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At least 1,279 records · Page 71Linked to original sources
USGS2004

Fish and Aquatic Invertebrate Communities in Waterways, and Contaminants in Fish, at the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, 1999-2000

Fish and aquatic invertebrate communities in waterways of the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, were surveyed from 1999 to 2000. An inventory of fish in the Barataria Preserve was established, and concentrations of selected organochlorine pesticides, polychlorinated biphenyls, and trace elements; iron; and manganese in fish tissue for selected species were determined. The fish and aquatic invertebrate sampling completed for this study indicated that abundant and diverse communities are present in the Barataria Preserve. Thirty-two species of fish were identified in the Barataria Preserve during this survey. The total number of species identified in a single sampling ranged from 20 to 26. Most of the fish sampled are designated as intermediate in their tolerance to poor water quality. Three species of fish designated as tolerant (common carp, Cyprinus carpio; golden shiner, Notemigonus crysoleucas; and yellow bullhead, Ameiurus natalis), and one as intolerant (lake chubsucker, Erymizon sucetta), were identified. In November 1999, the average total weight of all fish collected by boat-mounted electroshocker from a single site was about 35,000 grams; in May and July 1999, the average total weight was between 9,000 and 10,000 grams. The contribution of spotted gar (Lepisosteus oculatus) to the total weight of the fish averaged between 38 and 41 percent among the three sample periods. Members of the sunfish family (Centrarchidae) contributed between 18 and 28 percent of the total weight. For each sampling period, 60 to 83 percent of the total weight from the sunfish family was contributed by bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides). Aquatic invertebrates were sampled at three sites. Most aquatic invertebrates identified were freshwater species, but some were brackish-water and marine species. About 234,000 organisms were identified and enumerated from the richest-targeted habitat (RTH, floating rafts of aquatic plants). Individuals from 84 genera belonging to 51 families were identified. Diptera (true flies) was the most diverse group. Malacostraca (crustaceans), especially Amphipoda (scuds and sideswimmers), were the most abundant (36 percent). Total abundance and taxa richness of aquatic invertebrates were comparable during the March and July sampling in 1999, but were lower in samples collected from the same habitat at all three sites in April 2000. About 106 individuals were identified and enumerated from the depositional-targeted habitat (DTH, bottom material). Individuals from 7 genera belonging to 9 families were identified. Diptera was the most diverse group, and Annelida, especially tubificid worms, were the most abundant organisms identified (52 percent). Total abundance and composition of aquatic invertebrate communities differed between RTH and DTH at all three sites in April 2000. Organic compounds in whole fish, and trace elements, iron, and manganese in fillets, were analyzed in bowfin (Amia calva), bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and common carp (Cyprinus carpio). Organic compounds were not detected. Mercury was detected in fillets of all four species. Highest concentrations of mercury were detected in fillets from bowfin and largemouth bass. Mercury concentrations increased with increasing weight in the three predatory fish species (bowfin, bluegill, and largemouth bass), but were much lower, relative to weight, in the omnivore, common carp. Chromium concentrations were detected in tissue of the two larger fish, bowfin and common carp. Cadmium and lead were not detected in any samples. Mercury concentrations for larger predatory fish caught in Preserve waterways may be a concern if the fish are frequently consumed by humans. The process of mercury accumulation appears to be natural, and not related to a local source problem. Mercury concentrations in comparable fish tissue at

Scientific Investigations Report↗
USGS2004

Water flow and nutrient flux from five estuarine rivers along the southwest coast of the Everglades National Park, Florida, 1997-2001

