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At least 253 records · Page 14Linked to original sources
USGS1991

Lead toxicosis in tundra swans near a mining and smelting complex in northern Idaho

Die-offs of waterfowl have occurred in the Coeur d'Alene River system in northern Idaho since at least the early 1900's. We investigated causes of mortality and lead and cadmium contamination of 46 tundra swans ( Cygnus columbianus ) from 1987 to 1989; an additional 22 swans found dead in 1990 were not examined. We necropsied 43 of the 46 birds found from 1987 to 1989; 38 of these were from the Coeur d'Alene River system, which has been contaminated with mining and smelting wastes for a century, and the other 5 were from a nearby, relatively uncontaminated area. Of the 36 livers of swans from the contaminated area that were analyzed, 32 contained lethal levels of lead (6 to 40 μg/g, wet weight) and all birds exhibited several symptoms of lead poisoning, notably enlarged gall bladders containing viscous, dark-green bile. Only 13% of the lead-poisoned birds (10% when data were included from other studies of swans in the area) contained shot, compared to 95% of lead-poisoned swans in studies outside northern Idaho. Lead concentrations in blood samples from 16 apparently healthy swans (0.5 to 2.3 μg/g, and 4 lead-poisoned birds found moribund (1.3 to 9.6 μg/g) indicated that tundra swans accumulated high levels of lead from ingestion of sediment that contained up to 8,700 μg/g of lead and plants that contained up to 400 μg/g. The swans spend only a few weeks in the area staging during the spring migration. The five tundra swans from the uncontaminated area had low levels of lead and essentially no symptoms of lead poisoning. Based on the conventional standard of 0.5 μg/g in whole blood as an indicator of lead poisoning, all of the swans in the Coeur d'Alene River system were either lead-poisoned or at risk of developing plumbism.

Idaho↗
USGS2003

Leaching, transport, and methylation of mercury in and around abandoned mercury mines in the Humboldt River basin and surrounding areas, Nevada

Mercury and methylmercury concentrations were measured in mine wastes, stream sediments, and stream waters collected both proximal and distal from abandoned mercury mines to evaluate mercury contamination and mercury methylation in the Humboldt River system. The climate in the study area is arid, and due to the lack of mine-water runoff, water-leaching laboratory experiments were used to evaluate the potential of mine wastes to release mercury. Mine-waste calcine contains mercury concentrations as high as 14,000 µg/g. Stream-sediment samples collected within 1 km of the mercury mines studied contain mercury concentrations as high as 170 µg/g, but sediments collected from the Humboldt River and regional baseline sites have much lower mercury contents, less than 0.44 µg/g. Similarly, methylmercury concentrations in mine-waste calcine are locally as high as 96 ng/g, but methylmercury contents in stream sediments collected downstream from the mines and from the Humboldt River are lower (<0.05–0.95 ng/g). Stream-water samples collected below two mines studied contain mercury concentrations ranging from 6 to 2,000 ng/L, whereas mercury contents in Humboldt River and Rye Patch Reservoir water were generally lower, ranging from 2.1 to 9.0 ng/L. Methylmercury concentrations in Humboldt River system water were the lowest in this study (<0.02– 0.27 ng/L). Although mercury and methylmercury concentrations were elevated in some mine-waste calcine and mercury concentrations were locally high in mine-waste leachate samples, data show significant dilution of mercury and lower mercury methylation down gradient from the mines, especially in the sediments and water collected from the Humboldt River, which is more than 8 km from any mercury mines. Data show only minor, local transference of mercury and methylmercury from mine-waste calcine to stream sediment, and then onto the water column, and indicate little transference of mercury from the mine sites to the Humboldt River system.

