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USGS2008

Integrated impact of tropical cyclones on sea surface chlorophyll in the North Atlantic

Past studies have shown that surface chlorophyll-a concentrations increase in the wake of hurricanes. Given the reported increase in the intensity of North Atlantic hurricanes in recent years, increasing chlorophyll-a concentrations, perhaps an indication of increasing biological productivity, would be an expected consequence. However, in order to understand the impact of variable hurricane activity on ocean biology, the magnitude of the hurricane-induced chlorophyll increase relative to other events that stir or mix the upper ocean must be assessed. This study investigates the upper ocean biological response to tropical cyclones in the North Atlantic from 1997-2005. Specifically, we quantitatively compare the anomalous chlorophyll-a concentrations created by cyclone activity to the total distribution of anomalies in the subtropical waters. We show that the cyclone-induced chlorophyll-a increase has minimal impact on the integrated biomass budget, a result that holds even when taking into consideration the lagged and asymmetrical response of ocean color. Copyright 2008 by the American Geophysical Union.

Geophysical Research Letters↗

USGS1982

Use of ozone in a water reuse system for salmonids

A water reuse system is described in which ozone is used in addition to biological filters to remove toxic metabolic wastes from the water. The system functions at a higher rate of efficiency than has been reported for other reuse systems and supports excellent growth of rainbow trout (Salmo gairdneri).

Progressive Fish-Culturist↗

USGS2013

Water temperatures in select nearshore environments of the Colorado River in Grand Canyon, Arizona, during the Low Steady Summer Flow experiment of 2000

Water releases from Glen Canyon Dam, Arizona, are the primary determinant of streamflow, sediment transport, water quality, and aquatic and riparian habitat availability in the Colorado River downstream of the dam in Grand Canyon. The presence and operation of the dam have transformed the seasonally warm Colorado River into a consistently cold river because of hypolimnetic, or deep-water, releases from the penstock withdrawal structures on the dam. These releases have substantially altered the thermal regime of the downstream riverine environment. This, in turn, has affected the biota of the river corridor, particularly native and nonnative fish communities and the aquatic food web. In the spring and summer of 2000, a Low Steady Summer Flow experiment was conducted by the U.S. Geological Survey and the Bureau of Reclamation to evaluate the effects of the experimental flow on physical and biological resources of the Colorado River ecosystem downstream from Glen Canyon Dam to Lake Mead on the Arizona-Nevada border. This report describes the water temperatures collected during the experimental flow from 14 nearshore sites in the river corridor in Grand Canyon to assess the effects of steady releases on the thermal dynamics of nearshore environments. These nearshore areas are characterized by low-velocity flows with some degree of isolation from the higher velocity flows in the main channel and are hypothesized to be important rearing environments for young native fish. Water-temperature measurements were made at 14 sites, ranging from backwater to open-channel environments. Warming during daylight hours, relative to main-channel temperatures, was measured at all sites in relation to the amount of isolation from the main-channel current. Boat traffic, amount of direct solar radiation, and degree of isolation from the main-channel current appear to be the primary factors affecting the differential warming of the nearshore environment.

Arizona↗

USGS1981

Hydrology of area 4, Eastern Coal Province, Pennsylvania, Ohio, and West Virginia

Area 4 (one of the 24 hydrologic areas defining the Eastern Coal Province) is located at the northern end of the Eastern Coal Province in eastern Ohio, northern West Virginia, and western Pennsylvania. It is part of the upper Ohio River basin, which includes the Beaver, Mahoning, and Shenango Rivers. The area is underlain by rocks of the Pottsville, Allegheny, Conemaugh, Monongahela Groups (or Formations) and Dunkard Group. Area 4 has a temperate climate with an annual average rainfall of 38 to 42 inches, most of its area is covered by forest. The soils have a high erosion potential where the vegetation cover is removed. In response to Public Law 95-87, 132 sites were added to the existing surface-water data-collection network in area 4. At these added sites, collected data includes discharge, water quality, sediment, and biology. The data are available from computer storage through the National Water Data Exchange (NAWDEX) or the published annual Water Resources Data reports for Ohio, Pennsylvania, and West Virginia. Hydrologic problems related to mining are: (1) Erosion and increased sedimentation, and (2) degradation of water quality. Erosion and sedimentation are associated chiefly with surface mining. Sediment yields increase drastically when vegetation is removed from the highly erosive soils. Degradation of water quality can be caused by acid-mine drainage from underground and surface mining. More than half the acid-mine drainage effluent in area 4 comes from underground mines. The rest seeps from abandoned surface mines. Usually in reclaimed surface mines the overburden is replaced in such a short time after the coal is taken out that oxidation of acid-forming minerals, commonly pyrite or marcasite, is not complete or is neutralized by the buffering action of calcareous minerals in the soils. (USGS)

