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Forecasting selenium discharges to the San Francisco Bay-Delta Estuary: Ecological effects of a proposed San Luis drain extension

During the next few years, federal and state agencies may be required to evaluate proposals and discharge permits that could significantly change selenium (Se) inputs to the San Francisco Bay-Delta Estuary (Bay-Delta), particularly in the North Bay (i.e., Suisun Bay and San Pablo Bay). These decisions may include discharge requirements for an extension of the San Luis Drain (SLD) to the estuary to convey subsurface agricultural drainage from the western San Joaquin Valley (SJV), a renewal of an agreement to allow the existing portion of the SLD to convey subsurface agricultural drainage to a tributary of the San Joaquin River (SJR) (coincident with changes in flow patterns of the lower SJR), and refinements to promulgated Se criteria for the protection of aquatic life for the estuary. Understanding the biotransfer of Se is essential to evaluating the fate and impact of proposed changes in Se discharges to the Bay-Delta. However, past monitoring programs have not addressed the specific protocols necessary for an element that bioaccumulates. Confusion about Se threats in the past have stemmed from failure to consider the full complexity of the processes that result in Se toxicity. Past studies show that predators are more at risk from Se contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. In this report, we employ a novel procedure to model the fate of Se under different, potentially realistic load scenarios from the SJV. For each potential load, we progressively forecast the resulting environmental concentrations, speciation, transformation to particulate form, bioaccumulation by invertebrates, trophic transfer to predators, and effects in those predators. Enough is known to establish a first order understanding of effects should Se be discharged directly into the North Bay via a conveyance such as the SLD. Our approach uses 1) existing knowledge concerning the biogeochemical reactions of Se (e.g., speciation, partitioning between dissolved and particulate forms, and bivalve assimilation efficiency) and 2) site-specific data mainly from 1986 to 1996 on clams and bottom-feeding fish and birds. Forecasts of Se loading from oil refineries and agricultural drainage from the SJV enable the calculation of a composite freshwater endmember Se concentration at the head of the estuary and at Carquinez Strait as a foundation for modeling. Our analysis of effects also takes into account the mode of conveyance for agricultural drainage (i.e., the SLD or SJR). The effects of variable flows on a seasonal or monthly basis from the Sacramento River and SJR are also considered. The results of our forecasts for external SJV watershed sources of Se mirror predictions made since 1955 of a worsening salt (and by inference, Se) buildup exacerbated by the arid climate and irrigation for agricultural use. We show that the reservoir of Se in the SJV is sufficient to provide loading at an annual rate of approximately 42,500 pounds (lbs) of Se to a Bay-Delta disposal point for 63 to 304 years at the lower range of our projections, even if influx of Se from the California Coast Ranges could be curtailed. Disposal of wastewaters on an annual basis outside of the SJV may slow the degradation of valley resources, but drainage alone cannot alleviate the salt and Se buildup in the SJV, at least within a century. Our forecasts show the different proportions of Se loading to the Bay-Delta. Oil refinery loads from 1986 to 1992 ranged from 11 to 15 lbs Se per day; with treatment and cleanup, loads decreased to 3 lbs Se per day in 1999. In contrast, SJV agricultural drainage loads could range from of 45 to 117 lbs Se per day across a set of reasonable conditions. Components of this valley-wide load include five source subareas (i.e., Grassland, Westlands, Tulare, Kern, and Northern) based on water and drainage management. Loads vary per subarea mainly because of proximity of the s

California↗

Too simple, too complex, or just right? Advantages, challenges, and guidance for indicators of genetic diversity

Measuring genetic diversity of wild species using DNA-based data remains resource intensive and time consuming for nearly all species. However, genetic assessments are needed for global conservation commitments, including the Convention on Biological Diversity, and for governments and managers to evaluate conservation progress, as well as prioritizing species and populations to preserve and recover genetic diversity (e.g., via genetic rescue). Recently, indicators were developed for tracking and reporting genetic diversity status and trends for hundreds of species. The indicators quantify two simple proxies of within-population and among-population genetic diversity and adaptive potential: small effective population size ( N e < 500) and the loss of genetically distinct populations. The indicators must balance scientific credibility, practicality, and simplicity. In the present article, we summarize the advantages of these pragmatic indicators, address critiques by scientists for simplifying assumptions and by policymakers for complexity, and propose potential solutions and next steps. We aim to support practitioners putting indicators into policy, action, legislation, and reporting.

