRMP, designed primarily for baseline and trend monitoring, used a stratified random design in five discrete study reaches. Analysis of similarity indicated no significant difference between EMAP-GRE and LTRMP IBI scores ( n =238; Global R = 0.052; significance level=0.972). Both datasets distinguished clear differences only between 'Fair' and 'Poor' condition categories, potentially supporting a 'pass–fail' assessment strategy. Thirteen years of LTRMP data demonstrated stable IBI scores through time in four of five reaches sampled. LTRMP and EMAPGRE IBI scores correlated along the UMR's upstream to downstream gradient (df [3, 25]; F =1.61; p =0.22). A decline in IBI scores from upstream to downstream was consistent with UMR fish community studies and a previous, empirically modelled human disturbance gradient. Comparability between EMAP-GRE (best upstream to downstream coverage) and LTRMP data (best coverage over time and across the floodplain) supports a next step of developing and testing a systemic, multi-metric fish index on the UMR that both approaches could inform.

Illinois;Iowa;Minnesota;Missouri;Wisconsin↗
USGS2018

Effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate, and diatom communities

Detecting trends in biological attributes is central to many stream monitoring programs; however, understanding how natural variability in environmental factors affects trend results is not well understood. We evaluated the influence of antecedent streamflow and sample timing (covariates) on trend estimates for fish, invertebrate, and diatom taxa richness and biological condition from 2002 to 2012 at 51 sites distributed across the conterminous United States. A combination of linear regression and Kendall‐tau test for trends were used to evaluate covariate influence on trend estimates. Adjusting for covariates changed the magnitude of trend estimates in two‐thirds of cases on average by 21%, most often reducing the estimated magnitude of the trend. Additionally, covariates influenced the interpretation of over one‐third of trend estimates by either strengthening or weakening trends after adjustment. Our findings clearly indicate that antecedent streamflow and sample timing influences trend estimates and subsequent interpretation. Accounting for covariates during trend analysis will enhance stream monitoring programs by providing a better understanding and interpretation of estimated changes in biological endpoints at monitored sites. Failure to account for antecedent streamflow and sample timing may lead to mischaracterization of a trend and/or misunderstanding of potential causes.

Journal of the American Water Resources Associatio↗
USGS2023

The Landscape Data Commons: A system for standardizing, accessing, and applying large environmental datasets for agroecosystem research and management

Understanding where, when, and why agroecosystems are changing requires quality information about ecosystems that span land tenure, ecological processes, and spatial scales. Over the past two decades, land management agencies and research groups have adopted a suite of standardized methods for monitoring rangelands, which have been implemented at over 85,000 monitoring locations globally. However, the ability to use these data to understand agroecosystem dynamics and change across scales and across land ownership has been limited because, until now, these data have not been available in a harmonized, accessible format for analyses, modeling, and decision-support tools. We present the Landscape Data Commons, a cyberinfrastructure platform that harmonizes and aggregates standardized agroecosystem data, enables linkages to models, and facilitates analysis and interpretation of data within decision-support tools. The Landscape Data Commons provides a community platform for users to contribute data and develop next-generation tools to support agroecosystem management through the 21st century.

Agricultural & Environmental Letters↗
USGS2005

Effects of landscape change on fish assemblage structure in a rapidly growing metropolitan area in North Carolina, USA

We evaluated a comprehensive set of natural and land-use attributes that represent the major facets of urban development at fish monitoring sites in the rapidly growing Raleigh-Durham, North Carolina metropolitan area. We used principal component and correlation analysis to obtain a nonredundant subset of variables that extracted most variation in the complete set. With this subset of variables, we assessed the effect of urban growth on fish assemblage structure. We evaluated variation in fish assemblage structure with nonmetric multidimensional scaling (NMDS). We used correlation analysis to identify the most important environmental and landscape variables associated with significant NMDS axes. The second NMDS axis is related to many indices of land-use/land-cover change and habitat. Significant correlations with proportion of largest forest patch to total patch size (r = -0.460, P < 0.01), diversity of patch types (r = 0.554, P < 0.001), and population density (r = 0.385, P < 0.05) helped identify NMDS axis 2 as a disturbance gradient. Positive and negative correlations between the abundance of redbreast sunfish Lepomis auritus and bluehead chub Nocomis leptocephalus, respectively, and NMDS axis 2 also were evident. The North Carolina index of biotic integrity and many of its component metrics were highly correlated with urbanization. These results indicate that aquatic ecosystem integrity would be optimized by a comprehensive integrated management strategy that includes the preservation of landscape function by maximizing the conservation of contiguous tracts of forested lands and vegetative cover in watersheds. ?? 2005 by the American Fisheries Society.

American Fisheries Society Symposium↗
USGS2019

Evaluation of multiple laboratory performance and variability in analysis of recreational freshwaters by a rapid Escherichia coli qPCR method (Draft Method C)

There is interest in the application of rapid quantitative polymerase chain reaction (qPCR) methods for recreational freshwater quality monitoring of the fecal indicator bacteria Escherichia coli ( E. coli ). In this study we determined the performance of 21 laboratories in meeting proposed, standardized data quality acceptance (QA) criteria and the variability of target gene copy estimates from these laboratories in analyses of 18 shared surface water samples by a draft qPCR method developed by the U.S. Environmental Protection Agency (EPA) for E. coli . The participating laboratories ranged from academic and government laboratories with more extensive qPCR experience to “new” water quality and public health laboratories with relatively little previous experience in most cases. Failures to meet QA criteria for the method were observed in 24% of the total 376 test sample analyses. Of these failures, 39% came from two of the “new” laboratories. Likely factors contributing to QA failures included deviations in recommended procedures for the storage and preparation of reference and control materials. A master standard curve calibration model was also found to give lower overall variability in log 10 target gene copy estimates than the delta-delta Ct (ΔΔCt) calibration model used in previous EPA qPCR methods. However, differences between the mean estimates from the two models were not significant and variability between laboratories was the greatest contributor to overall method variability in either case. Study findings demonstrate the technical feasibility of multiple laboratories implementing this or other qPCR water quality monitoring methods with similar data quality acceptance criteria but suggest that additional practice and/or assistance may be valuable, even for some more generally experienced qPCR laboratories. Special attention should be placed on providing and following explicit guidance on the preparation, storage and handling of reference and control materials.