Nevada↗
USGS2007

Southern California Bight 2003 Regional Monitoring Program: V. water quality

More than $30 million is expended annually on environmental monitoring in the Southern California Bight (SCB), yet only 5% of the Bight is monitored on an ongoing basis. Therefore, environmental managers in the SCB decided to expand their monitoring program and, starting in 1994, decided to conduct periodic regional assessments of ecosystem condition and assess the overall health of the SCB. Sixty-five different organizations collaborated in 2003 to create the third SCB Regional Monitoring Program (Bight '03). Bight '03 was designed to be integrated regional monitoring program that encompasses regulatory, academic, and non-governmental agencies. Bight '03 had three components: Coastal Ecology, Shoreline Microbiology, and Water Quality. This report addresses the purpose, approach, findings, and recommendations from the Water Quality component, which focused on contamination-laden stormwater runoff, in particularly its variability in time and space as well as its short-term ecological impacts. Specifically, the Bight '03 Water Quality component had three primary goals, the first of which was to described the temporal evolution of stormwater plumes produced by the major southern California rivers. Specifically, the study was intended to determine how far offshore the plumes extended, how rapidly they advected, how long before the plumes dispersed and how these properties differed among storms and river systems. The second goal was to describe how the physical properties (e.g., turbidity, temperature, salinity) of the plume related to biogeochemical and ecological properties that are of more direct concern to the water quality management community. Accomplished primarily through ship-based sampling of water quality parameters, this second goal was to describe how far offshore, and for how ;long after the storm, elevated bacterial concentrations, toxicity, and nutrients could be detected. Similar to the fist goal, the study also addressed how these answers differed among storms and river systems. The final goal was to determine whether relationships between environmental indicators derived from coincident satellite remote sensing and in situ data sets are sufficiently robust for remote sensing to become a routine water quality monitoring programs. Remote sensing data potentially provide coastal managers with synoptic near-real time regional information about prevailing ocean conditions and hazards that would complement existing field-based sampling protocols, but only if there is a thorough understanding of how to interpret and utilize the proxy measures, such as ocean color. The understanding of these priorities through Bight '03 sampling is intended to provide the basis for developing more efficient, widespread and coast-effective coastal ocean monitoring techniques. Water quality data were collected across eight major river systems within four geographic regions of southern California. Field measurements included the primary contaminants of interest, i.e., bacterial concentrations, water toxicity, and nutrients, as well as related parameters such as temperatures, salinity, total suspended solids, transmissivity, chlorophyll, and colored dissolved organic material (CDOM) concentrations. For each of the four major regions, i.e., Santa Clara/Ventura Rivers, Ballona Creek/Santa Monica Bay, San Pedro Shelf, and the San Diego, Tijuana Rivers, two stormwater events were sampled for up to three days by ship resulting in 574 water column CTD+ profiles and 705 discrete water samples during 36 ship-days. These data were analyzed in combination with MODIS ocean color satellite remote sensing, buoy meteorological observations, drifters, and HF radar current measurements to evaluate the dispersal patterns, dynamics, and impacts of the freshwater runoff plumes. Based on these data and resulting analyses, the principal conclusions were as follow: - Stormwater runoff turbidity plumes were found to be spatially extensive, covering up to 2500 km 2 within the Southern California Bight nearshore zone, and persisting over the entire duration of the post-storm sampling period (at least 3 days). - The spatial and temporal extent of the portion of the plume with contaminants was far less than that of the turbidity plume, typically representing <10% of its area (30-70% off Tijuana); however, with contaminant impacts generally greatly reduced or absent by the third or fourth day of sampling - Pseudo-nitzschia , a harmful algae that produces domoic acid, was found to be more abundant than previously reported. - Accurately describing stormwater runoff plumes requires a combination of in situ and remote sensing assessment tools, with satellite data providing valuable synoptic information. From these conclusions, the following recommendations are provided: - Future studies designed to describe stormwater plumes should include a combination of ship - and remote sensing-based methods. - CDOM is a good proxy of the freshwater runoff plume and should be added as a standard measurement parameter on water quality instrument packages. - Investigations are needed that assess on a local basis the spatial extent of ecological effects of stormwater plumes early in the storm, ideally accompanied by airborne imagery to provide improved temporal & spatial resolution, to fill in knowledge gaps. The next Bight regional monitoring program should focus on quantifying nutrient loadings and dynamics in association with stormwater runoff and other sources, and characterize their attendant ecosystem impacts such as phytoplankton blooms.

California↗
USGS1987

Use of low-altitude aerial photography to identify submersed aquatic macrophytes

The feasibility of using low-altitude aerial photography to identify beds of submersed macrophytes is demonstrated. True color aerial photos and collateral ground survey information for submersed aquatic macrophyte beds at 10 sites in the St.Clair-Detroit River system were obtained in September 1978. Using the photos and collateral ground survey information, a dichotomous key was developed for the identification of six classes - beds of five genera of macrophytes and one substrate type. A test was prepared to determine how accurately photo interpreters could identify the six classes. The test required an interpreter to examine an unlabeled, outlined area on photographs and identify it using the key. Six interpreters were tested. One pair of interpreters was trained in the interpretation of a variety of aerial photos, a second pair had field experience in the collection and identification of submersed macrophytes in the river system, and a third pair had neither training in the interpretation of aerial photos nor field experience. The criteria that we developed were applied equally well by the interpretors, regardless of their training or experience. Overall accuracy (i.e., omission errors) of all six classes combined was 68% correct, whereas, overall accuracy of individual classes ranged from 50 to 100% correct. Mapping accuracy (i.e. omission and commission errors) of individual classes ranged from 36 to 75%. Although the key developed for this study has only limited application outside the context of the data and sites examined in this study, it is concluded that low-altitude aerial photography, together with limited amounts of collateral ground survey information, can be used to economically identify beds of submersed macrophytes in the St. Clair-Detroit River system and other similar water bodies.