BioScience↗

Water-quality trends for selected sites and constituents in the international Red River of the North Basin, Minnesota and North Dakota, United States, and Manitoba, Canada, 1970–2017

A comprehensive study to evaluate water-quality trends, while considering natural hydroclimatic variability, in the Red River of the North Basin and assess water-quality conditions for the Red River of the North crossing the international boundary near Emerson, Manitoba, Canada (the binational site), was completed by the U.S. Geological Survey in cooperation with the International Joint Commission, North Dakota Department of Environmental Quality, and Minnesota Pollution Control Agency and in collaboration with Manitoba Sustainable Development and Environment and Climate Change Canada. The international Red River of the North Basin encompasses 3 U.S. States (South Dakota, North Dakota, and Minnesota) and 1 Canadian Province (Manitoba). Water quality in the Red River of the North Basin is of concern for both Federal governments and State and Provincial governments. Water-quality objectives have been previously established for selected dissolved ions and recently (2019) proposed for selected nutrients for the binational site. In the current (2020) study, water-quality data from State, Provincial, and Federal agencies in the United States and Canada for sites in the Red River of the North Basin from 1970 to 2017 were compiled and used for trend analysis. Trend analysis using a water-quality dataset from multiple agencies that collect water-quality data for various objectives presented multiple challenges. The trend-analysis approach was able to accommodate differences in water-quality data caused by field-collection and laboratory-analytical method differences, disparities in sampling frequencies, and spatial and temporal gaps in data. Most of these challenges were overcome by the statistical tool, R–QWTREND, which identifies trends in concentration unrelated to variability in streamflow. The integrated basin approach used in the current study, combined with comparing current data trends with historical trends, provided valuable insights into understanding how water quality is changing spatially (34 sites analyzed for a recent period, 2000–15) and temporally (5 sites analyzed for a 45-year historical period, 1970–2015) within the Red River of the North Basin. One of the most consistent spatial and temporal changes observed in the current study was increasing concentrations of sulfate among tributary and main-stem sites since 2000. For some sites, increases were detected starting as early as 1985. Total dissolved solids and chloride concentrations had spatial and temporal patterns like sulfate. Although R–QWTREND removes the variability in constituent concentration caused by natural streamflow variability, all variability in sulfate caused by hydroclimatic variability may not be captured because of changes in hydrologic pathways and changes in the contributions of sulfate from various natural sources. Nutrient concentrations demonstrated less consistent spatial and temporal changes than sulfate, and changes in nutrient concentrations were assumed to be more closely tied to human-induced rather than natural changes. Nitrate-plus-nitrite concentrations were mostly increasing in the upper Red River of the North subbasin, and for nitrate plus nitrite and total nitrogen, the Sheyenne River subbasin had consistent decreasing concentrations. Since 2000, total phosphorus has decreased in the upper Red River of the North subbasin, but total phosphorus concentration has increased for sites in the lower Red River of the North subbasin, and for some main-stem sites, concentrations have been increasing since 1985. Unlike sulfate, the pattern in historical trends for total phosphorus for the main-stem sites differed from tributary sites, indicating that human-induced changes affected tributaries and main-stem sites differently. The more detailed evaluation of flow-averaged water-quality conditions for the binational site provided an understanding of how loads have changed over time and what proportion of the year and season concentrations are expected to exceed water-quality objectives. In a basin with highly variable streamflow like the Red River of the North, the trend in flow-averaged load (assuming streamflow conditions are the same year after year) provided a robust measure of change over time. Increasing concentrations of sulfate, chloride, total dissolved solids, and total phosphorus since 1985 for the binational site resulted in longer periods of exceedance of water-quality objectives per year occurring over time. For total nitrogen, decreasing concentrations resulted in shorter periods of exceedance per year during 1980 to 2015, but concentrations were still expected to exceed the water-quality objective about half the year. Periods of when exceedances were likely to occur during the year were affected by the source and transport mechanisms of the constituent. Trend results from this effort identified how water quality has changed across the basin, and further investigation would help to identify causes for the trends observed here. Information from the current study provides a basis for future trend attribution studies, evaluation of water-quality objectives, and development of comprehensive strategies for reducing nutrients to desired targets and establishes a baseline for tracking future progress in the Red River of the North Basin.