Open-File Report↗

USGS2014

Effects of land use, stream habitat, and water quality on biological communities of wadeable streams in the Illinois River Basin of Arkansas, 2011 and 2012

The Illinois River Basin includes an area of diverse land use in northwestern Arkansas. Land-use data collected in 2006 indicate that most of the land in the basin is agricultural. The agricultural land is used primarily for production of poultry and cattle. Eighteen sites were selected from the list of candidate sites based on drainage area, land use, presence or absence of an upstream wastewater-treatment plant, water quality, and other information gathered during the reconnaissance. An important consideration in the process was to select sites along gradients of forest to urban land use and forest to agricultural land use. Water-quality samples were collected for analysis of nutrients, and a multiparameter field meter was used to measure water temperature, specific conductance, pH, and dissolved oxygen. Streamflow was measured immediately following the water-quality sampling. Macroalgae coverage was estimated and periphyton, macroinvertebrate, and fish communities were sampled at each site. Stream habitat also was assessed. Many types of land-use, water-quality, and habitat factors affected one or more aspects of the biological communities. Several macroinvertebrate and fish metrics changed in response to changes in percent forest; sites that would be considered most disturbed, based on these metrics, are sites with the highest percentages of urban land use in their associated basins. The presence of large mats of macroalgae was one of the most noticeable biological characteristics in several streams within the Illinois River Basin. The highest macroalgae percent cover values were recorded at four sites downstream from wastewater-treatment plants. Macroalgae percent cover was strongly correlated only with bed substrate size, canopy closure, and specific conductance. Periphyton metrics were most often and most strongly correlated with riparian shading, specific conductance, substrate turbidity, percent agriculture, poultry house density, and unpaved road density; some of these factors were strongly correlated with percent forest, percent urban, or percent agriculture. Total biovolume of periphyton was not strongly correlated with any of the land use, habitat, or water-quality factors assessed in the present study. Although algal growth typically increases with higher nutrient concentrations and less shading, the standing crop of periphyton on rocks can be reduced by herbivorous macroinvertebrates and fish, which may explain why total biovolume in Ozark streams was not strongly affected by water-quality (or other habitat) factors. A macroinvertebrate index and several macroinvertebrate metrics were adversely affected by increasing urban and agricultural land use and associated environmental factors. Factors most commonly affecting the index and metrics included factors associated with water quality, stream geometry, sediment, land-use percentages, and road density. In general, the macroinvertebrate index was higher (indicative of least disturbance) at sites with greater percentages of forest in their basins, lower percentages of urban land in their basins, and lower paved road density. Upstream wastewater-treatment plants affected several metrics. For example, three of the five lowest macroinvertebrate index scores, two of the five lowest percent predator values, and two of the five highest percent gatherer-collector values were at sites downstream from wastewater-treatment plants. The Ozark Highlands fish index of biotic integrity and several fish metrics were adversely affected by increasing urban and agricultural land use and associated factors. Factors affecting these metrics included factors associated with nutrients, sediment, and shading. In general, the fish index of biotic integrity was higher at sites with higher percentages of forest in their basins, lower percentages of urban land in their basins, higher unpaved road density, and lower paved and total road density. Upstream wastewater-treatment plants seemed to affect some fish community metrics substantially but had little effect on other metrics. For example, three of the five lowest relative abundances of lithophilic spawner minus stonerollers and four of the five highest stoneroller abundances were at sites downstream from wastewater-treatment plants. Interpretations of the results of the study described in this report are limited by a number of factors. These factors individually and collectively add to uncertainty and variability in the responses to various environmental stresses. Notwithstanding the limiting factors, the biological responses of macroalgae cover and periphyton, macroinvertebrate, and fish metrics to environmental variables provide multiple lines of evidence that biological communities of these streams are affected by recent and ongoing land-use practices. For several biological metrics there appears to be a threshold of about 40 to 50 percent forest where values of these metrics change in magnitude. However, the four sites with more than 50 percent forest in their basins were the four sites sampled in late May–early June of 2012 (rather than July–August of 2011). The relative influence of season and forest percentage on the biological communities at these sites is unknown.