Conference Paper↗
USGS2011

Effects of recreational flow releases on natural resources of the Indian and Hudson Rivers in the Central Adirondack Mountains, New York, 2004-06

The U.S. Geological Survey (USGS), the New York State Department of Environmental Conservation (NYSDEC), and Cornell University carried out a cooperative 2-year study from the fall of 2004 through the fall of 2006 to characterize the potential effects of recreational-flow releases from Lake Abanakee on natural resources in the Indian and Hudson Rivers. Researchers gathered baseline information on hydrology, temperature, habitat, nearshore wetlands, and macroinvertebrate and fish communities and assessed the behavior and thermoregulation of stocked brown trout in study reaches from both rivers and from a control river. The effects of recreational-flow releases (releases) were assessed by comparing data from affected reaches with data from the same reaches during nonrelease days, control reaches in a nearby run-of-the-river system (the Cedar River), and one reach in the Hudson River upstream from the confluence with the Indian River. A streamgage downstream from Lake Abanakee transmitted data by satellite from November 2004 to November 2006; these data were used as the basis for developing a rating curve that was used to estimate discharges for the study period. River habitat at most study reaches was delineated by using Global Positioning System and ArcMap software on a handheld computer, and wetlands were mapped by ground-based measurements of length, width, and areal density. River temperature in the Indian and Hudson Rivers was monitored continuously at eight sites during June through September of 2005 and 2006; temperature was mapped in 2005 by remote imaging made possible through collaboration with the Rochester Institute of Technology. Fish communities at all study reaches were surveyed and characterized through quantitative, nearshore electrofishing surveys. Macroinvertebrate communities in all study reaches were sampled using the traveling-kick method and characterized using standard indices. Radio telemetry was used to track the movement and persistence of stocked brown trout (implanted with temperature-sensitive transmitters) in the Indian and Hudson Rivers during the summer of 2005 and in all three rivers during the summer of 2006. The releases had little effect on river temperatures, but increased discharges by about one order of magnitude. Regardless of the releases, river temperatures at all study sites commonly exceeded the threshold known to be stressful to brown trout. At most sites, mean and median water temperatures on release days were not significantly different, or slightly lower, than water temperatures on nonrelease days. Most differences were very small and, thus, were probably not biologically meaningful. The releases generally increased the total surface area of fast-water habitat (rapids, runs, and riffles) and decreased the total surface area of slow-water habitat (pools, glides, backwater areas, and side channels). The total surface areas of wetlands bordering the Indian River were substantially smaller than the surface areas bordering the Cedar River; however, no channel geomorphology or watershed soil and topographic data were assessed to determine whether the releases or other factors were mainly responsible for observed differences. Results from surveys of resident biota indicate that the releases generally had a limited effect on fish and macroinvertebrate communities in the Indian River and had no effect on communities in the Hudson River. Compared to fish data from Cedar River control sites, the impoundment appeared to reduce total density, biomass, and richness in the Indian River at the first site downstream from Lake Abanakee, moderately reduce the indexes at the other two sites on the Indian River, and slightly reduce the indexes at the first Hudson River site downstream from the confluence with the Indian River. The densities of individual fish populations at all Indian River sites were also reduced, but related effects on fish populations in the Hudson River were less evident. Altho

Scientific Investigations Report↗
USGS2014

Developing and testing temperature models for regulated systems: a case study on the Upper Delaware River

Water temperature is an important driver of many processes in riverine ecosystems. If reservoirs are present, their releases can greatly influence downstream water temperatures. Models are important tools in understanding the influence these releases may have on the thermal regimes of downstream rivers. In this study, we developed and tested a suite of models to predict river temperature at a location downstream of two reservoirs in the Upper Delaware River (USA), a section of river that is managed to support a world-class coldwater fishery. Three empirical models were tested, including a Generalized Least Squares Model with a cosine trend (GLScos), AutoRegressive Integrated Moving Average (ARIMA), and Artificial Neural Network (ANN). We also tested one mechanistic Heat Flux Model (HFM) that was based on energy gain and loss. Predictor variables used in model development included climate data (e.g., solar radiation, wind speed, etc.) collected from a nearby weather station and temperature and hydrologic data from upstream U.S. Geological Survey gages. Models were developed with a training dataset that consisted of data from 2008 to 2011; they were then independently validated with a test dataset from 2012. Model accuracy was evaluated using root mean square error (RMSE), Nash Sutcliffe efficiency (NSE), percent bias (PBIAS), and index of agreement (d) statistics. Model forecast success was evaluated using baseline-modified prime index of agreement (md) at the one, three, and five day predictions. All five models accurately predicted daily mean river temperature across the entire training dataset (RMSE = 0.58–1.311, NSE = 0.99–0.97, d = 0.98–0.99); ARIMA was most accurate (RMSE = 0.57, NSE = 0.99), but each model, other than ARIMA, showed short periods of under- or over-predicting observed warmer temperatures. For the training dataset, all models besides ARIMA had overestimation bias (PBIAS = −0.10 to −1.30). Validation analyses showed all models performed well; the HFM model was the most accurate compared other models (RMSE = 0.92, both NSE = 0.98, d = 0.99) and the ARIMA model was least accurate (RMSE = 2.06, NSE = 0.92, d = 0.98); however, all models had an overestimation bias (PBIAS = −4.1 to −10.20). Aside from the one day forecast ARIMA model (md = 0.53), all models forecasted fairly well at the one, three, and five day forecasts (md = 0.77–0.96). Overall, we were successful in developing models predicting daily mean temperature across a broad range of temperatures. These models, specifically the GLScos, ANN, and HFM, may serve as important tools for predicting conditions and managing thermal releases in regulated river systems such as the Delaware River. Further model development may be important in customizing predictions for particular biological or ecological needs, or for particular temporal or spatial scales.