Minnesota, North Dakota, South Dakota, Manitoba↗

Ground-water level fluctuations in Utah, 1936-45

Ground-water investigations in Utah by the Geological Survey of the U.S. Department of the Interior have been in progress since 1935, in cooperation with the Utah State Engineer. This cooperative work includes (1) determination of the fluctuations of water level in most of the developed ground-water areas in the state, based upon measurements which are tabulated and published annually by the Geological Survey; and (2) detailed investigations of specific ground-water areas to determine source, movement, disposal, quantity and quality of the ground water, and to show the relation of present development to the maximum economic development of which those areas are capable. Such detailed investigations have been completed during the past decade for areas in Iron, Millard, Salt Lake, Tooele, and Weber Counties, and are referred to in discussion subsequently. Similar investigations are now in progress in other areas in Davis, Iron, and Weber Counties.

Utah↗

Annual compilation and analysis of hydrologic data for urban studies in the Austin, Texas Metropolitan Area, 1971

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, began hydrologic studies in the Austin urban area in 1954. The objectives of this project are as follows: 1. To determine the effects of progressive urbanization on infiltration, rates of peak discharge, and rainfall-runoff relations in the Waller Creek watershed. 2. To provide rainfall-and-runoff data from the rural Wilbarger Creek watershed to be used for comparative purposes in determining the effects of existing and progressive urbanization in the Waller Creek watershed. 3. To provide applied research facilities for studies at the University of Texas at Austin. The purpose of this report is to present rainfall-and-runoff data for the Waller Creek and Wilbarger Creek study areas for the 1971 water year (October 1, 1970, to September 30, 1971). To facilitate the publication and distribution of this report at the earliest feasible time, certain material has been included that does not conform to the formal publication standards of the U.S. Geological Survey.

Texas↗

Ground-water resources of the Houston district, Texas

This report covers the current phase of an investigation of the supply of ground water available for the Houston district and adjacent region, Texas,- that has been in progress during the past 10 years. The field operations included routine inventories of pumpage, measurements of water levels in observation wells and collection of other hydrologic data, pumping tests on 21 city-owned wells to determine coefficients of permeability and storage, and the drilling of 13 deep test wells in unexplored parts of the district. Considerable attention has been given to studies of the location of areas or beds of sand that contain salt water. The ground water occurs in beds of sand, sandstone, and gravel of Miocene, Pliocene, and Pleistocene age. These formations crop out in belts that dip southeastward from their outcrop areas and are encountered by wells at progressively greater depths toward the southeast. The beds throughout the section are lithologically similar, and there is little agreement among geologists as to their correlation. -In this investigation, however, the sediments, penetrated by the wells are separated into six zones, chiefly on the basis of electrical logs. Most of the water occurs in zone 3, which ranges in thickness from 800 to 1,200 feet. Large quantities of ground water are pumped in three areas in the Houston district, as follows: The Houston tromping area, which includes Houston and the areas immediately adjacent; the Pasadena pumping area, which includes the industrial section extending along the ship channel from the Houston city limits eastward to Deer Park; and the Katy pumping area, an irregular-shaped area of several hundred square miles, which is roughly centered around the town of Katy, 30 miles west of Houston. In 1930 the total combined withdrawal of ground water in the Houston and Pasadena pumping areas averaged about 50 million gallons a day. It declined somewhat during 1932 and 1933 and then gradually increased, until in 1935 the total pumpage was about the same as it was in 1930. About March 1, 1937, the pumpage was increased by about 40 percent, when new wells near Pasadena were put into operation. During 1940 it is estimated that the total pumpage in the Houston and Pasadena areas averaged about 79 million gallons a day, an increase of about 65 percent over the pumpage in 1935. About 25 million gallons of this increase has occurred in the Pasadena area. In the Katy rice-growing area the pumpage in 1935 was about 14 million gallons a day; in 1937 it was about 30 million gallons a day; in 1939 about 40 million gallons a day; and in 1940 about 45 million gallons a day. In 1940 the estimated total pumpage from the Houston, Pasadena, and Katy pumping areas was about 124 million gallons a day, or twice as much as it was in 1935. The increase in pumping at Pasadena in the spring-of 1937 caused the water leveling wells in the Houston and Pasadena areas, which had not varied materially for about 7 years, to decline at a rapid rate. Further increases in the pumping both at Houston and Pasadena in 1939 and 1940 has caused further substantial decline. The water levels in wells in the Katy rice-growing area also declined materially. The evidence points to the probability that in all parts of the Houston district, except the Katy rice-growing area, the rainfall is recharging the aquifers at a rate greater than that at which the water is transmitted down the dip. In the Katy area the recharge is insufficient to balance the joint discharge by transmission down the dip and withdrawal from rice-irrigating wells. The average coefficient of transmissibility was. calculated as 160,000 gallons a day. On the basis of these estimates the inflow in February 1940 across the artesian contour 10 feet below sea level (see pl. 10) was computed as 72 million gallons a day. The amount of water taken out of artesian storage in the 300-square mile area within the -10 contour during the period February 1939 to February

