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At least 739 records · Page 41Linked to original sources
USGS2016

Shifting currents: Progress, setbacks, and shifts in policy and practice

The Wisconsin Academy’s initial Waters of Wisconsin project (WOW I) facilitated a statewide conversation between 2000 and 2003 around one main question: How can we ensure healthy aquatic ecosystems and clean, abundant water supplies for tomorrow’s Wisconsin? Robust participation in this conversation underscored the important role citizens have in the stewardship of our waters, and we found enthusiastic support for farsighted policies—based on sound science—to manage our water legacy. Overall, we found that Wisconsinites cherish water and see our waters as essential to our way of life in Wisconsin. Nationally, our state ranks 25th in land area but has the fourth-highest area covered by water. Wisconsin is 20th in population but is second only to Florida in the number of fishing licenses sold each year. Clean water supports billions of dollars’ worth of economic activity through tourism, agriculture, and industry. From the Northwoods cabin to the Port of Milwaukee to the Wisconsin Dells, water shapes our state’s identity. Our tradition of safeguarding Wisconsin’s waters is grounded in values such as responsibility to family and future generations, respect for land and wildlife, protecting public health and safety, and caring for water as a common good, as articulated in the state’s Public Trust Doctrine (see page 9). These deeply held values have also shaped a conservation ethic, and its legacy has served many generations who depend upon and enjoy the waters of the state. Through WOW I, we identified the need to overcome the institutional and disciplinary separation of science, policy, and management protocols through a more integrated approach to water management. WOW also affirmed that the Wisconsin Department of Natural Resources (DNR) and other public agencies play a critical role in sound scientific application, citizen participation, and the practical implementation of policy while balancing public and private interests toward the goal of a clean water future. More than a decade has passed since our first statewide WOW conversation and the report that captured recommendations from its participants: Waters of Wisconsin: The Future of Our Aquatic Ecosystems and Resources. Drawing from a diverse and growing set of stakeholders from across the state, the Wisconsin Academy initiated a new conversation in 2012 (known as WOW II) to assess progress in regard to our 2003 recommendations. We also sought to review the status of waters in Wisconsin today. The result of this renewed conversation is Shifting Currents: Progress, Setbacks, and Shifts in Policy and Practice. The new report assesses progress in brief, and explores in greater depth the continuing and emerging challenges to water quality, supply, and aquatic ecosystems in Wisconsin. In this report, we first review the context and frameworks for public decision-making about water and then examine some of the root causes—or “drivers”—and ecological stressors that underlie many of the symptoms we see in the form of pollution or ecosystem degradation in Wisconsin. This is followed by a summary of current water issues, many of which had been identified in the 2003 report and remain relevant today. We examine progress since 2003 but also setbacks, and discuss issues that we are likely to continue to face in the coming decades, including controlling agricultural runoff, mitigating climate change and grappling with its effects on the state’s waters, protecting groundwater from bacterial contamination and other pollutants, and preventing groundwater depletion. We also attempt to anticipate issues on the horizon. We offer a deeper look at some particular challenges, such as phosphorus pollution and groundwater contamination. We then consider the current decision-making framework and how it is shaping our capacity to respond to water challenges in Wisconsin. Finally, we offer recommendations and identify opportunities to safeguard Wisconsin’s waters in the decades ahead. From its inception, the Wisconsin Academy’s Waters of Wisconsin Initiative has brought together a diverse community of experts from across the state and from varied fields and areas of interest, to address challenges and seize opportunities related to our precious waters. We have done so as a matter of both principle and practical reality: the state of our waters reflects the ways we interact not only with them, but also with one another and our institutions. The WOW Initiative has aimed to provide guidance for Wisconsin citizens in sustaining the health of our aquatic ecosystems and the resilience of our water supplies over the long term.