Discharge and nutrient fluxes for five tidally affected streams were monitored and evaluated as a part of the U.S. Geological Survey Place-Based Studies Initiative and the U.S. Department of the Interior Critical Ecosystem Studies Initiative. Locations on Lostmans Creek, and Broad, Harney, Shark, and North Rivers were selected using the criterion that a large amount of the water that flows through Shark River Slough must pass these sites. Discharge and nutrient-concentration data collection started at the Broad, Harney, and Shark River stations in January 1997 and ended in early 2001. Discharge and nutrient-concentration data collection started at the Lostmans Creek and North River stations in April 1999 and ended in early 2001. Each station was equipped with a vertically oriented acoustic-velocity sensor, water-level pressure transducer, bottom water-temperature thermistor, and specific conductance four-electrode sensor. Data collected using a vessel-mounted acoustic discharge measurement system were used to calibrate regression models of the mean river velocities and the in-situ index velocities. Information from these stations, in conjunction with data from other ongoing studies, will help to determine environmental effects on the southwest coast estuaries as changes in water management of the Everglades National Park continue. Discharges from the Lostmans Creek, and Broad, Harney, Shark, and North River stations are influenced by semidiurnal tides, meteorological events, and surface- and ground-water inflow. Each of the five rivers is usually well mixed, having no greater than 500 microSiemens per centimeter at 25? Celsius difference in specific conductance from top to bottom during flood and ebb tides. Instantaneous flood discharges (water moving upstream) are typically of greater magnitude and shorter duration than instantaneous ebb discharges (water moving downstream). Instantaneous discharge data were filtered using a low-pass filter to remove predominant tidal frequencies, and the filtered data were used to compute daily mean and monthly mean residual discharges. Lostmans Creek, and Broad, Harney and Shark Rivers each contributed from 20 to 27 percent of the total measured discharge to the Gulf of Mexico, whereas North River contributed approximately 4 percent. The main discharge region of the Shark River Slough extends from as far north as Lostmans Creek to as far south as North River. North River discharge has similar response characteristics to the other four rivers measured, but with a lesser magnitude of discharge. Comparisons of monthly mean discharges from the Tamiami Canal flow control structures S-12-A, B, C, and D located on U.S. Highway 41 (Tamiami Trail) to the five station total monthly mean discharges indicate that the discharges from the five rivers are approximately 2 to 3 times the S-12-A, B, C, D discharges, and that the measured southwest coast discharge peaks lead the S-12-A, B, C, D discharge peaks by approximately 1 month. Residual total nitrogen and total phosphorus fluxes were estimated using linear regression models of discharge and flux. Monthly mean total nitrogen residual fluxes for the five southwest coast rivers ranged from approximately 0 to 390 short tons, whereas monthly mean total phosphorus residual fluxes ranged from approximately 0 to 6 short tons. Total nitrogen and total phosphorus residual fluxes at Lostmans Creek, and Broad, Harney, and Shark Rivers were similar in magnitude, each accounting for between 20 to 29 percent of the total measured residual flux. North River contributed between 3 to 4 percent of the total nitrogen and total phosphorus residual flux from the five rivers.

Florida↗
USGS2006

Characterization of surface-water resources in the Great Basin National Park area and their susceptibility to ground-water withdrawals in adjacent valleys, White Pine County, Nevada

Eight drainage basins and one spring within the Great Basin National Park area were monitored continually from October 2002 to September 2004 to quantify stream discharge and assess the natural variability in flow. Mean annual discharge for the stream drainages ranged from 0 cubic feet per second at Decathon Canyon to 9.08 cubic feet per second at Baker Creek. Seasonal variability in streamflow generally was uniform throughout the network. Minimum and maximum mean monthly discharges occurred in February and June, respectively, at all but one of the perennial streamflow sites. Synoptic-discharge, specific-conductance, and water- and air-temperature measurements were collected during the spring, summer, and autumn of 2003 along selected reaches of Strawberry, Shingle, Lehman, Baker, and Snake Creeks, and Big Wash to determine areas where surface-water resources would be susceptible to ground-water withdrawals in adjacent valleys. Comparison of streamflow and water-property data to the geology along each stream indicated areas where surface-water resources likely or potentially would be susceptible to ground-water withdrawals. These areas consist of reaches where streams (1) are in contact with permeable rocks or sediments, or (2) receive water from either spring discharge or ground-water inflow.

Scientific Investigations Report↗
USGS2006

Use of dye tracing to determine ground-water movement to Mammoth Crystal Springs, Sylvan Pass area, Yellowstone National Park, Wyoming

At the request of and in cooperation with the Geology Program at Yellowstone National Park, the U.S. Geological Survey conducted a hydrologic investigation of the Sylvan Pass area in June 2005 to determine the relation between surface water and ground-water flow to Mammoth Crystal Springs. Results of a dye-tracing investigation indicate that streamflow lost into talus deposits on Sylvan Pass enters the ground-water system and moves to the southeast to discharge at Mammoth Crystal Springs. Ground-water travel times to the springs from a distance of 1.45 miles and a vertical relief of 500 feet were less than 1 day, indicating apparent rates of movement of at least 8,000 feet per day, values that are similar to those in karst aquifers. Peak dye concentrations were reached about 2 days after dye injection, and transit time of most of the dye mass through the system was about 3 weeks. High permeability and rapid travel times within this aquifer also are indicated by the large variation in springflow in response to snowmelt runoff and precipitation, and by the high concentration of suspended sediment (turbidity) in the water discharging into the spring-fed lake.