Delaware, New York, Pennsylvania↗
USGS2003

Vegetation, soil, and flooding relationships in a blackwater floodplain forest

Hydroperiod is considered the primary determinant of plant species distribution in temperate floodplain forests, but most studies have focused on alluvial (sediment-laden) river systems. Few studies have evaluated plant community relationships in blackwater river systems of the South Atlantic Coastal Plain of North America. In this study, we characterized the soils, hydroperiod, and vegetation communities and evaluated relationships between the physical and chemical environment and plant community structure on the floodplain of the Coosawhatchie River, a blackwater river in South Carolina, USA. The soils were similar to previous descriptions of blackwater floodplain soils but had greater soil N and P availability, substantially greater clay content, and lower soil silt content than was previously reported for other blackwater river floodplains. Results of a cluster analysis showed there were five forest communities on the site, and both short-term (4 years) and long-term (50 years) flooding records documented a flooding gradient: water tupelo community > swamp tupelo > laurel oak = overcup oak > mixed oak. The long-term hydrologic record showed that the floodplain has flooded less frequently from 1994 to present than in previous decades. Detrended correspondence analysis of environmental and relative basal area values showed that 27% of the variation in overstory community structure could be explained by the first two axes; however, fitting the species distributions to the DCA axes using Gaussian regression explained 67% of the variation. Axes were correlated with elevation (flooding intensity) and soil characteristics related to rooting volume and cation nutrient availability. Our study suggests that flooding is the major factor affecting community structure, but soil characteristics also may be factors in community structure in blackwater systems. ?? 2003, The Society of Wetland Scientists.

Wetlands↗
USGS2024

Use of otolith microchemistry to determine natal origin for Silver Carp Hypophthalmichthys molitrix in the lower Mississippi River basin

Silver Carp ( Hypophthalmichthys molitrix ) populations have established and expanded throughout the lower Mississippi River basin (LMRB). Information pertaining to Silver Carp population mixing among rivers within the LMRB is lacking. Documented relations between Silver Carp otolith and river water barium (Ba) and strontium (Sr) microchemical signatures may enable estimation of origins of Silver Carp in the LMRB. Replicate water samples and otoliths from 308 Silver Carp were collected from the Cache, Arkansas, White, Yazoo, St. Francis, L’Anguille, and Mississippi rivers, and Merrisach Lake (situated along a canal connecting the lower reaches of the Arkansas and White rivers) within the LMRB. Water and carp otolith microchemical signatures exhibited consistent differences among water bodies. A classification and regression tree model exhibited 80% accuracy when assigning carp collected from the White, Arkansas, and Mississippi rivers based on fish-water microchemical signatures. Model accuracy decreased as smaller rivers were incorporated into models. Predicted natal origin based on otolith microchemical signatures suggested the White River (43%) and the lower Mississippi River (39%) were the likely origins for ~ 82% of the Silver Carp sampled. Despite the prevalence of adult Silver Carp within the Arkansas River system, fewer (18%) appeared to have originated there compared to the White and Mississippi rivers. Long-term water sampling and additional isotopic measurements may refine analyses to better determine the relative contributions of Silver Carp from the smaller river systems. Population mixing of Silver Carp among tributary rivers appears to be common within the LMRB, and removal efforts may benefit from evaluating the magnitude of fish movement and connectivity among rivers.

lower Mississippi River basin↗
USGS1995

Ground Water Atlas of the United States: Segment 2, Arizona, Colorado, New Mexico, Utah

