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At least 1,387 records · Page 77Linked to original sources

USGS1998

Effect of activities at the Idaho National Engineering and Environmental Laboratory on the water quality of the Snake River Plain aquifer in the Magic Valley study

Radiochemical and chemical constituents in wastewater generated at facilities of the Idaho National Engineering and Environmental Laboratory (INEEL) (figure 1) have been discharged to waste-disposal ponds and wells since the early 1950 s. Public concern has been expressed that some of these constituents could migrate through the Snake River Plain aquifer to the Snake River in the Twin Falls-Hagerman area Because of these concerns the U.S. Department of Energy (DOE) requested that the U.S. Geological Survey (USGS) conduct three studies to gain a greater understanding of the chemical quality of water in the aquifer. One study described a one-time sampling effort for radionuclides, trace elements, and organic compounds in the eastern part of the A&B Irrigation District in Minidoka County (Mann and Knobel, 1990). Another ongoing study involves sampling for tritium from 19 springs on the north side of the Snake River in the Twin Falls-Hagerman area (Mann, 1989; Mann and Low, 1994). A third study an ongoing annual sampling effort in the area between the southern boundary of the INEEL and Hagerman (figure 1) (hereafter referred to as the Magic Valley study area), is being conducted with the Idaho Department of Water Resources in cooperation with the DOE. Data for a variety of radiochemical and chemical constituents from this study have been published by Wegner and Campbell (1991); Bartholomay, Edwards, and Campbell (1992, 1993, 1994a, 1994b); and Bartholomay, Williams, and Campbell (1995, 1996, 1997b). Data discussed in this fact sheet were taken from these reports. An evaluation of data collected during the first four years of this study (Bartholomay Williams, and Campbell, 1997a) showed no pattern of water-quality change for radionuclide data as concentrations randomly increased or decreased. The inorganic constituent data showed no statistical change between sample rounds.

Idaho↗

USGS2016

Does resolution of flow field observation influence apparent habitat use and energy expenditure in juvenile coho salmon?

This study investigated how the resolution of observation influences interpretation of how fish, juvenile Coho Salmon ( Oncorhynchus kisutch ), exploit the hydraulic environment in streams. Our objectives were to evaluate how spatial resolution of the flow field observation influenced: (1) the velocities considered to be representative of habitat units; (2) patterns of use of the hydraulic environment by fish; and (3) estimates of energy expenditure. We addressed these objectives using observations within a 1:1 scale physical model of a full-channel log jam in an outdoor experimental stream. Velocities were measured with Acoustic Doppler Velocimetry at a 10 cm grid spacing, whereas fish locations and tailbeat frequencies were documented over time using underwater videogrammetry. Results highlighted that resolution of observation did impact perceived habitat use and energy expenditure, as did the location of measurement within habitat units and the use of averaging to summarize velocities within a habitat unit. In this experiment, the range of velocities and energy expenditure estimates increased with coarsening resolution (grid spacing from 10 to 100 cm), reducing the likelihood of measuring the velocities locally experienced by fish. In addition, the coarser resolutions contributed to fish appearing to select velocities that were higher than what was measured at finer resolutions. These findings indicate the need for careful attention to and communication of resolution of observation in investigating the hydraulic environment and in determining the habitat needs and bioenergetics of aquatic biota.