Report↗
USGS2025

Streamflow regime characterization in the changing boreal ecosystem: Wildfire impacts from stream-to-regional scales

The boreal ecosystem has experienced significant changes over recent decades as wildfires become more frequent, intense, and severe. As streams are highly prevalent and ecologically relevant, understanding interactions among wildfire and hydrologic patterns is important for effective aquatic ecosystem management. This study used a Bayesian mixture model to classify streamflow regimes from modeled streamflow data for 32,730 stream reaches (totaling 295,880 km) across the Yukon and Kuskokwim basins and the Northwestern Boreal Ecosystem in Alaska, USA, and Yukon Territory, Canada. We assessed time since burn and calculated the total length of stream (km) within burn perimeters for each streamflow class from 1985 to 2015. Additionally, we used field observations (2018–2022) to compare streamflow regimes in four burned and four unburned headwater streams (drainage basins ≤150 km 2 ) in interior Alaska. Modeled stream reaches were grouped into twenty-two classes and reduced to eleven metaclasses based on similarities in streamflow statistics. These metaclasses formed two broad groups: 1) large rivers with lower variability and strong seasonal signals, and 2) mid- to small-sized tributaries with high variability, frequent high flow events, and weaker seasonal signals. The stream length burned analysis indicated an average increase of 47 km per year with first- and second-order streams experiencing more frequent fire. Empirical streamflow metrics from headwater stream gages revealed additional differences in streamflow patterns between burned and unburned streams. This streamflow classification establishes a baseline for understanding boreal stream responses to wildfire, detecting climate-induced regime shifts, and facilitating management and conservation of important boreal aquatic species.

Alaska↗
USGS1983

Complexation of copper by aquatic humic substances from different environments

The copper-complexing properties of aquatic humic substances isolated from eighteen different environments were characterized by potentiometric titration, using a cupric ion selective electrode. Potentiometric data were analyzed using FITEQL, a computer program for the determination of chemical equilibrium constants from experimental data. All the aquatic humic substances could be modelled as having two types of Cu(II)-binding sites: one with K equal to about 10 6 and a concentration of 1.0 ± 0.4 × 10 −6 M(mg C) −1 and another with K equal to about 10 8 and a concentration of 2.6 ± 1.6 × 10 −7 M(mg C) −1 . A method is described for estimating the Cu(II)-binding sites associated with dissolved humic substances in natural water based on a measurement of dissolved organic carbon, which may be helpful in evaluating chemical processes controlling speciation of Cu and bioavailability of Cu to aquatic organisms.

Science of the Total Environment↗
USGS2003

Quantitative PCR analysis of CYP1A induction in Atlantic salmon (Salmo salar)

Environmental pollutants are hypothesized to be one of the causes of recent declines in wild populations of Atlantic salmon (Salmo salar) across Eastern Canada and the United States. Some of these pollutants, such as polychlorinated biphenyls and dioxins, are known to induce expression of the CYP1A subfamily of genes. We applied a highly sensitive technique, quantitative reverse transcription-polymerase chain reaction (RT-PCR), for measuring the levels of CYP1A induction in Atlantic salmon. This assay was used to detect patterns of CYP1A mRNA levels, a direct measure of CYP1A expression, in Atlantic salmon exposed to pollutants under both laboratory and field conditions. Two groups of salmon were acclimated to 11 and 17??C, respectively. Each subject then received an intraperitoneal injection (50 mg kg-1) of either ??-naphthoflavone (BNF) in corn oil (10 mg BNF ml-1 corn oil) or corn oil alone. After 48 h, salmon gill, kidney, liver, and brain were collected for RNA isolation and analysis. All tissues showed induction of CYP1A by BNF. The highest base level of CYP1A expression (2.56??1010 molecules/??g RNA) was found in gill tissue. Kidney had the highest mean induction at five orders of magnitude while gill tissue showed the lowest mean induction at two orders of magnitude. The quantitative RT-PCR was also applied to salmon sampled from two streams in Massachusetts, USA. Salmon liver and gill tissue sampled from Millers River (South Royalston, Worcester County), known to contain polychlorinated biphenyls (PCBs), showed on average a two orders of magnitude induction over those collected from a stream with no known contamination (Fourmile Brook, Northfield, Franklin County). Overall, the data show CYP1A exists and is inducible in Atlantic salmon gill, brain, kidney, and liver tissue. In addition, the results obtained demonstrate that quantitative PCR analysis of CYP1A expression is useful in studying ecotoxicity in populations of Atlantic salmon in the wild. ?? 2003 Elsevier Science B.V. All rights reserved.