This chapter of the Ground Water Atlas of the United States describes the aquifers in Arizona, Colorado, New Mexico, and Utah. These four States, which comprise Segment 2 of this Atlas, are located in the Southwestern United States and extend from the rolling grasslands of the Great Plains on the east across the Rocky Mountains and Continental Divide to the desert basins of the Southwest. The 425,000-square-mile area ranges in altitude from about 14,400 feet above sea level in the Rocky Mountains of Colorado to about 100 feet near the lower Colorado River in southwestern Arizona. All the ground water in Segment 2 ultimately is derived from infiltration of precipitation, which varies considerably with the altitude and topography of the area. The Great Plains Physiographic Province of the Central United States extends into eastern Colorado and New Mexico (fig. 1), where flat to rolling prairie (fig. 2) with scattered hills and bluffs gradually rises westward to 5,000 to 7,000 feet above sea level and abruptly gives way to the frontal ranges of the Rocky Mountains in the Southern Rocky Mountain and Basin and Range Physiographic Provinces. West of the frontal ranges in Colorado and northern New Mexico are additional and higher mountain ranges generally oriented north-south but with many spurs and extensions oriented in other directions. The many ranges of the Rocky Mountains are separated by valleys and high mountain parks (fig. 3). Colorado contains about three-fourths of the Nation's land area above 10,000 feet and has 53 mountain peaks higher than 14,000 feet. Most of these high peaks are located near the Continental Divide (fig. 1), which extends approximately north-south through central Colorado and western New Mexico. The altitude of the divide decreases in southern New Mexico to less than 4,500 feet in a few areas. Farther westward, the mountains are less prevalent and are interspersed with broad structural basins. These basins and the broad valleys of the middle Colorado River and its tributaries form the irregular intermontane topography of the Colorado Plateaus Physiographic Province (fig. 4). Plateaus and high mesas are formed where the surface has been dissected by rugged canyons carved by the Colorado River and its tributaries (fig. 5). The largest of these canyons-the Grand Canyon-extends about 220 miles southwestward from the mouth of the Little Colorado River in Arizona and ranges from 4 to 18 miles in width and from 2,700 to 5,700 feet in depth below the rim. Small mountain ranges and intervening broad desert valleys of the Basin and Range Physiographic Province are prevalent to the west and south of the Colorado Plateaus in western Utah, southern Arizona, and southern New Mexico (fig. 1). These mountain ranges generally protrude 3,000 to 6,000 feet above the surrounding valley floor (fig. 6) and commonly extend from 20 to 50 miles in a north or northwesterly direction. Small parts of the Middle Rocky Mountains and Wyoming Basin Physiographic Provinces extend into northwestern Colorado and northeastern Utah (fig. 1). The topography, geology, and hydrology of the two areas are described in Chapter 1 of this Atlas. Four of the Nation's major river systems have headwaters in the mountainous areas of Segment 2. The South Platte River of the Missouri River system drains the eastern slope of northern Colorado; the Arkansas River and its tributary, the Canadian River, drain southeastern Colorado and northeastern New Mexico; the Rio Grande and its tributary, the Pecos River, drain south-central Colorado and central New Mexico; and the Colorado River and its tributaries drain Arizona, eastern Utah, Northwestern New Mexico, and western Colorado (fig. 1). Western Utah is drained by numerous streams that terminate in local desert basins, the Great Salt Lake, or other local lakes and reservoirs. Because the Great Salt Lake lies in the Great Basin, which is the largest closed basin in North America, it has no outlet to the sea. The salinity of the lake water is about 20 percent or about 6 times the salinity of seawater. Most of Segment 2 is sparsely populated. The average population density of counties is less than 8 persons per square mile in about 65 percent of the four-State area (fig. 7). Population densities range from less than 0.5 person per square mile in a few rural counties to more than 4 ,000 persons per square mile in populous urban areas. The 1990 population of the four States was about 10 million; almost 70 percent of this population was in Arizona and Colorado. Most land in Segment 2 is undeveloped forest grassland, or desert shrubland, much of which is used for livestock grazing. Land used for production of commercial crops primarily is in eastern Colorado and eastern New Mexico.

Arizona, Colorado, New Mexico, Utah↗
USGS2018

Large-scale variation in density of an aquatic ecosystem indicator species

Monitoring indicator species is a pragmatic approach to natural resource assessments, especially when the link between the indicator species and ecosystem state is well justified. However, conducting ecosystem assessments over representative spatial scales that are insensitive to local heterogeneity is challenging. We examine the link between polychlorinated biphenyl (PCB) contamination and population density of an aquatic habitat specialist over a large spatial scale using non-invasive genetic spatial capture-recapture. Using American mink (Neovison vison), a predatory mammal and an indicator of aquatic ecosystems, we compared estimates of density in two major river systems, one with extremely high levels of PCB contamination (Hudson River), and a hydrologically independent river with lower PCB levels (Mohawk River). Our work supports the hypothesis that the mink densities are substantially (1.64-1.67 times) lower in the contaminated river system. We demonstrate the value of coupling the indicator species concept with well-conceived and spatially representative monitoring protocols. PCBs have demonstrable detrimental effects on aquatic ecosystems, including mink, and these effects are likely to be profound and long-lasting, manifesting as population-level impacts. Through integrating non-invasive data collection, genetic analysis, and spatial capture-recapture methods, we present a monitoring framework for generating robust density estimates across large spatial scales.

New York↗
USGS2011

Dispersal and dam passage of sonic-tagged juvenile lake sturgeon in the upper Tennessee River

More than 90,000 state-endangered lake sturgeon (Acipenser fulvescens) have been stocked into the French Broad River, Holston River, and Fort Loudoun Lake in the upper Tennessee River system. Although incidental reports of anglers catching these fish have increased, little is known about their fate after stocking. Therefore, this study was conducted to evaluate lake sturgeon dispersal throughout the system. Seven submersible ultrasonic receivers were deployed in the upper Tennessee River system and 37 juvenile fish (mean fork length = 660 mm) were surgically implanted with ultrasonic transmitters in the fall of 2007. These fish were stocked at two sites in the headwaters of Fort Loudoun Lake. The receivers logged 1,345 detections of tagged fish and manual tracking located 32 of the 37 tagged lake sturgeon over 21 months. Ten (31%) tagged fish passed through Fort Loudoun Dam and were located downstream in the headwaters of Watts Bar Reservoir; the other tagged fish were still at large above Fort Loudoun Dam when tracking ceased in 2009. Of all fish stocked, three (9%) were last located in the French Broad River and none were located in the Holston River.