Water Resources Research↗

USGS2021

Cooperative Fish and Wildlife Research Units program—2020 research abstracts

The U.S. Geological Survey (USGS) serves as the research arm of the U.S. Department of the Interior and has established a series of strategic goals that focus its efforts on serving the American people. Within the USGS, the Ecosystems Mission Area is responsible for conducting and sponsoring research that addresses the following thematic objectives under the overarching strategic goal of “Science that Supports Our Resources in Wild and Urban Spaces, and the Landscapes In-Between”: Science supporting a legacy of sustainable fish and wildlife, Social science and human components in land, water, and wildlife conservation, Trusted science supporting hard decisions on at-risk species, Science to battle costly biological threats, Providing science for managing risks and responding to extreme events, Science for preservation and restoration of iconic landscapes, and Science to support adaptation and address impacts of climate and land change. This report provides abstracts of most of the ongoing and recently completed research investigations of the USGS Cooperative Fish and Wildlife Research Units program. The report is organized by the following major science themes that contribute to the objectives of the USGS: Advanced Technologies Climate Science Decision Science Ecological Flows Ecosystem Services Energy Fish and Wildlife Health and Disease Human Dimensions Invasive Species Landscape Ecology Species and Habitat Management Species of Greatest Conservation Need Threatened and Endangered Species

Circular↗

USGS1962

Ground-water investigations of the Project Gnome area, Eddy and Lea Counties, New Mexico

The U.S. Atomic Energy Commission, through the Office of Test Operations, Albuquerque Operations Office, plans to detonate a nuclear device in a massive salt bed 1,200 feet beneath the land surface. The project, known as Project Gnome, is an element of the Plowshare program--a study of peacetime applications of nuclear fission. The location of the proposed underground shot is in a sparsely-populated area in southeastern Eddy County, N. Mex., east of the Pecos River and about 25 miles southeast of the city of Carlsbad. The area is arid to Semiarid and ground water is a vital factor in the economic utilization of the land, which is primarily used for stock raising. An investigation of the Project Gnome site and surrounding area for the purposes of evaluating the ground-water resources and the possible effect upon them from the detonation of the nuclear shot was desired by the Commission. This report describes work done by the U.S. Geological Survey on behalf of the Commission and presents results of the investigation of the ground-water resources and geology of the area. The most intensive investigations were made within a 15-mile radius of the site of Project Gnome and mainly on the east side of the Pecos River. The total area of study of over 1,200 square miles includes parts of Eddy and Lea Counties, N. Mex. The Project Gnome site is in the sedimentary Delaware Basin. It is underlain by about 18,000 feet of sedimentary rocks ranging in age from Ordovician to Recent. Upper Permian evaporitic rocks, which contain the principal source of potash available in the United States, are worked in nearby mines. The potash minerals are found in a massive salt bed about 1,400 feet thick in the Salado Formation of Permian age. The land surface of the area is covered mostly by a wind-blown sand and caliche; however, rocks of the Rustler Formation of Permian age and younger rocks of Permian, Triassic, Pleistocene(?) and Recent age crop out at several localities. Solution by ground water of salt at the top of the Salado Formation and of anhydrite within the Rustler Formation has removed thick sections of these rocks. A subsequent lowering of the land surface and differential collapse of the Rustler has formed many sinkholes and has created a karst topography over much of the western part of the area. Ground water is obtained from rocks of Permian, Triassic, Tertiary, and Quaternary age in the general region. However, the only aquifer at the Gnome site is the Culebra Dolomite Member of the Rustler Formation of Permian age. The aquifer is about 500 feet beneath the surface at the site and is about 30 feet thick. An aquifer, immediately above the top of the salt, contains a brine solution in Nash Draw, a few miles west of the Gnome site. This aquifer discharges into the Pecos River and is a major source of contamination of the river water. No potable water is known to be present in the area below the top of the salt of the Salado Formation. The ground water in the area is generally under artesian pressure. The general direction of ground-water movement is toward the Pecos River both east and west of the river. At the Gnome site the artesian head of the water in the Culebra Dolomite Member is about 7.5 feet. The water moves westward through the aquifer at a rate of about ? foot per day. The most widespread utilization of ground water east of the river is for stock use. Irrigation usage west of the Pecos River accounts for the largest withdrawal of water. Wells range in depth from a few tens of feet to nearly 800 feet. Water levels range from a few feet to about 500 feet below the surface. A test well at the Gnome site drawing water from the Culebra Dolomite Member was pumped at a rate of 100 gpm (gallons per minute); however, most wells east of the river yield only a few gpm. Irrigation wells west of the river yield as much as 3,500 gpm. Most of the water in the area is highly mineralized and is suitable only for use by livest