Arkansas↗

USGS2015

Global patterns and environmental controls of perchlorate and nitrate co-occurrence in arid and semi-arid environments

Natural perchlorate (ClO 4 − ) is of increasing interest due to its wide-spread occurrence on Earth and Mars, yet little information exists on the relative abundance of ClO 4 − compared to other major anions, its stability, or long-term variations in production that may impact the observed distributions. Our objectives were to evaluate the occurrence and fate of ClO 4 − in groundwater and soils/caliche in arid and semi-arid environments (southwestern United States, southern Africa, United Arab Emirates, China, Antarctica, and Chile) and the relationship of ClO 4 − to the more well-studied atmospherically deposited anions NO 3 − and Cl − as a means to understand the prevalent processes that affect the accumulation of these species over various time scales. ClO 4 − is globally distributed in soil and groundwater in arid and semi-arid regions on Earth at concentrations ranging from 10 −1 to 10 6 μg/kg. Generally, the ClO 4 − concentration in these regions increases with aridity index, but also depends on the duration of arid conditions. In many arid and semi-arid areas, NO 3 − and ClO 4 − co-occur at molar ratios (NO 3 − /ClO 4 − ) that vary between ∼10 4 and 10 5 . We hypothesize that atmospheric deposition ratios are largely preserved in hyper-arid areas that support little or no biological activity (e.g. plants or bacteria), but can be altered in areas with more active biological processes including N 2 fixation, N mineralization, nitrification, denitrification, and microbial ClO 4 − reduction, as indicated in part by NO 3 − isotope data. In contrast, much larger ranges of Cl − /ClO 4 − and Cl − /NO 3 − ratios indicate Cl − varies independently from both ClO 4 − and NO 3 − . The general lack of correlation between Cl − and ClO 4 − or NO 3 − implies that Cl − is not a good indicator of co-deposition and should be used with care when interpreting oxyanion cycling in arid systems. The Atacama Desert appears to be unique compared to all other terrestrial locations having a NO 3 − /ClO 4 − molar ratio ∼10 3 . The relative enrichment in ClO 4 − compared to Cl − or NO 3 − and unique isotopic composition of Atacama ClO 4 − may reflect either additional in-situ production mechanism(s) or higher relative atmospheric production rates in that specific region or in the geological past. Elevated concentrations of ClO 4 − reported on the surface of Mars, and its enrichment with respect to Cl − and NO 3 − , could reveal important clues regarding the climatic, hydrologic, and potentially biologic evolution of that planet. Given the highly conserved ratio of NO 3 − /ClO 4 − in non-biologically active areas on Earth, it may be possible to use alterations of this ratio as a biomarker on Mars and for interpreting major anion cycles and processes on both Mars and Earth, particularly with respect to the less-conserved NO 3 − pool terrestrially.

Geochimica et Cosmochimica Acta↗

USGS2026

Working group on American Eel (WGAMEEL; outputs from 2024 meeting)

The Working Group on American Eel (WGAMEEL) met virtually three times in 2022-2024 to address the five Terms of Reference (ToRs) of its three-year term. The first two ToRs tasked WGAMEEL with listing and evaluating data on American eel landings, abundance indices, and spatial and habitat data and also to describe assessment methods used in Canada and the US. Canada-wide American eel trajectory was estimated using 12 fishery-independent datasets. Generally, longer datasets had more negative trends than shorter ones. Limiting data to the post-2000 years produced fewer negative trends that did not differ from zero, suggesting the observed declines occurred pre-2000. Spatial modelling for American eel requires knowledge and mapping that covers the breadth of habitat types occupied by the species, including freshwater, estuarine, and marine environments. In recent years there has been an expansion of online databases with data from the aquatic environment, particularly in freshwater, with estuarine and marine data less consistently documented. This report broadly compiles abiotic data series of relevance to American eel. A larger challenge for spatial modelling will be acquiring enough high quality, georeferenced biological data sets with suitable observations to assess occurrence, abundance, and trends over time in a spatial framework. The third ToR considered Indigenous Knowledge Systems for American eel. A survey reaching First Nations representatives from four Canadian provinces confirmed the cultural importance of eels in Indigenous communities, and that Indigenous knowledge possessed by the participant groups are place-based and contextual, especially regarding threats impacting eels. The final two ToRs focused on identifying stock assessment modelling approaches applicable to American and European eel, and assessing whether any of these approaches might be appropriate for American eel management moving forward. WGAMEEL evaluated the various approaches for assessing American eel or providing management advice. Two approaches that could be completed in the next few years because of their minimal data needs are index-based methods and catch-only method. A suite of approaches considered by WGAMEEL that would take more time and data were spatial or habitat models, management strategy evaluation, and spawner-per-recruit (SPR) models potentially paired with meta-population models.