Wyoming↗
USGS2007

Borehole geophysical monitoring of amendment emplacement and geochemical changes during vegetable oil biostimulation, Anoka County Riverfront Park, Fridley, Minnesota

The U.S. Geological Survey ( USGS ) conducted a series of geophysical investigations to monitor a field-scale biostimulation pilot project at the Anoka County Riverfront Park ( ACP ), downgradient from the Naval Industrial Reserve Ordnance Plant, in Fridley, Minnesota. The pilot project was undertaken by the U.S. Naval Facilities Engineering Command, Southern Division, for the purpose of evaluating biostimulation using emulsified vegetable oil to treat ground water contaminated with chlorinated hydrocarbons. Vegetable oil was introduced to the subsurface to serve as substrate for naturally occurring microbes, which ultimately break down chlorinated hydrocarbons into chloride, carbon dioxide, and water through oxidation-reduction reactions. In support of this effort, the USGS collected cross-borehole radar data and conventional borehole geophysical data in five site visits over 1.5 years to evaluate the effectiveness of geophysical methods for monitoring emplacement of the vegetable oil emulsion and for tracking changes in water chemistry. Radar zero-offset profile ( ZOP ) data, radar traveltime tomograms, electromagnetic ( EM ) induction logs, natural gamma logs, neutron porosity logs, and magnetic susceptibility logs were collected and analyzed. In order to facilitate data interpretation and to test the effectiveness of radar for monitoring oil-emulsion placement and movement, three injection mixtures with different radar signatures were used: (1) vegetable oil emulsion, (2) vegetable oil emulsion with a colloidal iron tracer, and (3) vegetable oil emulsion with a magnetite tracer. Based on petrophysical modeling, mixture (1) was expected to increase radar velocity and decrease radar attenuation relative to background—a water-saturated porous medium; mixtures (2) and (3) were expected to increase radar velocity and increase radar attenuation because of their greater electrical conductivity compared to background ground water. Radar ZOP data and tomograms show increased EM velocity in the vicinity of injection wells. Comparison of pre- and post-injection datasets shows that velocity anomalies are observed only in planes connected to injection wells, indicating that the emulsified vegetable oil does not migrate far after injection. In contrast to the localization of velocity anomalies, radar attenuation anomalies are observed in all zero-offset profiles, particularly those downgradient from the injection wells. Despite the expected signatures of different tracers, increases in attenuation are observed downgradient from all three injection wells; thus, we infer that the attenuation changes do not result from the iron tracers alone. Over the period of data collection, the slowness (reciprocal velocity) anomalies are relatively stable, whereas the attenuation anomalies generally increase in magnitude and extent. One explanation for the attenuation changes is that products of vegetable oil-enhanced biodegradation (for example, chloride) increase the specific conductance of ground water and thus bulk electrical conductivity and radar attenuation. This interpretation is supported by the results of EM-induction and magnetic susceptibility logs, which indicate increases in electrical conductivity in the absence of magnetic anomalies that might result from the iron and magnetite. Based on the geophysical data, conceptual models of the distributions of emulsified vegetable oil and ground water with altered chemistry were developed. The field data indicate that, in several cases, the plume of ground water with altered chemistry would not be detected by direct chemical sampling given the construction of monitoring wells; hence the geophysical data provide valuable site-specific insights for the interpretation of water samples and monitoring of biostimulation projects. Application of geophysical methods to data from the ACP demonstrated the utility of radar for monitoring biostimulation injections.