Open-File Report↗

USGS2009

Coal-to-liquids: Potential impact on U.S. coal reserves

The production of liquid fuels from coal will very likely become an important part of the hydrocarbon energy mix of the future, provided that technical and environmental obstacles are overcome economically. The coal industry should be able to handle a coal-to-liquids (CTL) industry of modest size, using 60-70 million short tons or 54-64 million metric tonnes of coal per annum, without premature depletion of the country's coal reserves. However, attempts to use CTL technology to replace all petroleum imports would deplete the nation's coal reserves by the end of the century. ?? 2009 U.S. Government.

Natural Resources Research↗

USGS2018

Summary of wildlife-related research on the coastal plain of the Arctic National Wildlife Refuge, Alaska, 2002–17

We summarize recent (2002–17) publicly available information from studies within the 1002 Area of the Arctic National Wildlife Refuge as well as terrestrial and coastal ecosystems elsewhere on the Arctic Coastal Plain that are relevant to the 1002 Area. This report provides an update on earlier research summaries on caribou (Rangifer tarandus), forage quality and quantity, polar bears (Ursus maritimus), muskoxen (Ovibos moschatus), and snow geese (Chen caerulescens). We also provide information on new research related to climate, migratory birds, permafrost, coastal erosion, coastal lagoons, fish, water resources, and potential effects of industrial disturbance on wildlife. From this literature review, we noted evidence for change in the status of some wildlife and their habitats, and the lack of change for others. In the 1002 Area, muskox numbers have decreased and the Porcupine Caribou Herd has exhibited variation in use of the area during the calving season. Polar bears are now more common on shore in summer and fall because of declines in sea ice in the Beaufort Sea. In a study spanning 25 years, there were no significant changes in vegetation quality and quantity, soil conditions, or permafrost thaw in the coastal plain of the 1002 Area. Based on studies from the central Arctic Coastal Plain, there are persistent and emerging uncertainties about the long-term effects of energy development for caribou. In contrast, recent studies that examined direct and indirect effects of industrial activities and infrastructure on birds in the central Arctic Coastal Plain found little effect for the species and disturbances examined, except for the possibility of increased predator activity near human developments.

Alaska↗

USGS1996

Evapotranspiration from successional vegetation in a deforested area of the Lake Wales Ridge, Florida

The suitability of three evapotranspiration models (Penman-Monteith, Penman, and a modified Priestley-Taylor) was evaluated at a site of successional vegetation in a deforested area of the Lake Wales Ridge, Florida. Eddy correlation measurements of evapotranspiration made during 22 approximately 1-day periods at a temporal resolution of 20 minutes from September 1993 to August 1994 were used to calibrate the evapotranspiration models. Three variants of the eddy correlation method that ascribe measurement error to three different sources were considered in the analysis. The Penman-Monteith and modified Priestley- Taylor models were successful in approximating measured 20-minute values of evapotranspiration (r 2 ≥0.918). The most successful approaches were the modified Priestley-Taylor model (r 2 =0.972) and a nontraditional and simplified form of the Penman-Monteith model (r 2 =0.967). The Penman approach was unsuccessful as a predictor of evapotranspiration. The evapotranspiration models were used to estimate evapotranspiration between measurements. When evapotranspiration values measured with a Bowen ratio variant of the eddy correlation method were used for model calibration, estimated daily evapotranspiration rates varied seasonally ranging from 0.2 millimeters per day (0.008 inch per day) in late December 1993 to 5 millimeter per day (0.2 inch per day) in mid-July 1994. Annual evapotranspiration (September 15, 1993, to September 15, 1994) was estimated to be about 680 millimeters (27 inches). Evapotranspiration models calibrated to the standard eddy correlation method and to an energy-balance residual variant provided estimates of annual evapotranspiration that were about 10 per cent lower and higher, respectively. These data indicate that of the 1,320 millimeters (52 inches) of precipitation during the 1-year period, about 570 to 700 millimeters (22 to 28 inches) recharged the surficial aquifer. Evapotranspiration at this study site probably defines the lower limit of evapotranspiration from vegetated surfaces in central Florida because of the shallow-rooted plants, rapidly-drained soils, and relatively deepwater table.