ICES Scientific Reports↗

USGS1997

World Wide Web home page for the South Platte NAWQA

A World Wide Web home page for the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program, South Platte River Basin study is now online. The home page includes information about the basinwide investigation and provides viewing and downloading access to physical, chemical, and biological data collected by the study team.

Colorado↗

USGS2002

Evaluation of airborne image data and LIDAR main stem data for monitoring physical resources within the Colorado River ecosystem

This study evaluated near-infrared LIDAR data acquired over the main-stem channel at four long-term monitoring sites within the Colorado River ecosystem (CRE) to determine the ability of these data to provide reliable indications in changes in water elevation over time. Our results indicate that there is a good correlation between the LIDAR water-surface elevations and ground measurements of water-edge elevation, but there are also inherent errors in the LIDAR data. The elevation errors amount to about 50 cm and therefore temporal changes in water-surface elevation that exceed this value by the majority of data at a particular location can be deemed significant or real. This study also evaluated airborne image data for producing photogrammetric elevation data and for automated mapping of sand bars and debris flows within the CRE. The photogrammetric analyses show that spatial resolutions of ≤ 10 cm are required to produce vertical accuracies < 20 cm and that digitally acquired data cannot yet support this monitoring requirement. The mapping analyses indicate that CIR image data are far superior to true-color and panchromatic image data in mapping sand bars and debris flows. The analyses also show that the CIR color information provide almost as much mapping capability as do the combination of CIR color and CIR image texture. Therefore, CIR image data should always be given preference in image data collections, not only for the physical resource program, but also for the biologic resource program.

Arizona↗

USGS2007

Science Review for the Scott Bar Salamander (Plethodon asupak) and the Siskiyou Mountains Salamander (P. stormi): Biology, Taxonomy, Habitat, and Detection Probabilities/Occupancy

The Plethodon elongatus Complex in the Klamath-Siskiyou Ecoregion of southern Oregon and northern California includes three species: the Del Norte salamander, Plethodon elongatus; the Siskiyou Mountains salamander, P. stormi; and the Scott Bar salamander, P. asupak. This review aims to summarize the current literature and information available on select topics for P. stormi and P. asupak. These are both terrestrial salamanders belonging to the Family Plethodontidae, which contains more species and has a wider geographic distribution than any other family of salamanders (Wake 1966, 2006; Pough 1989). The genera of this family have greatly diversified ecologically across North America, Central America, northern South America, Sardinia, southeastern France and northwestern Italy, and have recently been discovered on the Korean peninsula (Min et al. 2005). The genus Plethodon is found exclusively in North America and is split into three distinct clades, based upon morphology and phylogenetics (Highton and Larson 1979): eastern small Plethodon, eastern large Plethodon, and the western Plethodon. The western Plethodon are the greatest representation of Plethodontidae in the Pacific Northwest, with 8 species. The two species with the most restricted ranges of these regional congeners are the Siskiyou Mountains and Scott Bar salamanders. These salamanders occupy the interior of the Klamath-Siskiyou Ecoregion which straddles the California and Oregon state lines, between Siskiyou County (CA) and Jackson and Josephine Counties (OR). The relatively recent discovery of P. asupak (Mead et al. 2005) and the limited range of both species have created an environment of uncertain conservation status for these species. This review will focus on four central topics of concern for land and resource managers: Biology; Taxonomy; Habitat; and Detection Probabilities/Occupancy.