Minnesota↗
USGS2008

Development of a Monitoring Protocol to Detect Ecological Change in the Intertidal Zone of Sitka National Historical Park, Alaska

A pilot study to develop and test a probability-based intertidal monitoring protocol for Sitka National Historical Park was conducted from 1999 to 2003. In 1999, the basic design, with a focus on sampling the whole of the designated intertidal was created, and sampling was conducted for sessile species and large mobile invertebrates by point-intercept sampling of vertical transects and band surveys along transects, respectively. In 2002 and 2003, the same types of sampling were conducted, but quadrat sampling for small mobile invertebrates was added and then modified. This project has produced basic data on the presence, abundance, and spatial distribution of substrates and intertidal biota. Additionally, statistical power analyses conducted on the biological data have allowed assessment of the ability of the sampling to detect trends in the abundance of the predominant species. Current sampling has an 80 percent probability to detect +10 percent annual changes in abundance of all targeted species with an a = 0.05; the ability to detect -10 percent trends is not as uniformly high. Various options are discussed for decreasing the spatial variance of the data. The information presented provides a basis for discussion of the major questions being asked, how the sampling design might be reconfigured to be consistent in approach, and how the intertidal monitoring should interface with other potential intertidal monitoring.

Scientific Investigations Report↗
USGS2010

Proceedings of the U.S. Geological Survey Interdisciplinary Microbiology Workshop, Estes Park, Colorado, October 15-17, 2008

Preface A U.S. Geological Survey Interdisciplinary Microbiology Workshop was held in Estes Park, Colorado, on October 15-17, 2008. Participants came from all USGS regions and disciplines. This report contains abstracts from 36 presentations and 35 poster sessions and notes from 5 breakout sessions. The seven presentation topics follow: Ecology of wildlife and fish disease Mechanisms of fish and wildlife disease Microbial ecology Geographic patterns/visualization Public health and water quality Geomicrobiology Ecosystem function The six poster session topics follow: Wildlife disease Disease detection methods Water quality Microbial ecology Metabolic processes Tools and techniques Five working groups met in breakout sessions on October 16, 2008. The highlights for each working group are summarized in this report, and their goals are listed below: Working Group I: to plan a Fact Sheet on interdisciplinary microbiology in the USGS Working Group II: to plan a USGS interdisciplinary microbiology Web site Working Group III: to suggest ways to broadcast and publicize the types of microbiology conducted at the USGS Working Group IV: to identify emerging issues in USGS interdisciplinary microbiology research Working Group V: to identify potential opportunities for interdisciplinary microbiology work at the USGS After the workshop, the USGS interdisciplinary microbiology Web site was activated in June 2009 at http://microbiology.usgs.gov/.

Scientific Investigations Report↗
USGS2012

Sources and sinks of nitrogen and phosphorus to a deep, oligotrophic lake, Lake Crescent, Olympic National Park, Washington

Lake Crescent, in Olympic National Park in the northwest corner of Washington State is a deep-water lake renowned for its pristine water quality and oligotrophic nature. To examine the major sources and sinks of nutrients (as total nitrogen, total phosphorus, and dissolved nitrate), a study was conducted in the Lake Crescent watershed. The study involved measuring five major inflow streams, the Lyre River as the major outflow, recording weather and climatic data, coring lake bed sediment, and analyzing nutrient chemistry in several relevant media over 14 months. Water samples for total nitrogen, total phosphorous, and dissolved nitrate from the five inflow streams, the outlet Lyre River, and two stations in the lake were collected monthly from May 2006 through May 2007. Periodic samples of shallow water from temporary sampling wells were collected at numerous locations around the lake. Concentrations of nutrients detected in Lake Crescent and tributaries were then applied to the water budget estimates to arrive at monthly and annual loads from various environmental components within the watershed. Other sources, such as leaf litter, pollen, or automobile exhaust were estimated from annual values obtained from various literature sources. This information then was used to construct a nutrient budget for total nitrogen and total phosphorus. The nitrogen budget generally highlights vehicle traffic-diesel trucks in particular-along U.S. Highway 101 as a potential major anthropogenic source of nitrogen compounds in the lake. In contrast, contribution of nitrogen compounds from onsite septic systems appears to be relatively minor related to the other sources identified.

Washington↗
USGS2013

Evaluation of potential sources and transport mechanisms of fecal indicator bacteria to beach water, Murphy Park Beach, Door County, Wisconsin