Florida↗

USGS2009

Diets of aquatic birds reflect changes in the Lake Huron ecosystem

Human activities have affected the Lake Huron ecosystem, in part, through alterations in the structure and function of its food webs. Insights into the nature of food web change and its ecological ramifications can be obtained through the monitoring of high trophic level predators such as aquatic birds. Often, food web change involves alterations in the relative abundance of constituent species and/or the introduction of new species (exotic invaders). Diet composition of aquatic birds is influenced, in part, by relative prey availability and therefore is a sensitive measure of food web structure. Using bird diet data to make inferences regarding food web change requires consistent measures of diet composition through time. This can be accomplished by measuring stable chemical and/or biochemical “ecological tracers” in archived avian samples. Such tracers provide insights into pathways of energy and nutrient transfer. In this study, we examine the utility of two groups of naturally-occurring intrinsic tracers (stable isotopes and fatty acids) to provide such information in a predatory seabird, the herring gull ( Larus argentatus ). Retrospective stable nitrogen and carbon isotope analysis of archived herring gull eggs identified declines in gull trophic position and shifts in food sources in Lake Huron over the last 25 years and changes in gull diet composition were inferred from egg fatty acid patterns. These independent groups of ecological tracers provided corroborating evidence of dietary change in this high trophic level predator. Gull dietary shifts were related to declines in prey fish abundance which suggests large-scale alterations to the Lake Huron ecosystem. Dietary shifts in herring gulls may be contributing to reductions in resources available for egg formation. Further research is required to evaluate how changes in resource availability may affect population sustainability in herring gulls and other waterbird species. Long-term biological monitoring programs are required to identify ecosystem change and evaluate its ecological significance.

Lake Huron↗

USGS1997

Evaluation of agricultural best-management practices in the Conestoga River headwaters, Pennsylvania: Effects of pipe-outlet terracing on quantity and quality of surface runoff and ground water in a small carbonate-rock basin near Churchtown, Pennsylvania, 1983-89

Terracing effects on surface-runoff and ground- water quantity and quality were investigated by the U.S. Geological Survey, in cooperation with Pennsylvania Department of Environmental Resources, during 1983-89 at a 23.1-acre agricultural site in Lancaster County, Pa., as part of the 1982 Rural Clean Water Program. The site, underlain by carbonate rock, was primarily corn and alfalfa fields; the median slope was 6 percent.Normal precipitation is about 42 inches per year. Average annual runoff was 11 percent and ground- water recharge was 37 percent of precipitation.Runoff quantity, suspended-sediment, and nutrient data, ground-water level and nutrient data, and precipitation-quantity data were collected for 21 months prior to, and 58 months after, pipe-outlet terrace construction. Data were analyzed by use of graphical, regression, covariate, cluster, Mann- Whitney Rank Sum test, and double-mass curvetechniques. Terracing changed runoff characteristics. Storm characteristics were similar throughout the study period. However, after terracing, storms producing less than 0.4 inch of precipitation rarely produced runoff. Total-storm discharge as a function of precipitation did not change significantly throughout the range of runoff-producing storms after terracing. Multiple-discharge peaks on hydrographs before terracing did not occur after terracing when hydrographs reflected the stepwisedraining of each terrace through the pipe outlet. After an initial 2-year period of terrace stabilization, suspended-sediment yield in runoff decreased significantly as a function of runoff. This result was expected because terracing decreased runoff energy, and because terrace ponding allowed time for sediment redeposition. Nitrate plus nitrite yields increased proportionally throughout the range of runoff during the post-terracing period relative to the pre- terracing period. After terracing, a combination of increased soil contact time and increased nitrification caused by wetter soils is believed to have increased nitrate concentrations in runoff. No significant change was found in yields of total nitrogen, ammonia plus organic nitrogen, or total phosphorus relative to runoff before and after terracing. Limited data suggest that fine-sediment particles (less than 0.62 micrometers in diameter), which continued to be discharged from the site, transported most of the phosphorus. Terracing did not significantly change the quantity of recharge to the carbonate aquifer. The mean annual water-table altitude did not change after terracing. Nitrate concentrations of ground water increased significantly at four of the site wells after terracing, probably because of increased contact time of the recharge with nutrient-rich soils in ponded terrace water. Qualitative evidence indicates that large decreases in nutrient requirements and nitrogen applications because of a crop change from corn to alfalfa upgradient of two site wells resulted in either no detectable change or a significant decrease in nitrate concentrations of ground water after terracing.