Aquatic Toxicology↗
USGS2005

Trends in hydrophobic organic contaminants in urban and reference lake sediments across the United States, 1970-2001

A shift in national policy toward stronger environmental protection began in the United States in about 1970. Conversely, urban land use, population, energy consumption, and vehicle use have increased greatly since then. To assess the effects of these changes on water quality, the U.S. Geological Survey used sediment cores to reconstruct water-quality histories for38 urban and reference lakes across the United States. Cores were age-dated, and concentration profiles of polycyclic aromatic hydrocarbons (PAHs) and chlorinated hydrocarbons were tested statistically. Significant trends in total DDT, p,p???-DDE, and total PCBs were all downward. Trends in chlordane were split evenly between upward and downward, and trends in PAHs were mostly upward. Significant trends did not occur in about one-half of cases tested. Concentrations of p,p???-DDE, p,p???-DDD, and PCBs were about one-half as likely to exceed the probable effect concentration (PEC), a sediment quality guideline, in sediments deposited in the 1990s as in 1965-1975, whereas PAHs were twice as likely to exceed the PEC in the more recently deposited sediments. Concentrations of all contaminants evaluated correlated strongly with urban land use. Upward trends in PAH concentrations, the strong association of PAH with urban settings, and rapid urbanization occurring in the United States suggest that PAHs could surpass chlorinated hydrocarbons in the threat they pose to aquatic biota in urban streams and lakes.

Environmental Science & Technology↗
USGS2012

Dissolved organic matter enhances microbial mercury methylation under sulfidic conditions

Dissolved organic matter (DOM) is generally thought to lower metal bioavailability in aquatic systems due to the formation of metal–DOM complexes that reduce free metal ion concentrations. However, this model may not be pertinent for metal nanoparticles, which are now understood to be ubiquitous, sometimes dominant, metal species in the environment. The influence of DOM on Hg bioavailability to microorganisms was examined under conditions (0.5–5.0 nM Hg and 2–10 μM sulfide) that favor the formation of β-HgS(s) (metacinnabar) nanoparticles. We used the methylation of stable-isotope enriched 201 HgCl 2 by Desulfovibrio desulfuricans ND132 in short-term washed cell assays as a sensitive, environmentally significant proxy for Hg uptake. Suwannee River humic acid (SRHA) and Williams Lake hydrophobic acid (WLHPoA) substantially enhanced (2- to 38-fold) the bioavailability of Hg to ND132 over a wide range of Hg/DOM ratios (9.4 pmol/mg DOM to 9.4 nmol/mg DOM), including environmentally relevant ratios. Methylmercury (MeHg) production by ND132 increased linearly with either SRHA or WLHPoA concentration, but SRHA, a terrestrially derived DOM, was far more effective at enhancing Hg-methylation than WLHPoA, an aquatic DOM dominated by autochthonous sources. No DOM-dependent enhancement in Hg methylation was observed in Hg–DOM–sulfide solutions amended with sufficient l -cysteine to prevent β-HgS(s) formation. We hypothesize that small HgS particles, stabilized against aggregation by DOM, are bioavailable to Hg-methylating bacteria. Our laboratory experiments provide a mechanism for the positive correlations between DOC and MeHg production observed in many aquatic sediments and wetland soils.

Environmental Science & Technology↗
USGS2019

Applying the ecology of aquatic–terrestrial linkages to freshwater and riparian management

Global stressors such as climate change, invasive species, urbanization, agricultural practices, and pollution can alter aquatic resource subsidies to terrestrial consumers. The effects of these stressors on timing, quality, and quantity of aquatic subsidies, such as adult aquatic insects, to birds, herpetofauna, and mammals, have large implications for wildlife management (Baxter et al. 2004 , Saunders and Fausch 2007 , Walters et al. 2008 , Sullivan and Rodewald 2012 , Morrissey et al. 2015 , Kraus et al. 2016 , Larsen et al. 2016 , Sullivan et al. 2019 ). For example, insect-mediated contaminant transport from polluted rivers expose song bird nestlings and other protected birds to potentially toxic levels of persistent organic contaminants and pharmaceuticals (Walters et al. 2010 , Richmond et al. 2018 ). Recent declines in aquatic insect production caused by pollution and changes in land use have been tied to global declines in terrestrial insectivores such as birds and bats (Hallmann et al. 2014 , Morrissey et al. 2015 , Raby et al. 2018 ). These natural-resource impacts from aquatic–terrestrial exposure and loss of resource subsidies are leading to changes in monitoring protocols and how management agencies evaluate the effectiveness of corrective remedies (Muehlbauer et al. 2019 ). For researchers interested in the application of resource subsidy research, a logical next step is to help practitioners anticipate effects of global stressors on aquatic-terrestrial linkages and incorporate these principles into decision making.