Tennessee↗
USGS1998

Concepts for monitoring water quality in the Spokane River Basin, northern Idaho and eastern Washington

Numerous environmental studies have been conducted in the Spokane River Basin over the past several decades by government agencies, academic institutions, and environmental engineering firms. Most of these efforts have focused on the environmental effects of more than a century of silver, lead, and zinc mining and oreprocessing activities in the South Fork Coeur d'Alene River valley in northern Idaho. Several studies also have assessed the water quality and potential for eutrophication of Coeur d'Alene and Long Lakes and the Coeur d'Alene, St. Joe, and Spokane Rivers. Because past investigations often were limited in scope and employed different approaches and methods, an integrated understanding of hydrologic, water-quality, and aquatic biological conditions still is lacking for the basin as a whole. Substantial resources are being spent for water-quality and naturalresource management, and for mitigating the adverse environmental effects of past mining activities in the basin. A water-quality monitoring network, integrated with the decision-making processes associated with these efforts, could be of considerable value. The purpose of such a monitoring network is to produce high-quality information on which to base sound water-quality and natural-resource management decisions and to assess the effectiveness of those decisions. A streamflow- and water-quality monitoring infrastructure already exists in the Spokane River Basin. This infrastructure consists of 20 lake-stage and streamflow-gaging stations, representing specific drainages or subdrainages and, in many cases, specific stream reaches or subreaches. These gaging stations are operated by the U.S. Geological Survey (USGS), several of them in cooperation with State and Federal agencies and a private utility company. Extensive streamflow data are available, some dating from the late 1800s. Water-quality data are also available from recent USGS cooperative studies in the Coeur d'Alene Lake watershed. A nutrient load/lake response (eutrophication) model has been developed for Coeur d'Alene Lake. Hydraulic models for estimating streamflow through the low-gradient reaches of the Coeur d'Alene and St. Joe Rivers have been developed. Trace-element concentrations and distributions in sediments in the lower South Fork and main-stem Coeur d'Alene River flood plain and the bed of Coeur d'Alene Lake have been assessed. Trace-element transport models have been developed for the lower Coeur d'Alene River system; estimates of annual load are available from the early 1990's to the present (1998). The USGS is monitoring traceelement concentrations and transport at seven gaging stations in the lower Coeur d'Alene River system and upper Spokane River, in cooperation with the U.S. Environmental Protection Agency. Fish and macroinvertebrate community assessment and tissue contaminant analyses at four Coeur d'Alene and St. Joe River gaging stations will begin in 1998, either as part of the Idaho Surface- Water Quality Ambient Monitoring Network operated by USGS in cooperation with the Idaho Division of Environmental Quality, or for the Northern Rockies Intermontane Basins (NROK) study of the USGS National Water-Quality Assessment (NAWQA) Program. Several gaging stations in the Spokane River Basin are being considered for routine sampling sites for the NROK NAWQA study. Several other sites also will be sampled for contaminants in bed sediment and fish tissue for the NROK study. Combined with appropriate sampling and data interpretation strategies, the existing USGS gaging-station network and data base could provide integrated water-quality information needed for sound environmental and resource-management decisions throughout the Spokane River Basin.

Idaho;Washington↗
USGS1994

Stratigraphy of the Mississippi-Alabama shelf and the Mobile River incised-valley system

The Mobile River incised-valley system located in the northern Gulf of Mexico occupies an area from southern Alabama through Mobile Bay to the outer Mississippi-Alabama continental shelf. During the Wisconsinan regression, this incised-valley system was fluvially eroded and extended across the exposed shelf to a shelf-margin delta complex. The last postglacial transgression drowned the entrenched alluvial valleys and reworked the alluvial fill and estuarine deposits to form shoals on the middle shelf. As the postglacial transgression slowed. Mobile Bay was formed. Mobile Bay is a large estuarine system protected by barrier islands. This paper documents the late Quaternary history of the Mobile River incised valley and fill. Mobile Bay is a large (> 1000 km 2 ) microtidal estuary in southern Alabama that receives drainage through the Mobile River system. The Mobile River catchment is the fourth largest in the United States and terminates at the bayhead delta of Mobile Bay. The bay is a classic example of a wave-dominated, drowned, fluvial incised valley. During the middle-late Wisconsinan, glacial maximum, relative sea level was approximately 120 m lower than present. The Mobile River incised valley was a conduit for drainage from the catchment to the shelf margin. The sediment carried by the fluvial system during this lowstand passed through the Mobile River incised valley, across the exposed shelf and was deposited on the shelf margin as deltaic lobes. Rapid sea-level rise forced coastal-plain shorelines landward across the present mid-continental shelf. Transgression of the estuary mouth left a series of estuary-mouth-bar deposits that were reworked and overlie alluvial fill. These sand-rich deposits were submerged by the continuing transgression and reworked to form shoals As the Holocene sea-level rise slowed, the Mobile River incised valley became an estuarine depocenter. In the present alluvial valley, lowstand deposits are overlain by estuarine sediments deposited during the initial flooding of the valley and subsequent formation of Mobile Bay. During the present highstand, longshore sediment transport formed a spit across much of the bay mouth, creating a restricted estuary into which a bayhead delta has prograded. Late Holocene deposits in Mobile Bay consists predominantly or lagoonal sediments with bayhead-delta deposits encroaching into the northern end of the bay. The Holocene incised-valley fill (estuarine facies) underlying Mobile Buy fit well into the conceptual facies model of a microtidal wave-dominated estuary. The model does not fit as well, however, with the rapidly transgressed shelf portion of the incised valley. The down dip section does not contain a clearly identifiable (from seismic profiles) estuarine facies; the valley fill is primarily fluvial and is overlain by marine shoals. In the Mobile River incised valley, the distal portion of the valley was rapidly drowned, allowing the thin estuarine facies to be reworked. The proximal portion was drowned more slowly, leaving the estuarine facies intact. Thus, the single incised valley contains two very different types of fill.