Water Research↗
USGS2010

Evidence for a novel marine harmful algal bloom: Cyanotoxin (Microcystin) transfer from land to sea otters

"Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine "harmful algal bloom" in the Pacific coastal environment; that of hepatotoxic shellfish poisoning (HSP), suggesting that animals and humans are at risk from microcystin poisoning when consuming shellfish harvested at the land-sea interface.

California↗
USGS2003

The U.S. Geological Survey streamflow and observation-well network in Massachusetts and Rhode Island

The U.S. Geological Survey began systematic streamflow monitoring in Massachusetts nearly 100 years ago (1904) on the Connecticut River at Montague City. Since that time, hydrologic data collection has evolved into a monitoring network of 103 streamgage stations and 200 ground-water observation wells in Massachusetts and Rhode Island (2000 water year). Data from this network provide critical information for a variety of purposes to Federal, State, and local government agencies, engineering consultants, and the public. The uses of this information have been enhanced by the fact that about 70 percent of the streamgage stations and a small but increasing number of observation wells in Massachusetts and Rhode Island have been equipped with digital collection platforms that transmit data by satellite every 4 hours. Twenty-one of the telemetered streamgage stations are also equipped with precipitation recorders. The near real-time data provided by these stations, along with historical data collected at all stations, are available over the Internet at no charge. The monitoring network operated during the 2000 water year was summarized and evaluated with respect to spatial distribution, the current uses of the data, and the physical characteristics associated with the monitoring sites. This report provides maps that show locations and summary tables for active continuous record streamgage stations, discontinued streamgage stations, and observation wells in each of the 28 major basins identified by the Massachusetts Executive Office of Environmental Affairs and five of the major Rhode Island basins. Metrics of record length, regulation, physiographic region and physical and land-cover characteristics indicate that the streamflow-monitoring network represents a wide range of drainage-area sizes, physiographic regions, and basin characteristics. Most streamgage stations are affected by regulation, which provides information for specific water-management purposes, but diminishes the usefulness of these stations for many types of hydrologic analysis. Only 26 of the 103 active streamgage stations operated by the U.S. Geological Survey in Massachusetts and Rhode Island are unaffected by regulation; of these, 17 are in Massachusetts and 9 are in Rhode Island. The paucity of unregulated stations is particularly evident when the stations are grouped into five drainage-area size classes; the fact that about half of these size classes have no representative unregulated stations underscores the importance of establishing and maintaining stations that are unaffected by regulation. The observation-well network comprises 200 wells; 80 percent of these wells are finished in sand and gravel, 19 percent are finished in till, and 1 percent are finished in bedrock. About 6 percent of the wells are equipped with continuous data recorders, and about half of these are capable of transmitting data in near real time.

Open-File Report↗
USGS2008

Introduction to Field Water-Quality Methods for the Collection of Metals - 2007 Project Summary

The U.S. Geological Survey (USGS), Region VI of the U.S. Environmental Protection Agency (USEPA), and the Osage Nation presented three 3-day workshops, in June-August 2007, entitled ?Introduction to Field Water-Quality Methods for the Collection of Metals.? The purpose of the workshops was to provide instruction to tribes within USEPA Region VI on various USGS surface-water measurement methods and water-quality sampling protocols for the collection of surface-water samples for metals analysis. Workshop attendees included members from over 22 tribes and pueblos. USGS instructors came from Oklahoma, New Mexico, and Georgia. Workshops were held in eastern and south-central Oklahoma and New Mexico and covered many topics including presampling preparation, water-quality monitors, and sampling for metals in surface water. Attendees spent one full classroom day learning the field methods used by the USGS Water Resources Discipline and learning about the complexity of obtaining valid water-quality and quality-assurance data. Lectures included (1) a description of metal contamination sources in surface water; (2) introduction on how to select field sites, equipment, and laboratories for sample analysis; (3) collection of sediment in surface water; and (4) utilization of proper protocol and methodology for sampling metals in surface water. Attendees also were provided USGS sampling equipment for use during the field portion of the class so they had actual ?hands-on? experience to take back to their own organizations. The final 2 days of the workshop consisted of field demonstrations of current USGS water-quality sample-collection methods. The hands-on training ensured that attendees were exposed to and experienced proper sampling procedures. Attendees learned integrated-flow techniques during sample collection, field-property documentation, and discharge measurements and calculations. They also used enclosed chambers for sample processing and collected quality-assurance samples to verify their techniques. Benefits of integrated water-quality sample-collection methods are varied. Tribal environmental programs now have the ability to collect data that are comparable across watersheds. The use of consistent sample collection, manipulation, and storage techniques will provide consistent quality data that will enhance the understanding of local water resources. The improved data quality also will help the USEPA better document the condition of the region?s water. Ultimately, these workshops equipped tribes to use uniform sampling methods and to provide consistent quality data that are comparable across the region.

Fact Sheet↗