Pennsylvania↗

USGS1982

Reconnaissance geologic map and mineral resource potential of the Gearhart Mountain Wilderness and Roadless Area (6225), Lake and Klamath counties, Oregon

The Gearhart Mountain Wilderness, Lake and Klamath Counties, Oreg., is devoid of mines and mineral prospects and there are no known mining claims within the area. Furthermore, the results of this mineral appraisal indicate that there is little likelihood that commercial deposits of metallic minerals will be found in the area. Commercial uranium deposits, like those at the White King and Lucky Lass mines about 16 mi (~25 km) to the southeast of the wilderness, and deposits of mercury, like those south-southeast of the wilderness, are not likely to be found within the wilderness, even though all of these areas are characterized by middle and late Cenozoic intrusive and extrusive volcanic rocks. Rock of low commercial value for construction purposes is present, but better and more accessible deposits are present in adjacent regions. There is no evidence to indicate that mineral fuels are present in the area. Higher than normal heat floe characterizes the region containing Gerheart Mountain, indicating that it may have some, as yet undefined, potential for the development of geothermal energy. Data are not available to determine whether this higher than normal heat flow is meaningful in terms of a potential energy source or as a guide to possible future exploration; lack of thermal springs or other evidence of localized geothermal anomalies within the Gerhart Mountain suggest, however, that the potential for the development of geothermal energy is probably low.

Oregon↗

USGS1978

Lithium, a preliminary survey of its mineral occurrence in flint clay and related rock types in the United States

Maximum concentrations of lithium found in samples of flint clay and associated rocks of Pennsylvanian age in different States, in parts per million (ppm), are: Missouri, 5100; Pennsylvania-Maryland, 2100; Kentucky, 890; Ohio, 660; Alabama, 750; and Illinois, 160. Lithium-bearing kaolin deposits are distributed in the Coastal Plain province from New Jersey to Texas, and one occurs in Idaho; maximum lithium concentrations in samples from these deposits range from 64 to 180 ppm. The maximum concentration found in the Arkansas bauxite region is 460 ppm and that in flint clay in Colorado is 370 ppm. Samples from areas other than Pennsylvania, Maryland, Kentucky and Missouri are relatively few in number, represent mostly commercially valuable clays, and represent only a part of the refractory clay deposits in the United States. Data are not available on the clays associated with these deposits that may be unusable because they contain too much lithium as well as other deleterious elements. In both Pennsylvania and Missouri, lithium contents vary regionally between districts and locally between deposits. In samples containing more than 2000 ppm lithium, the lithium occurs in a dioctahedral chlorite mineral very similar to cookeite, which previously has not been recognized in sedimentary clays. The associated clays consist chiefly of well-crystallized kaolinite. The dioctahedral chlorite, however, seems to be most abundant where diaspore and boehmite occur along with the kaolinite. Barium, chromium, copper, phosphorus and strontium are present in some samples in amounts of several hundred pans per million or more, and may contribute to the failure of some clays to perform satisfactorily in firing tests. Lithium-rich clays could serve as a significant lithium resource in the very distant future. Clays that contain as much as 1% lithium may be common enough in Missouri or in Pennsylvania to be produced as a by-product to help support benefication costs for refractory clays. Sufficient amounts of lithium-rich clay may be found in deposits that have been explored, found unsatisfactory for normal refractory uses, and not developed. The lithium-rich clay in some deposits presently being worked may be worth stockpiling for eventual use.