Alabama↗
USGS2014

Methylmercury-induced changes in gene transcription associated with neuroendocrine disruption in largemouth bass (Micropterus salmoides)

Methyl-mercury (MeHg) is a potent neuroendocrine disruptor that impairs reproductive processes in fish. The objectives of this study were to (1) characterize transcriptomic changes induced by MeHg exposure in the female largemouth bass (LMB) hypothalamus under controlled laboratory conditions, (2) investigate the health and reproductive impacts of MeHg exposure on male and female largemouth bass (LMB) in the natural environment, and (3) identify MeHg-associated gene expression patterns in whole brain of female LMB from MeHg-contaminated habitats. The laboratory experiment was a single injection of 2.5 μg MeHg/g body weight for 96 h exposure. The field survey compared river systems in Florida, USA with comparably lower concentrations of MeHg (Wekiva, Santa Fe, and St. Johns Rivers) in fish and one river system with LMB that contained elevated concentrations of MeHg (St. Marys River). Microarray analysis was used to quantify transcriptomic responses to MeHg exposure. Although fish at the high-MeHg site did not show overt health or reproductive impairment, there were MeHg-responsive genes and pathways identified in the laboratory study that were also altered in fish from the high-MeHg site relative to fish at the low-MeHg sites. Gene network analysis suggested that MeHg regulated the expression targets of neuropeptide receptor and steroid signaling, as well as structural components of the cell. Disease-associated gene networks related to MeHg exposure, based upon expression data, included cerebellum ataxia, movement disorders, and hypercalcemia. Gene responses in the CNS are consistent with the documented neurotoxicological and neuroendocrine disrupting effects of MeHg in vertebrates.

General and Comparative Endocrinology↗
USGS1994

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Owyhee and Vale Projects, Oregon and Idaho, 1990-91

A reconnaissance investigation was conducted during 1990--91 in the Owyhee and Vale projects in eastern Oregon and southwestern Idaho, as well as at a number of sites in the Snake River and tributaries to the Snake River in the area of study. The objective of the study was to determine if agricultural drainwater entering the study area was causing, or had the potential to cause, significant harmful effects to human health, fish and wildlife, or may adversely affect the suitability of water for beneficial uses. Approximately 153,000 acres of land are irrigated annually within the areas of the Owyhee and Vale projects. Large quantities of water are required because of the semiarid climate and relatively high evaporation rates. Several reservoirs in the area are filled annually during the wet, nonirrigation season to sustain irrigation during the dry summer months. During the irrigation season, this impounded water, along with direct diversions from the Malheur, Owyhee, and Snake Rivers, is transported to the irrigated areas through a series of diversion tunnels, siphons, canals, aqueducts, ditches, and drains. Major crops grown in the area include sugar beets, alfalfa hay and other hay crops, onions, and winter wheat. Minor crops include corn, potatoes, mint, various seed crops, and fruit. In 1987, it was estimated that the following amounts of pesticides were used in the project areas: 2,4-D (21,000 lbs [pounds]), chlorpyrifos (1,000 lbs), dacthal (40,000 lbs), dicamba (320 lbs), endosulfan (2,500 lbs), ethion (11,000 lbs), malathion (24,000 lbs), parathion (5,000 lbs), and phorate (11,000 lbs). Median concentrations and values for total dissolved solids, alkalinity, sodium adsorption ratio, and hardness in the Vale project area were greater than 1.5 times those values observed in the Owyhee project area or at other Snake River locations. During irrigation (August 1990), total dissolved solids, alkalinity, sodium adsorption ratio, and hardness values increased in a downstream manner. Constituent values at drainwater sites generally were comparable to concentrations below the irrigated ureas in the Owyhee and Vale project areas. The trace elements arsenic, boron, copper, molybdenum, vanadium, and zinc were detected in most water samples; cadmium, chromium, lead, and selenium were detected in some samples at concentrations generally near the analytical reporting limit; mercury was not detected in any samples. In some water samples, concentrations of arsenic, boron, cadmium, copper, and lead exceeded State or Federal water-quality standards or criteria. Most trace elements in bottom sediment were detected at concentrations within the expected 95-percent baseline range for soils from the Western United States. Concentrations that exceeded the 95-percent baseline range for study area soils were: (1) arsenic and lead in one sample from a site in the Vale project area; (2) mercury, lead, and tin in one sample from a site in the Snake River system; (3) manganese in two samples from two sites in the Snake River system; and (4) manganese from one sample from a site in the Vale project area. Fifteen pesticides and metabolites were detected in whole-water samples collected from sites in the study area. DDT, plus its metabolites (DDE and DDD), dieldrin, endrin, 2,4-D, dicamba, and dacthal were detected in samples collected from seven or more sites. Other pesticides detected included chlorpyrifos, endosulfan, ethion, malathion, parathion, phorate, and lindane. Most of the detected pesticide concentrations generally were largest in drainwater and at the most downstream sampling locations in the Owyhee and Vale project areas. Concentrations exceeded water-quality criteria established for the protection of freshwater aquatic life in 86 percent of the whole-water samples analyzed for DDT plus its metabolites, 71 percent of the dieldrin samples, 14 percent of the endrin samples, and 10 percent of the parathion samples. Eight pesticides and