Open-File Report↗

USGS2009

NBII-SAIN Data Management Toolkit

The Strategic Plan for the U.S. Geological Survey Biological Informatics Program (2005-2009) recognizes the need for effective data management: Though the Federal government invests more than $600 million per year in biological data collection, it is difficult to address these issues because of limited accessibility and lack of standards for data and information...variable quality, sources, methods, and formats (for example observations in the field, museum specimens, and satellite images) present additional challenges. This is further complicated by the fast-moving target of emerging and changing technologies such as GPS and GIS. Even though these technologies offer new solutions, they also create new informatics challenges (Ruggiero and others, 2005). The USGS National Biological Information Infrastructure program, hereafter referred to as NBII, is charged with the mission to improve the way data and information are gathered, documented, stored, and accessed. The central objective of this project is a direct reflection of the purpose of NBII as described by John Mosesso, Program Manager of the U.S. Geological Survey-Biological Informatics Program-GAP Analysis: At the outset, the reason for bringing about NBII was that there were significant amounts of data and information scattered all over the U.S., not accessible, in incompatible formats, and that NBII was tasked with addressing this problem...NBII's focus is to pull data together that truly matters to someone or communities. Essentially, the core questions are: 1) what are the issues, 2) where is the data, and 3) how can we make it usable and accessible (John Mosesso, U.S. Geological Survey, oral commun., 2006). Redundancy in data collection can be a major issue when multiple stakeholders are involved with a common effort. In 2001 the U.S. General Accounting Office (USGAO) estimated that about 50 percent of the Federal government's geospatial data at the time was redundant. In addition, approximately 80 percent of the cost of a spatial information system is associated with spatial data collection and management (U.S. General Accounting Office, 2003). These figures indicate that the resources (time, personnel, money) of many agencies and organizations could be used more efficiently and effectively. Dedicated and conscientious data management coordination and documentation is critical for reducing such redundancy. Substantial cost savings and increased efficiency are direct results of a pro-active data management approach. In addition, details of projects as well as data and information are frequently lost as a result of real-world occurrences such as the passing of time, job turnover, and equipment changes and failure. A standardized, well documented database allows resource managers to identify issues, analyze options, and ultimately make better decisions in the context of adaptive management (National Land and Water Resources Audit and the Australia New Zealand Land Information Council on behalf of the Australian National Government, 2003). Many environmentally focused, scientific, or natural resource management organizations collect and create both spatial and non-spatial data in some form. Data management appropriate for those data will be contingent upon the project goal(s) and objectives and thus will vary on a case-by-case basis. This project and the resulting Data Management Toolkit, hereafter referred to as the Toolkit, is therefore not intended to be comprehensive in terms of addressing all of the data management needs of all projects that contain biological, geospatial, and other types of data. The Toolkit emphasizes the idea of connecting a project's data and the related management needs to the defined project goals and objectives from the outset. In that context, the Toolkit presents and describes the fundamental components of sound data and information management that are common to projects involving biological, geospatial, and other related data

Open-File Report↗

USGS2015

Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS 2 ) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

Tennessee↗

USGS2010

Puget Sound shorelines and the impacts of armoring: Proceedings of a state of the science workshop, May 2009

The widespread extent and continued construction of seawalls and bulkheads on Puget Sound's beaches has emerged as a significant issue in shoreline management and coastal restoration in the region. Concerns about the impacts of shoreline armoring and managing the potential risks to coastal property are in many ways similar to those in other places, but Puget Sound also poses unique challenges related to its sheltered setting, glacially formed geology, rich estuarine ecology, and historical development pattern. The effects of armoring on shorelines are complex, involving both physical and biological science and requiring consideration of the cumulative impacts of small-scale activities over large scales of space and time. In addition, the issue is controversial, as it often places strongly held private interests in protecting shoreline property against broad public mandates to preserve shorelines for public uses and to protect environmental resources. Communities making difficult decisions about regulating shoreline activities and prioritizing restoration projects need to be informed by the best science available. To address these issues, a scientific workshop was convened in May 2009, specifically to bring local and national experts together to review the state of the science regarding the physical and biological impacts of armoring on sheltered shorelines such as those of Puget Sound.

Washington↗

USGS1978

The biology of Salt Wells Creek and its tributaries, southwestern Wyoming

A description of aquatic organisms and biological communities is presented for Salt Wells Creek, a plains stream in the Green River basin. The description includes seasonal population fluctuations of benthic organisms and algae, the food pyramid, and nutrient relations between various types of plants and animals. The algae and stream invertebrates were studied to determine baseline data and biological indicators of water quality. (Woodard-USGS).