Fecal Indicator Bacteria (FIB) concentrations in beach water have been used for many years as a criterion for closing beaches due to potential health concerns. Yet, current understanding of sources and transport mechanisms that drive FIB occurrence remains insufficient for accurate prediction of closures at many beaches. Murphy Park Beach, a relatively pristine beach on Green Bay in Door County, Wis., was selected for a study to evaluate FIB sources and transport mechanisms. Although the relatively pristine nature of the beach yielded no detection of pathogenic bacterial genes and relatively low FIB concentrations during the study period compared with other Great Lakes Beaches, its selection limited the number of confounding FIB sources and associated transport mechanisms. The primary sources of FIB appear to be internal to the beach rather than external sources such as rivers, storm sewer outfalls, and industrial discharges. Three potential FIB sources were identified: sand, swash-zone groundwater, and Cladophora mats. Modest correlations between FIB concentrations in these potential source reservoirs and FIB concentrations at the beach from the same day illustrate the importance of understanding transport mechanisms between FIB sources and the water column. One likely mechanism for transport and dispersion of FIB from sand and Cladophora sources appears to be agitation of Cladophora mats and erosion of beach sand due to storm activity, as inferred from storm indicators including turbidity, wave height, current speed, wind speed, sky visibility, 24-hour precipitation, and suspended particulate concentration. FIB concentrations in beach water had a statistically significant relation (p-value ‹0.05) with the magnitude of these storm indicators. In addition, transport of FIB in swash-zone groundwater into beach water appears to be driven by groundwater recharge associated with multiday precipitation and corresponding increased swash-zone groundwater discharge at the beach, as indicated by an increase in the specific conductance of beach water. Understanding the dynamics of FIB sources (sand, swash-zone groundwater, and Cladophora ) and transport mechanisms (dispersion and erosion from storm energy, and swash-zone groundwater discharge) is important for improving predictions of potential health risks from FIB in beach water.

Wisconsin↗
USGS2013

Relations between DNA- and RNA-based molecular methods for cyanobacteria and microcystin concentration at Maumee Bay State Park Lakeside Beach, Oregon, Ohio, 2012

Water samples were collected from Maumee Bay State Park Lakeside Beach, Oregon, Ohio, during the 2012 recreational season and analyzed for selected cyanobacteria gene sequences by DNA-based quantitative polymerase chain reaction (qPCR) and RNA-based quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results from the four DNA assays (for quantifying total cyanobacteria, total Microcystis , and Microcystis and Planktothrix strains that possess the microcystin synthetase E ( mcyE ) gene) and two RNA assays (for quantifying Microcystis and Planktothrix genera that are expressing the microcystin synthetase E ( mcyE ) gene) were compared to microcystin concentration results determined by an enzyme-linked immunosorbent assay (ELISA). Concentrations of the target in replicate analyses were log10 transformed. The average value of differences in log10 concentrations for the replicates that had at least one detection were found to range from 0.05 to >0.37 copy per 100 milliliters (copy/100 mL) for DNA-based methods and from >0.04 to >0.17 copy/100 mL for RNA-based methods. RNA has a shorter half-life than DNA; consequently, a 24-hour holding-time study was done to determine the effects of holding time on RNA concentrations. Holding-time comparisons for the RNA-based Microcystis toxin mcyE assay showed reductions in the number of copies per 100 milliliters over 24 hours. The log difference between time 2 hours and time 24 hours was >0.37 copy/100 mL, which was higher than the analytical variability (log difference of >0.17 copy/100 mL). Spearman’s correlation analysis indicated that microcystin toxin concentrations were moderately to highly related to DNA-based assay results for total cyanobacteria (rho=0.69), total Microcystis (rho=0.74), and Microcystis strains that possess the mcyE gene (rho=0.81). Microcystin toxin concentrations were strongly related with RNA-based assay results for Microcystis mcyE gene expression (rho=0.95). Correlation analysis could not be done for Planktothrix mcyE gene expression because of too few detections.

Ohio↗
USGS2014

Occurrence and origin of Escherichia coli in water and sediments at two public swimming beaches at Lake of the Ozarks State Park, Camden County, Missouri, 2011-13