Water Supply Paper↗

Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in fifteen quadrangles in southwestern and west-central Alaska

These summaries of data on metallic and selected nonmetallic mineral occurrences and lists of selected references to them in Geological Survey, U.S. Bureau of Mines, and State of Alaska Division of Geological and Geophysical Surveys (and predecessor State and Territorial agencies) reports and maps released before Jan. 1, 1980, and in one abstract of a report presented orally at a scientific meeting, are designed to aid in library research on the mineral resources of 14 quadrangles in southwestern Alaska and the Saint Lawrence quadrangle in west—central Alaska. The references are selected in the sense that mainly statistical reports such as the annual Minerals Yearbook of the U.S. Bureau of Mines and many annual and biennial reports of the Alaska Division of Geological and Geophysical Surveys and its predecessor agencies are not included. Also not included are data on many claims about which little more than their locations is known (for example, localities 11 to 14 in MacKevett and Holloway, 1977 (OF 77-169D), p. 28). These omissions should not be interpreted as a judgement that the claims are not on valid mineral occurrences, but only that there are insufficient data to describe any mineral deposit that might be present. Geochemical anomalies determined by analyses of rock and stream—sediment samples in which no metallic mineral was identified are also omitted. Work now in progress should add greatly to the knowledge of mineral resources in several quadrangles on the Alaska Peninsula.

Alaska↗

Forecasting selenium discharges to the San Francisco Bay-Delta Estuary: Ecological effects of a proposed San Luis Drain extension