Water-Resources Investigations Report↗

USGS2019

Spatial and temporal variability of fish assemblages in acidified streams: Implications for long-term monitoring

Numerous studies have established strong linkages between acid deposition, soil and surface-water acidification, and toxicity to aquatic biota. Little is known however, about the effects of acidification on fish assemblages in headwater streams because they are highly variable, and pre-acidification data are often lacking. The primary purpose of this study was to describe spatial and interannual (temporal) variability of fish assemblages in headwater streams affected by acidification so that future recovery targets and monitoring strategies can be established. Fish communities and water chemistry were sampled at 48 headwater streams in the Western Adirondack Mountains of New York during the summers of 2014 to 2016 to characterize the present-day condition of water quality and local fish assemblages. Additionally, data from six Adirondack streams that were sampled annually from 2014-16 were combined with data from seven streams in the Catskill Mountain region sampled annually for three or more years for an analysis of temporal variability. Inorganic monomeric aluminum concentrations (Ali, the toxic form of Al) were less than 1.0 µmol L-1, between 1 and 2 µmol L-1, and greater than 2 µmol L-1 in 79%, 13%, and 8% of the 48 Adirondack streams. Richness, abundance, and biomass of fish assemblages were negatively related to Ali concentrations. In streams with Ali concentrations less than 1.0 µmol L-1, species richness, density, and biomass averaged 2.0 species, 444.2 fish/0.1 ha, and 1924.4 g/0.1 ha, respectively, and the density and biomass of Brook Trout populations averaged 280.8 fish/0.1 ha and 1384.0 g/0.1 ha. These values may provide a reasonable approximation of fish community condition prior to anthropogenic acidification and can be used as targets for assessing future recovery of acidified streams. A power analysis that considered 21 fish metrics indicated a strong negative relationship between interannual metric variability and statistical power for detecting change over time. Large differences were identified in the sample size necessary to achieve adequate power (0.8) depending on the metric utilized. In general, greater statistical power was obtained from metrics based on entire fish communities and from metrics standardized by reach length or sampling effort. Given the variability observed in our dataset, most metrics could detect a change of 30% with moderate effort, suggesting this may be an appropriate goal for future monitoring. Together, knowledge of biological recovery targets and the statistical power obtained from various fish metrics can be used to develop the most effective strategies for monitoring and assessing biological recovery in New York streams.

New York↗

USGS1984

Habitat Suitability Index Models: Lake trout (exclusive of the Great Lakes)

The lake trout is an important commercial and sport fish in North America. In the Central Rocky Mountain regi on, 1ake trout are common ly referred to as "mackinaw". There is good evidence that lake trout should be called "1 ake charr" (Morton 1980). No subspecies of lake trout is presently recognized (Robins et al. 1980). The species, however, has extreme variability throughout its range, making it difficult to draw general conclusions about its biology (Martin and Olver 1980).

FWS/OBS↗

USGS2015

Biological data for water in Lake Powell and from Glen Canyon Dam releases, Utah and Arizona, 1990–2009

Biological samples from various locations on Lake Powell and in the Colorado River in the tail water downstream of Glen Canyon Dam were collected by the Bureau of Reclamation and U.S. Geological Survey from December 1990 through December 2009 as part of a long-term water-quality monitoring program that began in 1964. These samples consisted of discrete (1-m deep) chlorophyll samples, discrete (1-m deep) wholewater phytoplankton samples, and 30-m vertically composited zooplankton samples filtered through an 80-µm plankton net. Chlorophyll concentration was determined by acetone extraction followed by trichromatic spectroscopy on 2,051 samples. Phytoplankton analysis consisted of identification to the genus or species level, enumeration, and estimation of biovolume on 1,397 samples. Phytoplankton analysis identified 646 different phytoplankton taxa. Zooplankton analysis consisted of identification to the genus or species level, enumeration, and estimation of biomass from 1,898 samples. Zooplankton analysis identified 114 different zooplankton taxa. The results of these analyses are presented in this report. From this record, further interpretation may be made concerning primary and secondary production in Lake Powell. These data provide a linkage between physical and chemical water-quality data and fisheries investigations in Lake Powell. They also provide information regarding the export of biological material from Glen Canyon Dam.