Energy↗

USGS2024

Utica/Point Pleasant brine isotopic compositions (δ7Li, δ11B, δ138Ba) elucidate mechanisms of lithium enrichment in the Appalachian Basin

Global Li production will require a ~500 % increase to meet 2050 projected energy storage demands. One potential source is oil and gas wastewater (i.e., produced water or brine), which naturally has high total dissolved solids (TDS) concentrations, that can also be enriched in Li (>100 mg/L). Understanding the sources and mechanisms responsible for high naturally-occurring Li concentrations can aid in efficient targeting of these brines. The isotopic composition (δ 7 Li, δ 11 B, δ 138 Ba) of produced water and core samples from the Utica Shale and Point Pleasant Formation (UPP) in the Appalachian Basin, USA indicates that depth-dependent thermal maturity and water-rock interaction, including diagenetic clay mineral transformations, likely control Li concentrations. A survey of Li content in produced waters throughout the USA indicates that Appalachian Basin brines from the Marcellus Shale to the UPP have the potential for economic resource recovery.

Maryland, Ohio, Pennsylvania, West Virginia↗

USGS2011

USGS global change science strategy: A framework for understanding and responding to climate and land-use change

This U.S. Geological Survey (USGS) Global Change Science Strategy expands on the Climate Variability and Change science component of the USGS 2007 Science Strategy, “Facing Tomorrow’s Challenges: USGS Science in the Coming Decade” (U.S. Geological Survey, 2007). Here we embrace the broad definition of global change provided in the U.S. Global Change Research Act of 1990 (Public Law 101–606,104 Stat. 3096–3104)—“Changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life”—with a focus on climate and land-use change. There are three major characteristics of this science strategy. First, it addresses the science required to broadly inform global change policy, while emphasizing the needs of natural-resource managers and reflecting the role of the USGS as the science provider for the Department of the Interior and other resource-management agencies. Second, the strategy identifies core competencies, noting 10 critical capabilities and strengths the USGS uses to overcome key problem areas. We highlight those areas in which the USGS is a science leader, recognizing the strong partnerships and effective collaboration that are essential to address complex global environmental challenges. Third, it uses a query-based approach listing key research questions that need to be addressed to create an agenda for hypothesis-driven global change science organized under six strategic goals. Overall, the strategy starts from where we are, provides a vision for where we want to go, and then describes high-priority strategic actions, including outcomes, products, and partnerships that can get us there. Global change science is a well-defined research field with strong linkages to the ecosystems, water, energy and minerals, natural hazards, and environmental health components of the USGS Science Strategy (2007). When science strategies that cover these other components are developed, coordinated implementation will be necessary to achieve Bureau-level synergies and optimize capabilities and expertise. In October 2010, USGS realigned its management and budget structure to implement its 2007 Science Strategy. The new organizational structure, in which “Global Change” is one of seven key mission areas, lends itself to the advancement of the established six strategic goals. USGS global change science is formally represented by the “Climate and Land-Use Change” Mission Area in the FY 2012 budget (USGS, 2011). This plan was developed by the USGS Global Change Science Strategy Planning Team (SSPT) appointed by the USGS Director on March 4, 2010 and charged with developing a Global Change Science Strategy for the coming decade (McNutt, 2010). USGS managers and science staff are the main audience for this science strategy. This document is also intended to serve as the foundation for consistent USGS collaboration and communication with partners and stakeholders.