Selenium discharges to the San Francisco Bay-Delta Estuary (Bay-Delta) could change significantly if federal and state agencies (1) approve an extension of the San Luis Drain to convey agricultural drainage from the western San Joaquin Valley to the North Bay (Suisun Bay, Carquinez Strait, and San Pablo Bay); (2) allow changes in flow patterns of the lower San Joaquin River and Bay-Delta while using an existing portion of the San Luis Drain to convey agricultural drainage to a tributary of the San Joaquin River; or (3) revise selenium criteria for the protection of aquatic life or issue criteria for the protection of wildlife. Understanding the biotransfer of selenium is essential to evaluating effects of selenium on Bay-Delta ecosystems. Confusion about selenium threats to fish and wildlife stem from (1) monitoring programs that do not address specific protocols necessary for an element that bioaccumulates; and (2) failure to consider the full complexity of the processes that result in selenium toxicity. Past studies show that predators are more at risk from selenium contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. This report presents an approach to conceptualize and model the fate and effects of selenium under various load scenarios from the San Joaquin Valley. For each potential load, progressive forecasts show resulting (1) water-column concentration; (2) speciation; (3) transformation to particulate form; (4) particulate concentration; (5) bioaccumulation by invertebrates; (6) trophic transfer to predators; and (7) effects on those predators. Enough is known to establish a first-order understanding of relevant conditions, biological response, and ecological risks should selenium be discharged directly into the North Bay through a conveyance such as a proposed extension of the San Luis Drain. The approach presented here, the Bay-Delta selenium model, determines the mass, fate, and effects of selenium released to the Bay-Delta through use of (1) historical land-use, drainage, alluvial-fill, and runoff databases; (2) existing knowledge concerning biogeochemical reactions and physiological parameters of selenium (e.g., speciation, partitioning between dissolved and particulate forms, and bivalve assimilation efficiency); and (3) site-specific data mainly from 1986 to 1996 for clams and bottom-feeding fish and birds. Selenium load scenarios consider effluents from North Bay oil refineries and discharges of agricultural drainage from the San Joaquin Valley to enable calculation of (a) a composite freshwater endmember selenium concentration at the head of the estuary; and (b) a selenium concentration at a selected seawater location (Carquinez Strait) as a foundation for modeling. Analysis of selenium effects also takes into account the mode of conveyance for agricultural drainage (i.e., the San Luis Drain or San Joaquin River); and flows of the Sacramento River and San Joaquin River on a seasonal or monthly basis. Load scenarios for San Joaquin Valley mirror predictions made since 1955 of a worsening salt (and by inference, selenium) build-up exacerbated by an arid climate and massive irrigation. The reservoir of selenium in the San Joaquin Valley is sufficient to provide loading at an annual rate of approximately 42,500 pounds of selenium to a Bay-Delta disposal point for 63 to 304 years at the lower range of projections presented here, even if influx of selenium from the California Coast Ranges could be curtailed. Disposal of wastewaters on an annual basis outside of the San Joaquin Valley may slow the degradation of valley resources, but drainage alone cannot alleviate the salt and selenium build-up in the San Joaquin Valley, at least within a century. Load scenarios also show the different proportions of selenium loading to the Bay-Delta. Oil refinery loads from 1986 to 1992 ranged from 8.5 to 20 pounds of selenium per day; with treatment and cleanup, loads decreased to 3.0 pounds of selenium per day in 1999. In contrast, San Joaquin Valley agricultural drainage loads disposed of in a San Luis Drain extension could range from 45 to 117 pounds of selenium per day across a set of historical and future conditions. Components of this valley-wide load include five source subareas (i.e., Grassland, Westlands, Tulare, Kern, and Northern) defined by water and drainage management. Loads vary per subarea mainly because of proximity of the subarea to geologic sources of selenium and irrigation history. Loads from the Sacramento River, depending on flow conditions, range from 0.8 to 10 pounds of selenium per day. Loads from the San Joaquin River vary depending on restoration and flow conditions, which are considered. A consistent picture of ecological risk emerges under modeled selenium discharges from a proposed San Luis Drain extension. The threat to the estuary is greatest during low flow seasons and critically dry years. Where selenium undergoes reactions typical of low flow or longer residence time, highly problematic bioaccumulation in prey (food) is forecast. Surf scoter, greater and lesser scaup, and white sturgeon appear to be most at risk because these Bay-Delta predators feed on deposit and filter-feeding bivalves. Recent findings add Sacramento splittail and Dungeness crab to that list. During the low flow season of critically dry years, forecasted selenium concentrations in water, particulate matter, prey (diet), and predator tissue exceed guidelines with a high certainty of producing adverse effects under the most likely load scenario from a proposed San Luis Drain extension. High flows afford some protection under certain conditions in modeled San Joaquin River scenarios. However, meeting a combined goal of releasing a specific load during maximum flows and keeping selenium concentrations in the river below a certain objective to protect against bioaccumulation may not always be attainable. Management of the San Joaquin River on a constant concentration basis also could create problematic bioaccumulation during a wet year, especially during the low flow season, because high flows translate to high loads that are not always offset by seasonal river inflows. Prior to refinery cleanup, selenium contamination was sufficient to threaten reproduction in key species within the Bay-Delta ecosystems and human health advisories were posted based on selenium concentrations in tissues of diving ducks. During this time, selenium concentrations in the Bay-Delta were well below the most stringent recommended water quality criterion [1 microgram per liter (1 µg/L)]. Enhanced biogeochemical transformations to bioavailable particulate selenium and efficient bioaccumulation by bivalves characterized the system. If these biogeochemical conditions continue to prevail and agricultural selenium sources replace or exceed refinery sources, ecological forecasts suggest the risk of adverse effects will be difficult to eliminate under an out-of-valley resolution to the selenium problem. The Bay-Delta selenium model presented here is a systematic approach for conducting forecasts of the ecological effects from selenium on aquatic food webs. It is a new tool that links and models the major processes leading from loads through consumer organisms to predators. It also is a feasible approach for site-specific analysis and could provide a framework for developing new protective selenium foodweb guidelines and predator criteria. Model components that help ensure understanding ecosystems and the basis of environmental protection are (1) contaminant concentrations and speciation in sources, such as particulate material, that most influence bioavailability; (2) bioaccumulation models that calculate concentrations in diet, specifically in bivalves of the Bay-Delta that act as sensitive indicators of selenium contamination; (3) food-web type that determines what animals are threatened and when; and (4) multiple media concentrations (water, particulate material, and tissue of prey and predators) that, in-combination, determine risk or hazard.