Utah, Arizona↗

USGS2016

Aquatic biological communities and associated habitats at selected sites in the Big Wood River Watershed, south-central Idaho, 2014

Assessments of streamflow (discharge) parameters, water quality, physical habitat, and biological communities were completed between May and September 2014 as part of a monitoring program in the Big Wood River watershed of south-central Idaho. The sampling was conducted by the U.S. Geological Survey in cooperation with Blaine County, Trout Unlimited, the Nature Conservancy, and the Wood River Land Trust to help identify the status of aquatic resources at selected locations in the watershed. Information in this report provides a basis with which to evaluate and monitor the long-term health of the Big Wood River and its major tributaries. Sampling sites were co-located with existing U.S. Geological Survey streamgaging stations: three on the main stem Big Wood River and four on the North Fork Big Wood River (North Fork), Warm Springs Creek (Warm Sp), Trail Creek (Trail Ck), and East Fork Big Wood River (East Fork) tributaries. The analytical results and quality-assurance information for water quality, physical habitat, and biological community samples collected at study sites during 2 weeks in September 2014 are summarized. Water-quality data include concentrations of major nutrients, suspended sediment, dissolved oxygen, and fecal-coliform bacteria. To assess the potential effects of nutrient enrichment on algal growth, concentrations of periphyton biomass (chlorophyll- a and ash free dry weight) in riffle habitats were determined at each site. Physical habitat parameters include stream channel morphology, habitat volume, instream structure, substrate composition, and riparian vegetative cover. Biological data include taxa richness, abundance, and stream-health indicator metrics for macroinvertebrate and fish communities. Statistical summaries of the water-quality, habitat, and biological data are provided along with discussion of how these findings relate to the health of aquatic resources in the Big Wood River watershed. Seasonal discharge patterns using statistical summaries of daily discharge from selected sites are reported for water years 2012–15. Results showed that annual average daily mean discharge increased from the Big Wood River near Ketchum, ID (BW Ketchum) downstream to the Big Wood River at Hailey, ID (BW Hailey), but decreased by nearly 50 percent from BW Hailey downstream to Big Wood River at Stanton Crossing near Bellevue, ID (BW Stanton). Annual variability in daily mean discharge among main-stem sites was highest at BW Stanton, suggesting that this part of the river may be subject to some level of flow alteration. Hydrologic alterations resulting in flow reduction can contribute to higher water temperature, especially during the summer months when conditions are often most stressful to fish and other stream organisms. Daily water temperature and water temperature trends from June to September 2014 are reported for select tributary and main-stem sites on the Big Wood River and can be used to assess the potential for biological impairment based on aquatic life temperature criteria for cold-water streams. The State of Idaho maximum temperature criteria for protection of cold-water aquatic life of 22 °C was exceeded at Warm Sp and BW Stanton during summer 2014, but at none of the other main-stem or tributary sites. The 13 °C critical temperature criterion for salmonid spawning was exceeded in early July 2014 at BW Ketchum and BW Hailey near the end of the rainbow trout critical spawning and rearing period. Temperature exceedances were most frequent at BW Stanton, where exceedances for rainbow trout and brown trout occurred from May through early July 2014 during most of the critical spawning and rearing period. Water quality and habitat availability did not seem to be limiting for fish or other aquatic organisms at most sites in the Big Wood River watershed. Water quality assessments in September 2014 determined no exceedances of total maximum daily load target levels. The availability and quality of habitat was limited at BW Stanton, where shallow-water habitat conditions prevailed. Macroinvertebrate community diversity was high at all sites except for BW Stanton, where low community diversity was attributed to low species richness and high abundances of a few tolerant taxa. Presence of low species diversity and high macroinvertebrate tolerance values at BW Stanton indicates that benthic community condition and stream health were reduced at that location. Fish surveys done in September 2014 did not indicate any significant reductions in native fish communities in the Big Wood River or its tributaries. Native rainbow trout ( Oncorhynchus mykiss ) and Wood River sculpin ( Cottus leiopomus ) were the dominant fish species in the drainage and were found at all tributary and main-stem sites. Non-native brown ( Salmo trutta ) and brook trout ( Salvelinus fontinalis ) were limited to lower drainage sites on the Big Wood River (BW Hailey and BW Stanton), and occurred in relatively low numbers.

Idaho↗