In the past several years, the Missouri Department of Natural Resources has closed two popular public beaches, Grand Glaize Beach and Public Beach 1, at Lake of the Ozarks State Park in Osage Beach, Missouri when monitoring results exceeded the established Escherichia coli (E. coli) standard. As a result of the beach closures, the U.S. Geological Survey and Missouri University of Science and Technology, in cooperation with the Missouri Department of Natural Resources, led an investigation into the occurrence and origins of E. coli at Grand Glaize Beach and Public Beach 1. The study included the collection of more than 1,300 water, sediment, and fecal source samples between August 2011 and February 2013 from the two beaches and vicinity. Spatial and temporal patterns of E. coli concentrations in water and sediments combined with measurements of environmental variables, beach-use patterns, and Missouri Department of Natural Resources water-tracing results were used to identify possible sources of E. coli contamination at the two beaches and to corroborate microbial source tracking (MST) sampling efforts. Results from a 2011 reconnaissance sampling indicate that water samples from Grand Glaize Beach cove contained significantly larger E. coli concentrations than adjacent coves and were largest at sites at the upper end of Grand Glaize Beach cove, indicating a probable local source of E. coli contamination within the upper end of the cove. Results from an intensive sampling effort during 2012 indicated that E. coli concentrations in water samples at Grand Glaize Beach cove were significantly larger in ankle-deep water than waist-deep water, trended downward during the recreational season, significantly increased with an increase in the total number of bathers at the beach, and were largest during the middle of the day. Concentrations of E. coli in nearshore sediment (sediment near the shoreline) at Grand Glaize Beach were significantly larger in foreshore samples (samples collected above the shoreline) than in samples collected in ankle-deep water below the shoreline, significantly larger in the left and middle areas of the beach than the right area, and substantially larger than similar studies at E. coli- contaminated beaches on Lake Erie in Ohio. Concentrations of E. coli in the water column also were significantly larger after resuspension of sediments. Results of MST indicate a predominance of waterfowl-associated markers in nearshore sediments at Grand Glaize Beach consistent with frequent observations of goose and vulture fecal matter in sediment, especially on the left and middle areas of the beach. The combination of spatial and temporal sampling and MST indicate that an important source of E. coli contamination at Grand Glaize Beach during 2012 was E. coli released into the water column by bathers resuspending E. coli-contaminated sediments, especially during high-use days early in the recreational season.

Missouri↗
USGS2014

The relative importance of oceanic nutrient inputs for Bass Harbor Marsh Estuary at Acadia National Park, Maine

The U.S. Geological Survey and Acadia National Park (ANP) collaborated on a study of nutrient inputs into Bass Harbor Marsh Estuary on Mount Desert Island, Maine, to better understand ongoing eutrophication, oceanic nutrient inputs, and potential management solutions. This report includes the estimation of loads of nitrate, ammonia, total dissolved nitrogen, and total dissolved phosphorus to the estuary derived from runoff within the watershed and oceanic inputs during summers 2011 and 2012. Nutrient outputs from the estuary were also monitored, and nutrient inputs in direct precipitation to the estuary were calculated. Specific conductance, water temperature, and turbidity were monitored at the estuary outlet. This report presents a first-order analysis of the potential effects of projected sea-level rise on the inundated area and estuary volume. Historical aerial photographs were used to investigate the possibility of widening of the estuary channel over time. The scope of this report also includes analysis of sediment cores collected from the estuary and fringing marsh surfaces to assess the sediment mass accumulation rate. Median concentrations of nitrate, ammonium, and total dissolved phosphorus on the flood tide were approximately 25 percent higher than on the ebb tide during the 2011 and 2012 summer seasons. Higher concentrations on the flood tide suggest net assimilation of these nutrients in biota within the estuary. The dissolved organic nitrogen fraction dominated the dissolved nitrogen fraction in all tributaries. The median concentration of dissolved organic nitrogen was about twice as high on the on the ebb tide than the flood tide, indicating net export of dissolved organic nitrogen from the estuary. The weekly total oceanic inputs of nitrate, ammonium, and total dissolved phosphorus to the estuary were usually much larger than inputs from runoff or direct precipitation. The estuary was a net sink for nitrate and ammonium in most weeks during both years. Oceanic inputs of nitrate and ammonium were an important source of inorganic nitrogen to the estuary in both years. In both years, the total seasonal inputs of ammonium to the estuary in flood tides were much larger than the inputs from watershed runoff or direct precipitation. In 2011, the total seasonal input of nitrate from flood tides to the estuary was more than twice as large the inputs from watershed runoff and precipitation, but in 2012, the inputs from flood tides were only marginally larger than the inputs from watershed runoff and precipitation. Turbidity was measured intermittently in 2012, and the pattern that emerged from the measurements indicated that the estuary was a source of particulate matter to the ocean rather than the ocean being a source to the estuary. From the nutrient budgets determined for the estuary it is evident that oceanic sources of nitrate and ammonium are an important part of the supply of nutrients that are contributing to the growth of macroalgae in the estuary. The relative importance of these oceanic nutrients compared with sources within the watershed typically increases as the summer progresses and runoff decreases. It is likely that rising sea levels, estimated by the National Oceanic and Atmospheric Administration to be 11 centimeters from 1950 through 2006 in nearby Bar Harbor, have resulted in an increase in oceanic inputs (tidal volume and nutrients derived from oceanic sources).