Freshwater Science↗
USGS2020

Macroinvertebrate oviposition habitat selectivity and egg-mass desiccation tolerances: Implications for population dynamics in large regulated rivers

Aquatic insects exhibit complex life cycles that include egg, larval, adult, and, in some instances, pupal stages. Disturbances at any of these life stages can affect overall population dynamics. Yet, efforts to understand the effects of disturbances, such as hydrologic alterations, overwhelmingly focus on the larval life stage of aquatic insects. We evaluated the potential for load-following flows associated with hydroelectric power production to act as a population bottleneck for aquatic insects via reductions in the availability and temporal persistence of optimal oviposition habitats. Specifically, we quantified the oviposition habitat selectivity of Baetis spp. (Baetidae), Brachycentrus occidentalis (Brachycentridae), Chironomidae (Diptera), and Hydropsyche occidentalis (Hydropsychidae) downstream of Flaming Gorge Dam, Utah, USA. We found that all taxa except H. occidentalis preferentially laid eggs on large emergent substrates located along the river edge. Peak discharge associated with load-following flows substantially reduced the number of emergent substrates available for oviposition, and daily low flows exposed eggs in these habitats to desiccation and drying. When subjected to experimental drying, both Baetis and H. occidentalis eggs experienced nearly 100% mortality after 2 h, whereas most B. occidentalis remained viable after 8 h. Our paired field and experimental results are consistent with the hypothesis that load-following flows from hydroelectric dams produce a population bottleneck for aquatic insects by short circuiting recruitment processes. Environmental flows that seek to improve the health of tailwater aquatic insect populations would benefit from consideration of habitat requirements for all life stages of aquatic insects.

Utah↗
USGS2003

Water-quality, bed-sediment, and biological data, for streams in the upper Prickly Pear Creek watershed, Montana, 2001

The upper Prickly Pear Creek watershed encompasses the upstream 15 miles of Prickly Pear Creek, south of Helena, Montana (fig. 1). The headwaters of Prickly Pear Creek and its tributaries (Beavertown Creek, Clancy Creek, Dutchman Creek, Golconda Creek, Lump Gulch, Spring Creek, and Warm Springs Creek) are primarily in the Helena National Forest, whereas the central part of the watershed primarily is within either Bureau of Land Management (BLM) or privately owned property. Three mining districts are present in the upper Prickly Pear Creek watershed: Alhambra, Clancy, and Colorado. Numerous prospects, adits, tailings piles, mills, dredge piles, and mines (mostly inactive) are located throughout the watershed. These districts contain polymetallic (Ag, Au, Cu, Pb, Zn) vein deposits and precious-metal (Au-Ag) vein and disseminated deposits that were exploited beginning in the 1860’s. Placer Au deposits in the major streams were extensively mined in the late 1800’s and early 1900’s. As part of a cooperative effort with Federal land management agencies, the U.S. Geological Survey (USGS) is currently using an integrated approach to investigate two mining impacted watersheds in the western United States (the Animas River in Colorado and the Boulder River in Montana). These studies provide the USDA Forest Service and BLM scientific data for implementing informed land-management decisions regarding cleanup of abandoned mine lands within each watershed. A similar integrated-science approach will be used to characterize the upper Prickly Pear Creek watershed with respect to water and streambed sediment chemistry, aquatic biota, and geologic framework. This integrated database presents data that will be used to identify important pathways of metals movement and biological impacts, thereby guiding resource management decisions of land-managers in several publications that are in preparation. Watershed-level characterization in terms of water quality, streambed sediment chemistry, and fish health will facilitate determinations of whether removal of contaminated materials or other cleanup activities are necessary, planning of short- and long-term restoration efforts, and development of a monitoring plan to document cleanup effectiveness.