California↗

Selenium and other elements in water and adjacent rock and sediment of Toll Gate Creek, Aurora, Arapahoe County, Colorado, December 2003 through March 2004

Streamwater and solid samples (rock, unconsolidated sediment, stream sediment, and efflorescent material) in the Toll Gate Creek watershed, Colorado, were collected and analyzed for major and trace elements to determine trace-element concentrations and stream loads from December 2003 through March 2004, a period of seasonally low flow. Special emphasis was given to selenium (Se) concentrations because historic Se concentrations exceeded current (2004) stream standards. The goal of the project was to assess the distribution of Se concentration and loads in Toll Gate Creek and to determine the potential for rock and unconsolidated sediment in the basin to be sources of Se to the streamwater. Streamwater samples and discharge measurements were collected during December 2003 and March 2004 along Toll Gate Creek and its two primary tributaries - West Toll Gate Creek and East Toll Gate Creek. During both sampling periods, discharge ranged from 2.5 liters per second to 138 liters per second in the watershed. Discharge was greater in March 2004 than December 2003, but both periods represent low flow in Toll Gate Creek, and results of this study should not be extended to periods of higher flow. Discharge decreased moving downstream in East Toll Gate Creek but increased moving downstream along West Toll Gate Creek and the main stem of Toll Gate Creek, indicating that these two streams gain flow from ground water. Se concentrations in streamwater samples ranged from 7 to 70 micrograms per liter, were elevated in the upstream-most samples, and were greater than the State stream standard of 4.6 micrograms per liter. Se loads ranged from 6 grams per day to 250 grams per day, decreased in a downstream direction along East Toll Gate Creek, and increased in a downstream direction along West Toll Gate Creek and Toll Gate Creek. The largest Se-load increases occurred between two sampling locations on West Toll Gate Creek during both sampling periods and between the two sampling locations on the main stem of Toll Gate Creek during the December 2003 sampling. These load increases may indicate that sources of Se exist between these two locations; however, Se loading along West Toll Gate Creek and Toll Gate Creek primarily was characterized by gradual downstream increases in load. Linear regressions between Se load and discharge for both sampling periods had large, significant values of r2 (r2 > 0.96, p < 0.0001) because increases in Se load (per unit of flow increase) were generally constant. This relation is evidence for a constant addition of water having a relatively constant Se concentration over much of the length of Toll Gate Creek, a result which is consistent with a ground-water source for the Se loads. Rock outcroppings along the stream were highly weathered, and Se concentrations in rock and other solid samples ranged from below detection (1 part per million) to 25 parts per million. One sample of efflorescence (a surface encrustation produced by evaporation) had the greatest selenium concentration of all solid samples, was composed of thenardite (sodium sulfate), gypsum (calcium sulfate) and minor halite (sodium chloride), and released all of its Se during a 30-minute water-leaching procedure. Calculations indicate there was an insufficient amount of this material present throughout the watershed to account for the observed Se load in the stream. However, this material likely indicates zones of ground-water discharge that contain Se. This report did not identify an unequivocal source of Se in Toll Gate Creek. However, multiple lines of evidence indicate that ground-water discharge supplies Se to Toll Gate Creek: (1) the occurrence of elevated Se concentrations in the stream throughout the watershed and in the headwater regions, upstream from industrial sources; (2) the progressive increase in Se loads moving downstream, which indicates a continuous input of Se along the stream rather than input from point sources; (3) the occurr