Maine↗
USGS2014

Quantitative rock-fall hazard and risk assessment for Yosemite Valley, Yosemite National Park, California

Rock falls are common in Yosemite Valley, California, posing substantial hazard and risk to the approximately four million annual visitors to Yosemite National Park. Rock falls in Yosemite Valley over the past few decades have damaged structures and caused injuries within developed regions located on or adjacent to talus slopes highlighting the need for additional investigations into rock-fall hazard and risk. This assessment builds upon previous investigations of rock-fall hazard and risk in Yosemite Valley and focuses on hazard and risk to structures posed by relatively frequent fragmental-type rock falls as large as approximately 100,000 (cubic meters) in volume.

California↗
USGS2016

Monitoring plant tissue nitrogen isotopes to assess nearshore inputs of nitrogen to Lake Crescent, Olympic National Park, Washington

Mats of filamentous-periphytic algae present in some nearshore areas of Lake Crescent, Olympic National Park, Washington, may indicate early stages of eutrophication from nutrient enrichment of an otherwise highly oligotrophic lake. Natural abundance ratios of stable isotopes of nitrogen (δ 15 N) measured in plant tissue growing in nearshore areas of the lake indicate that the major source of nitrogen used by these primary producing plants is derived mainly from atmospherically fixed nitrogen in an undeveloped forested ecosystem. Exceptions to this pattern occurred in the Barnes Point area where elevated δ 15 N ratios indicate that effluent from septic systems also contribute nitrogen to filamentous-periphytic algae growing in the littoral zone of that area. Near the Lyre River outlet of Lake Crescent, the δ 15 N of filamentous-periphytic algae growing in close proximity to the spawning areas of a unique species of trout show little evidence of elevated δ 15 N indicating that nitrogen from on-site septic systems is not a substantial source of nitrogen for these plants. The δ 15 N data corroborate estimates that nitrogen input to Lake Crescent from septic sources is comparatively small relative to input from motor vehicle exhaust and vegetative sources in undeveloped forests, including litterfall, pollen, and symbiotic nitrogen fixation. The seasonal timing of blooms of filamentous-periphytic algal near the lake shoreline is also consistent with nitrogen exported from stands of red alder trees ( Alnus rubra ). Isotope biomonitoring of filamentous-periphytic algae may be an effective approach to monitoring the littoral zone for nutrient input to Lake Crescent from septic sources.

Washington↗
USGS2016

Flood-inundation maps for the Peckman River in the Townships of Verona, Cedar Grove, and Little Falls, and the Borough of Woodland Park, New Jersey, 2014

Digital flood-inundation maps for an approximate 7.5-mile reach of the Peckman River in New Jersey, which extends from Verona Lake Dam in the Township of Verona downstream through the Township of Cedar Grove and the Township of Little Falls to the confluence with the Passaic River in the Borough of Woodland Park, were created by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ depict estimates of the probable areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Peckman River at Ozone Avenue at Verona, New Jersey (station number 01389534). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ . Flood profiles were simulated for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated using the most current stage-discharge relations at USGS streamgages on the Peckman River at Ozone Avenue at Verona, New Jersey (station number 01389534) and the Peckman River at Little Falls, New Jersey (station number 01389550). The hydraulic model was then used to compute eight water-surface profiles for flood stages at 0.5-foot (ft) intervals ranging from 3.0 ft or near bankfull to 6.5 ft, which is approximately the highest recorded water level during the period of record (1979–2014) at USGS streamgage 01389534, Peckman River at Ozone Avenue at Verona, New Jersey. The simulated water-surface profiles were then combined with a geographic information system digital elevation model derived from light detection and ranging (lidar) data to delineate the area flooded at each water level. The availability of these maps along with Internet information regarding current stage from the USGS streamgage provides emergency management personnel and residents with information, such as estimates of inundation extents, based on water stage, that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

New Jersey↗
USGS2018

Collection methods and quality assessment for Escherichia coli, water quality, and microbial source tracking data within Tumacácori National Historical Park and the upper Santa Cruz River, Arizona, 2015-16