Open-File Report↗

USGS1983

Water-resources investigations of the U.S. Geological Survey in New Mexico; fiscal year 1981

The Water Resources Division of the U.S. Geological Survey investigates the occurrence, quantity, quality, distribution, and movement of the Nation 's surface and underground waters, and coordinates Federal water data acquisition activities. During fiscal year 1981, the New Mexico District had 40 active projects, released 19 reports, and answered hundreds of requests of water-related information. Investigations included the following: (1) chemical quality of surface water in New Mexico; (2) chemical quality of groundwater in New Mexico; (3) sediment transport in New Mexico streams; (4) surface water supply; (5) surface water diversions for irrigation; (6) streamflow characteristics; (7) effect of urban development on storm runoff; (8) inundation from floods; (9) effects of groundwater pumping; (10) long-term monitoring of groundwater levels; (11) groundwater and surface water relationships; (12) consumptive use by phreatophytes; (13) hydrologic impacts of energy development; and (14) groundwater supplies. (Lantz-PTT)

Open-File Report↗

USGS2010

Wyoming Landscape Conservation Initiative Science and Management Workshop Proceedings, May 12-14, 2009, Laramie, Wyoming

The U.S. Geological Survey (USGS) hosted the second Wyoming Landscape Conservation Initiative (WLCI) Science and Management Workshop at the University of Wyoming Conference Center and Hilton Garden Inn on May 12, 13, and 14, 2009, in Laramie, Wyo. The workshop focused on six topics seen as relevant to ongoing WLCI science and management activities: mapping and modeling resources for decisionmaking; data information and management; fish and wildlife research; changing landscapes; monitoring; and reclamation and offsite mitigation. Panelists gave presentations on ongoing research in these six areas during plenary sessions followed by audience discussions. Three breakout groups focused on discussing wildlife, reclamation, and monitoring. Throughout the plenary sessions, audience discussions, and breakout groups, several needs were repeatedly emphasized by panelists and workshop participants: developing a conservation plan and identifying priority areas and species for conservation actions; gaining a deeper understanding of sagebrush ecology; identifying thresholds for wildlife that can be used to create an 'early warning system' for managers; continuing to collect basic data across the landscape; facilitating even greater communication and partnership across agencies and between scientists and land managers; and engaging proactively in understanding new changes on the landscape such as wind energy development and climate change. Detailed proceedings from the workshop are captured and summarized in this report.

Scientific Investigations Report↗

USGS2014

Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels ( Dreissena spp.), spiny water flea ( Bythotrephes longimanus ), round goby ( Neogobius melanostomus )) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis , burbot ( Lota lota ), phytoplankton, alewife ( Alosa pseudoharengus ), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha ). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

Lake Michigan↗

USGS2018

Integrated diet analyses reveal contrasting trophic niches for wild and hatchery juvenile Chinook Salmon in a large river delta

Hatchery programs have been used as a conservation tool to bolster declining populations of Chinook Salmon Oncorhynchus tshawytscha along much of the North American Pacific coast. In many watersheds, hatchery stocks are released concurrently with the wild population, thus raising the potential for density‐dependent effects. Competition for prey resources during the critical period for early marine growth and survival may diminish the foraging capacity and growth potential of wild Chinook Salmon, highlighting the importance of a diverse and productive delta habitat mosaic. We used an integrated diet approach with stomach content and stable isotope analyses to evaluate contrasting patterns of habitat use and prey consumption in a fall‐run population of juvenile Chinook Salmon from the Nisqually River delta in Puget Sound, Washington. We examined size‐class and origin‐level differences throughout a gradient of delta habitat types. Wild (unmarked) and hatchery juveniles exhibited distinct habitat use patterns whereby unmarked fish were captured more frequently in tidally influenced freshwater and mesohaline emergent marsh areas, while hatchery fish were caught more often in the nearshore intertidal zone. Consequently, hatchery fish were less likely to consume the energy‐dense terrestrial insects that were more common in freshwater and brackish marshes. Stable isotope signatures from muscle and liver tissues corroborated this finding, showing that unmarked juveniles had derived 24–31% of their diets from terrestrially sourced prey, while terrestrial insects only made up 2–8% of hatchery fish diets. This may explain why unmarked fish were in better condition than hatchery fish and had stomach contents that were 15% more energy‐rich than those of hatchery fish. We did not observe strong evidence for trophic overlap in juvenile Chinook Salmon of different rearing origins, but our results suggest that hatchery juveniles could be more sensitive to diet‐mediated effects on growth and survival.