Colorado↗

Hydrologic studies of the U.S. Geological Survey related to coal development on Colorado

This report summarizes the hydrologic studies related to coal development being conducted by the U.S. Geological Survey in the State of Colorado. The objective of the hydrologic data-acquisition program is to collect surface-water quality and quantity data and ground-water level records. These data are needed to define predevelopment conditions and to monitor the effects of construction and operation of coal mines and waste-disposal areas. Data-acquisition activities related to coal development in Colorado have concentrated on the Yampa River basin. A description of the hydrologic data-acquisition activities, including parameters collected and frequency of collection, precedes the summaries of the three interpretive studies currently in progress. Each study summary consists of the project title, definition of the problem being studied, objective of the study, approach of the study, and when known, the schedule for completion of the study and proposed report products resulting from the study. (Woodard-USGS)

Open-File Report↗

Site-specific effects on productivity of an upper trophic-level marine predator: Bottom-up, top-down, and mismatch effects on reproduction in a colonial seabird

We investigated the relative roles of bottom-up and top-down factors in limiting productivity of an upper trophic level marine predator. Our primary working hypothesis was that the reproductive success of black-legged kittiwakes (Rissa tridactyla) a piscivorous, colonial-nesting seabird, was most limited by the abundance, distribution, and species composition of surface-schooling forage fishes. A secondary working hypothesis was that reproductive loss to kittiwake nest predators was greatest during years of reduced prey availability. We report on a broad-scale, integrated study of kittiwakes and their prey in Prince William Sound, Alaska. Our study spanned five breeding seasons (1995-1999) and focused on three colonies that differed in size (ranging from ca. 220 to ca. 7000 breeding pairs) and proximity to each other (50-135 km apart). Kittiwakes in PWS encountered a variety of aquatic habitats, creating a complex foraging environment for breeding birds. We measured kittiwake reproductive success and foraging activities, while simultaneously measuring the abundance of surface schooling forage fishes throughout the foraging range of breeding kittiwakes. The abundance of primary prey species for kittiwakes (Pacific herring Clupea pallasi, Pacific sand lance Ammodytes hexapterus, and capelin Mallotus villosus) varied both annually and regionally, with no one region consistently having the greatest abundance of prey. Likewise, kittiwake reproductive success varied considerably among colonies and years. We found that bottom-up, top-down, timing mismatch, and colony-specific effects were all important to kittiwake productivity. Although bottom-up effects appeared to be strongest, they were not evident in some cases until other effects, such as geographic location (proximity of colony to prey concentrations) and top-down predation, were considered. Important bottom-up effects on kittiwake reproductive success were not only total prey abundance and distribution, but also species, age composition, and chronology of prey occurrence (match/mismatch of timing with critical brood-rearing periods); these effects varied by colony. Top-down effects of predation on kittiwake nest contents (independent of prey abundance) confounded seabird-forage fish relationships. Ultimately, when confounding factors were minimized, non-linear asymptotic relationships were identified between kittiwakes and their prey, with an asymptotic threshold of fish school surface area density of ca. 5 m2/km2, beyond which top-down, physiological, or phylogenetic constraints likely restrict further reproductive output. The integrated approach of our investigations provided a more thorough understanding of the mechanisms underlying predator-prey relationships in the complex marine environment. However, such mechanistic theories can only be tested and refined through long-term research and monitoring of much greater duration than the 5-year study reported herein. ?? 2006 Elsevier Ltd. All rights reserved.

Progress in Oceanography↗

Man-made earthquakes and earthquake prediction

Convincing evidence that man can trigger earthquakes has been developed since the 1963–1967 report. The fact that man can start earthquakes has increased our understanding of earthquake mechanisms and reinforced our judgment that we are approaching the possibility of earthquake prediction. Traditionally, seismologists have avoided the subject of earthquake prediction because of its distasteful association with people who claim to be able to predict earthquakes by mystical nonscientific methods. Research on prediction has been intensified since the reports of the Panel on Earthquake Prediction [ Press , 1965] and the Interagency Working Group for Earthquake Research [ Pecora , 1968],. however, and it is appropriate to assess our progress toward that goal. Pakiser et al . [1969] and Oliver [1970] have also summarized recent U.S. progress toward earthquake prediction.