Water-Resources Investigations Report↗
USGS2021

Stream classification and gravel-bar inventory for Buffalo National River and Ozark National Scenic Riverways

The data summarized in this report provide a baseline characterization of the physical attributes of the riverine ecosystems in two landscapes managed by the National Park Service—Ozark National Scenic Riverways, Missouri, and Buffalo National River, Arkansas—to inform understanding and management of aquatic habitat. The study utilized a basin-scale approach and consisted of two components: a basin-scale channel classification and a longitudinal inventory of gravel bars. We evaluated the Jacks Fork and Current River in Ozark National Scenic Riverways and the main stem Buffalo River in Buffalo National River. The primary objective of the study was to characterize geomorphic patterns that affect channel stability and rates of geomorphic change in both national park units. Findings may be used to inform understanding of the distribution and availability of aquatic habitat. For the basin-scale channel classification, we performed exploratory statistical analyses using nine geomorphic variables (channel width, standard deviation in channel width, valley width, distance to valley wall, confinement, bar area, bluff area, braid index, and sinuosity). Each metric was quantified along the length of the river system at 200-meter intervals. We then performed a cluster analysis for each river using a subset of variables, resulting in 2 to 5 distinct geomorphic classes depending on criteria used for determining number of clusters. Longitudinal patterns in clusters vary for each river system but reflect a combination of landscape factors including valley width, influence of tributaries, and lithology, which affect channel stability and aquatic habitat. We developed a longitudinal inventory of gravel bars by quantifying the area of gravel bars from a series of imagery in each park. In Ozark National Scenic Riverways we analyzed five time periods, with the earliest being 1992 and most recent being 2014. In Buffalo National River, we also analyzed five series of aerial imagery, ranging from 1982 to 2013. The analysis indicated a general decrease in gravel storage in upstream reaches of each river evaluated, accompanied by a general increase in storage farther downstream. Local patterns in gravel-bar area are associated with longitudinal patterns in geomorphic setting, such as valley geometry and channel width, that affect depositional patterns and sediment storage at the reach scale.

Arkansas, Missouri↗
USGS2018

The Colorado River and its deposits downstream from Grand Canyon in Arizona, California, and Nevada

Understanding the evolution of the Colorado River system has direct implications for (1) the processes and timing of continental-scale river system integration, (2) the formation of iconic landscapes like those in and around Grand Canyon, and (3) the availability of groundwater resources. Spatial patterns in the position and type of Colorado River deposits, only discernible through geologic mapping, can be used to test models related to Colorado River evolution. This is particularly true downstream from Grand Canyon where ancestral Colorado River deposits are well-exposed. We are principally interested in (1) regional patterns in the minimum and maximum elevation of each depositional unit, which are affected by depositional mechanism and postdepositional deformation; and (2) the volume of each unit, which reflects regional changes in erosion, transport efficiency, and accommodation space. The volume of Colorado River deposits below Grand Canyon has implications for groundwater resources, as the primary regional aquifer there is composed of those deposits. To this end, we are presently mapping Colorado River deposits and compiling and updating older mapping. This preliminary data release shows the current status of our mapping and compilation efforts. We plan to update it at regular intervals in conjunction with ongoing mapping.

Arizona, California, Nevada↗
USGS2011

Movement of saugers in the lower Tennessee River determined by radio telemetry, and implications for management

Since 1979, abundances of sauger Stizostedion canadense have declined in the Tennessee River system. Reasons for this decline may include overharvest, loss of spawning habitat, and low recruitment due to extreme flows. The purpose of this study was to investigate the movements of saugers following winter concentration below Pickwick Dam, Tennessee. Thirty-seven saugers were implanted with radio transmitters directly below Pickwick Dam and were tracked between December 1992 and June 1993. Four saugers moved upstream through the locks at Pickwick Dam: the remaining fish stayed within the first 30 km of the tailwater throughout the spawning season. Three areas below Pickwick Dam were identified as possible March prespawn staging sites. After April 1, saugers in the tailwater area began a rapid downstream migration to the main basin of Kentucky Lake. Some fish moved downstream more than 200 km in less than 10 d in this semiclosed system. Movements encompassed four states (Kentucky, Tennessee, Mississippi, and Alabama) along the Tennessee River system, underscoring the need for interjurisdictional management.

Alabama, Mississippi, Tennessee↗