Washington↗

USGS2017

Rare-earth elements

The rare-earth elements (REEs) are 15 elements that range in atomic number from 57 (lanthanum) to 71 (lutetium); they are commonly referred to as the “lanthanides.” Yttrium (atomic number 39) is also commonly regarded as an REE because it shares chemical and physical similarities and has affinities with the lanthanides. Although REEs are not rare in terms of average crustal abundance, the concentrated deposits of REEs are limited in number. Because of their unusual physical and chemical properties, the REEs have diverse defense, energy, industrial, and military technology applications. The glass industry is the leading consumer of REE raw materials, which are used for glass polishing and as additives that provide color and special optical properties to the glass. Lanthanum-based catalysts are used in petroleum refining, and cerium-based catalysts are used in automotive catalytic converters. The use of REEs in magnets is a rapidly increasing application. Neodymium-iron-boron magnets, which are the strongest known type of magnets, are used when space and weight are restrictions. Nickel-metal hydride batteries use anodes made of a lanthanum-based alloys. China, which has led the world production of REEs for decades, accounted for more than 90 percent of global production and supply, on average, during the past decade. Citing a need to retain its limited REE resources to meet domestic requirements as well as concerns about the environmental effects of mining, China began placing restrictions on the supply of REEs in 2010 through the imposition of quotas, licenses, and taxes. As a result, the global rare-earth industry has increased its stockpiling of REEs; explored for deposits outside of China; and promoted new efforts to conserve, recycle, and substitute for REEs. New mine production began at Mount Weld in Western Australia, and numerous other exploration and development projects noted in this chapter are ongoing throughout the world. The REE-bearing minerals are diverse and often complex in composition. At least 245 individual REE-bearing minerals are recognized; they are mainly carbonates, fluorocarbonates, and hydroxylcarbonates (n = 42); oxides (n = 59); silicates (n = 85); and phosphates (n = 26). Many of the world’s significant REE deposits occur in carbonatites, which are carbonate igneous rocks. The REEs also have a strong genetic association with alkaline magmatism. The systematic geologic and chemical processes that explain these observations are not well understood. Economic or potentially economic REE deposits have been found in (a) carbonatites, (b) peralkaline igneous systems, (c) magmatic magnetite-hematite bodies, (d) iron oxide-copper-gold (IOCG) deposits, (e) xenotime-monazite accumulations in mafic gneiss, (f) ion-absorption clay deposits, and (g) monazite-xenotime-bearing placer deposits. Carbonatites have been the world’s main source for the light REEs since the 1960s. Ion-adsorption clay deposits in southern China are the world’s primary source of the heavy REEs. Monazite-bearing placer deposits were important sources of REEs before the mid-1960s and may be again in the future. In recent years, REEs have been produced from large carbonatite bodies mined at the Mountain Pass deposit in California and, in China, at the Bayan Obo deposit in Nei Mongol Autonomous Region, the Maoniuping deposit in Sichuan Province, the Daluxiang deposit in Sichuan Province, and the Weishan deposit in Anhui Province. Alkaline igneous complexes have recently been targeted for exploration because of their enrichments in the heavy REEs. Information relevant to the environmental aspects of REE mining is limited. Little is known about the aquatic toxicity of REEs. The United States lacks drinking water standards for REEs. The concentrations of REEs in environmental media are influenced by their low abundances in crustal rocks and their limited solubility in most groundwaters and surface waters. The scarcity of sulfide minerals, including pyrite, minimizes or eliminates concerns about acid-mine drainage for carbonatite-hosted deposits and alkaline-intrusion-related REE deposits. For now, insights into environmental responses of REE mine wastes must rely on predictive models.

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