Eos Science News↗

Changes in yellow perch (Perca flavescens) populations of Lake Michigan, 1954-75

In the early and mid-1960s the abundance of yellow perch ( Perca flavescens ) in Lake Michigan declined abruptly. The decline began in the northern part of the lake and spread progressively southward. Circumstantial evidence suggests that the nonnative alewife ( Alosa pseudoharengus ), by interfering with perch reproduction, was the primary cause of the decline. The alewife was first reported in northeastern Lake Michigan in 1949, and had become extremely abundant throughout the lake before an enormous die-off in 1967 reduced its numbers by an estimated 70%. An intensive fishery hastened the decline of perch. In most areas the decline was immediately preceded by a period of conspicuously high commercial production. This high production appears to have been related in part to increased growth rates of perch resulting from much lower density of younger fish. A sport fishery for perch in shallow water collapsed a few years before the species declined in abundance. The most logical explanation is that heavy concentrations of alewives physically displaced the perch from nearshore areas. Although perch populations increased in some areas in the 1970s, a full recovery is unlikely unless alewife numbers are further reduced.

Journal of the Fisheries Research Board of Canada↗

Studies of transmission of mycobacterial infections in Chinook salmon

THE INCLUSION OF VISCERA AND CARCASSES OF TUBERCULOUS ADULT SALMON IN THE DIET OF JUVENILE SALMONIDS is considered to be the major source of mycobacterial infections in hatchery-reared fish (Wood and Ordal, 1958; Ross, Earp, and Wood, 1959). In considering additional modes of infection, we speculated about transovarian transmission or a mechanical process arising from contamination of the ova at the egg-taking stage with subsequent entry of the bacteria into the egg at the time of fertilization. This paper is a report on observations made during an experiment designed to test the latter theories.

Progressive Fish-Culturist↗

High Plains Regional Ground-water Study web site

Now available on the Internet is a web site for the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program-High Plains Regional Ground-Water Study. The purpose of the web site is to provide public access to a wide variety of information on the USGS investigation of the ground-water resources within the High Plains aquifer system. Typical pages on the web site include the following: descriptions of the High Plains NAWQA, the National NAWQA Program, the study-area setting, current and past activities, significant findings, chemical and ancillary data (which can be downloaded), listing and access to publications, links to other sites about the High Plains area, and links to other web sites studying High Plains ground-water resources. The High Plains aquifer is a regional aquifer system that underlies 174,000 square miles in parts of eight States (Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming). Because the study area is so large, the Internet is an ideal way to provide project data and information on a near real-time basis. The web site will be a collection of living documents where project data and information are updated as it becomes available throughout the life of the project. If you have an interest in the High Plains area, you can check this site periodically to learn how the High Plains NAWQA activities are progressing over time and access new data and publications as they become available.

Fact Sheet↗

Status of the National Water Data Exchange (NAWDEX) - September 1977

Major progress in the implementation of the National Water Data Exchange (Nawdex) took place during Fiscal Year 1977--beginning October 1, 1976 and ending September 30, 1977. This report describes the status of the program at the end of this period. Program advancement is reported in the areas of administration, membership, Local Assistance Center facilities, development of the Water Data Sources Directory and the Master Water Data Index data bases, development of systems related to these data bases, and the coordination of services available through member organizations.

Open-File Report↗

Hydrologic data for urban studies in the Dallas, Texas, metropolitan area, 1979

Hydrologic investigations of urban watersheds in Texas were begun by the U.S. Geological Survey in 1954. These studies are now in progress in Austin, Houston, and San Antonio. The study for the Fort Worth metropolitan area was completed at the end of the 1978 water year, and this report is the last annual report for the Dallas metropolitan area. Hydrologic data contained in this report and all previous reports of both the Dallas and Fort Worth metropolitan areas are being used to prepare an interpretive report entitled "Techniques for estimating the magnitude and frequency of floods in the Dallas-Fort Worth, Texas, metropolitan areas," which will be released in 1981.

Texas↗