Montana↗
USGS2020

Upper Mississippi River system weighted wind fetch analysis (1989, 2000, 2010/2011)

Wind fetch is defined as the unobstructed distance that wind can travel over water in a constant direction. Fetches are limited by landforms surrounding the body of water. Fetch is an important characteristic of open water because longer fetches can result in larger wind-generated waves. The larger waves, in turn, can increase shoreline erosion and sediment resuspension (Rohweder and others 2012). Increases in sediment resuspension lead to increases in water turbidity, which in turn decreases light penetration and, therefore, create conditions less conducive to aquatic plant growth (Giblin and others 2010). A wind fetch model was developed by David Finlayson, U. S. Geological Survey, Pacific Science Center, while he was a Ph.D. student at the University of Washington (Finlayson 2005). This method calculates effective fetch using the recommended procedure of the Shore Protection Manual (USACE 1984). Scientists at the United States Geological Survey, Upper Midwest Environmental Sciences Center (UMESC) and the United States Army Corps of Engineers (USACE) further refined this model (Rohweder and others 2012) and structured it to operate using the most recent version of the ArcMap Geographic Information System platform (Esri, 2019). At the time the analysis was performed, the version of ArcMap used was 10.7.1. The model refined in 2012 was used for the analyses described in this report. Using this model, UMESC performed an analysis to model weighted wind fetch for the Upper Mississippi River System (UMRS) corresponding to three separate time periods of land cover spatial data acquisition (1989, 2000, and 2010/2011). The purpose of the analysis was to examine how fetch varies over time and space within the UMRS for potential management applications. For more detailed information on the wind fetch model, examine the USGS Open-File Report by Rohweder and others (2012).

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗
USGS2021

Pesticides in US Rivers: Regional differences in use, occurrence, and environmental toxicity, 2013 to 2017

Pesticides pose a threat to the environment, but because of the substantial number of compounds, a comprehensive assessment of pesticides and an evaluation of the risk that they pose to human and aquatic life is challenging. In this study, improved analytical methods were used to quantify 221 pesticide concentrations in surface waters over the time period from 2013 to 2017. Samples were collected from 74 river sites in the conterminous US (CONUS). Potential toxicity was assessed by comparing surface water pesticide concentrations to standard concentrations that are considered to have adverse effects on human health or aquatic organisms. The majority of pesticide use is related to agriculture, and agricultural production varies across the CONUS. Therefore, our results were summarized by region (Northeast, South, Midwest, West and Pacific), with the expectation that crop production differences would drive variability in pesticide use, detection frequency, and benchmark exceedance patterns. Although agricultural pesticide use was at least 2.5 times higher in the Midwest (49 kg km −2 ) than in any of the other four regions (Northeast, South, West, and Pacific, 3 to 21 kg km −2 ) and the average number of pesticides detected in the Midwest was at least 1.5 higher ( n = 25) than the other four regions ( n = 8 to n = 16), the potential toxicity results were more evenly distributed. At least 50% of the sites within each of the 5 regions had at least 1 chronic benchmark exceedance. Imidacloprid posed the greatest potential threat to aquatic life with a total of 245 benchmark exceedances at 60 of the 74 sites. These results show that pesticides persist in the environment beyond the site of application and expected period of use. Continued monitoring and research are needed to improve our understanding of pesticide effects on aquatic and human life.

Science of the Total Environment↗
USGS1999

Modelling removal mechanisms of Pb, Cu, Zn and Cd in acidic groundwater during the neutralization by ambient surface and ground waters

Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal removal is a strong function of the physical system. Relative to direct discharge of ARD into streams, lower metal removals are observed where ARD enters streamwaters during the latter stages of neutralization by ambient groundwater after most of the Fe has precipitated and been retained in the soils. The mixing experiments, which represent the field simulations, also demonstrated the importance of dissolved metal to particle Fe ratios in controlling dissolved metal removal along the chemical pathway. Finally, model calculations indicate that hydrous Fe oxides and particulate organic carbon are more important than hydrous Al oxides in removing metals and that both inorganic and organic complexation must be considered when modeling metal removal from aquatic systems that are impacted by sulfide oxidation.