Tumacácori National Historical Park protects the culturally important Mission, San José de Tumacácori, while also managing a portion of the ecologically diverse riparian corridor of the Santa Cruz River. This report describes the methods and quality assurance procedures used in the collection of water samples for the analysis of Escherichia coli ( E. coli ), microbial source tracking markers, suspended sediment, water-quality parameters, turbidity, and the data collection for discharge and stage; the process for data review and approval is also described. Finally, this report provides a quantitative assessment of the quality of the E. coli , microbial source tracking, and suspended sediment data. The data-quality assessment revealed that bias attributed to field and laboratory contamination was minimal, with E. coli detections in only 3 out of 33 field blank samples analyzed. Concentrations in the field blanks were several orders of magnitude lower than environmental concentrations. The microbial source tracking (MST) field blank was below the detection limit for all MST markers analyzed. Laboratory blanks for E. coli at the USGS Arizona Water Science Center and laboratory blanks for MST markers at the USGS Ohio Water Microbiology Laboratory were all below the detection limit. Irreplicate data for E. coli and suspended sediment indicated that bias was not introduced to the data by combining samples collected using discrete sampling methods with samples collected using automatic sampling methods. The split and sequential E. coli replicate data showed consistent analytical variability and a single equation was developed to explain the variability of E. coli concentrations. An additional analysis of analytical variability for E. coli indicated analytical variability around 18 percent relative standard deviation and no trend was observed in the concentration during the processing and analysis of multiple split-replicates. Two replicate samples were collected for MST and individual markers were compared for a base flow and flood sample. For the markers found in common between the two types of samples, the relative standard deviation for the base flow sample was more than 3 times greater than the markers in the flood sample. Sequential suspended sediment replicates had a relative standard deviation of about 1.3 percent, indicating that environmental and analytical variability was minimal. A holding time review and laboratory study analysis supported the extended holding times required for this investigation. Most concentrations for flood and base-flow samples were within the theoretical variability specified in the most probable number approach suggesting that extended hold times did not overly influence the final concentrations reported.

Arizona↗
USGS2018

Assessment of geochemical and hydrologic conditions near Old Yuma Mine in Saguaro National Park, Arizona, 2014–17

The Old Yuma Mine is an abandoned copper, lead, zinc, silver, and gold mine located within the boundaries of Saguaro National Park, Tucson Mountain District, Arizona. This study analyzed the geochemistry of sediments associated with the Old Yuma Mine and assessed hydrologic and geochemical conditions of groundwater to evaluate the area surrounding the Old Yuma Mine. The purpose of the study was to establish the geochemical signature of material associated with the Old Yuma Mine and to compare it with background material and groundwater in the area. Few groundwater samples exceeded the U.S. Environmental Protection Agency (EPA) drinking water standards. Concentrations of several elements were elevated in the waste rock and mine tailings compared with concentrations in sediments collected in background areas. A subset of 15 sediment samples was leached to simulate precipitation interacting with the solid material. Analysis of leachate samples compared to groundwater samples suggests that groundwater samples collected in this study are distinct from leachate samples associated with mining related material. Results suggest that at this time groundwater samples collected during this investigation are not influenced by elements leached from Old Yuma Mine materials.

Arizona↗
USGS2018

Vibration monitoring results near a bat hibernaculum at Mammoth Cave National Park, Kentucky, March 2016

Vibrations originating from construction of a new walkway in a passage of Mammoth Cave, from walking personnel simulating a bat survey, and from ambient sources were measured near a bat hibernaculum beneath Mammoth Cave National Park, Kentucky, to determine if the vibrations were disturbing the hibernating bats. Data presented indicate direction and magnitude of the vibrations. The seven sources of vibration that were recorded include hammer drill (one location), plate compactor (two locations), jackhammer (two locations), personnel simulating a bat survey near the hibernaculum (walking throughout the cave), and background levels. Vibrations were measured for approximately 10 seconds during each triggering of the source and each source was recorded 5–10 times to represent the reproducibility of the vibrations. The plate compactor produced the largest velocity of 0.00226 inch per second on one of the longitudinal components. The simulated bat survey produced the largest value of acceleration of 0.34 inch per square second in the vertical component. Maximum vertical velocities and accelerations did not exceed literature values for human perception or visible agitation in laboratory mice.

Kentucky↗