Environmental Science & Technology↗
USGS2002

Meeting ecological and societal needs for freshwater

Human society has used freshwater from rivers, lakes, groundwater, and wetlands for many different urban, agricultural, and industrial activities, but in doing so has overlooked its value in supporting ecosystems. Freshwater is vital to human life and societal well-being, and thus its utilization for consumption, irrigation, and transport has long taken precedence over other commodities and services provided by freshwater ecosystems. However, there is growing recognition that functionally intact and biologically complex aquatic ecosystems provide many economically valuable services and long-term benefits to society. The short-term benefits include ecosystem goods and services, such as food supply, flood control, purification of human and industrial wastes, and habitat for plant and animal life—and these are costly, if not impossible, to replace. Long-term benefits include the sustained provision of those goods and services, as well as the adaptive capacity of aquatic ecosystems to respond to future environmental alterations, such as climate change. Thus, maintenance of the processes and properties that support freshwater ecosystem integrity should be included in debates over sustainable water resource allocation. The purpose of this report is to explain how the integrity of freshwater ecosystems depends upon adequate quantity, quality, timing, and temporal variability of water flow. Defining these requirements in a comprehensive but general manner provides a better foundation for their inclusion in current and future debates about allocation of water resources. In this way the needs of freshwater ecosystems can be legitimately recognized and addressed. We also recommend ways in which freshwater ecosystems can be protected, maintained, and restored. Freshwater ecosystem structure and function are tightly linked to the watershed or catchment of which they are a part. Because riverine networks, lakes, wetlands, and their connecting groundwaters, are literally the “sinks” into which landscapes drain, they are greatly influenced by terrestrial processes, including many human uses or modifications of land and water. Freshwater ecosystems, whether lakes, wetlands, or rivers, have specific requirements in terms of quantity, quality, and seasonality of their water supplies. Sustainability normally requires these systems to fluctuate within a natural range of variation. Flow regime, sediment and organic matter inputs, thermal and light characteristics, chemical and nutrient characteristics, and biotic assemblages are fundamental defining attributes of freshwater ecosystems. These attributes impart relatively unique characteristics of productivity and biodiversity to each ecosystem. The natural range of variation in each of these attributes is critical to maintaining the integrity and dynamic potential of aquatic ecosystems; therefore, management should allow for dynamic change. Piecemeal approaches cannot solve the problems confronting freshwater ecosystems. Scientific definitions of the requirements to protect and maintain aquatic ecosystems are necessary but insufficient for establishing the appropriate distribution between societal and ecosystem water needs. For scientific knowledge to be implemented science must be connected to a political agenda for sustainable development. We offer these recommendations as a beginning to redress how water is viewed and managed in the United States: (1) Frame national and regional water management policies to explicitly incorporate freshwater ecosystem needs, particularly those related to naturally variable flow regimes and to the linking of water quality with water quantity; (2) Define water resources to include watersheds, so that freshwaters are viewed within a landscape, or systems context; (3) Increase communication and education across disciplines, especially among engineers, hydrologists, economists, and ecologists to facilitate an integrated view of freshwater resources; (4) Increase restoration efforts, using well-grounded ecological principles as guidelines; (5) Maintain and protect the remaining freshwater ecosystems that have high integrity; and (6) Recognize the dependence of human society on naturally functioning ecosystems.

Ecological Applications↗
USGS2007

Hydrogeologic Setting and Ground-Water Flow in the Leetown Area, West Virginia

The Leetown Science Center is a research facility operated by the U.S. Geological Survey that occupies approximately 455-acres near Kearneysville, Jefferson County, West Virginia. Aquatic and fish research conducted at the Center requires adequate supplies of high-quality, cold ground water. Three large springs and three production wells currently (in 2006) supply water to the Center. The recent construction of a second research facility (National Center for Cool and Cold Water Aquaculture) operated by the U.S. Department of Agriculture and co-located on Center property has placed additional demands on available water resources in the area. A three-dimensional steady-state finite-difference ground-water flow model was developed to simulate ground-water flow in the Leetown area and was used to assess the availability of ground water to sustain current and anticipated future demands. The model also was developed to test a conceptual model of ground-water flow in the complex karst aquifer system in the Leetown area. Due to the complexity of the karst aquifer system, a multidisciplinary research study was required to define the hydrogeologic setting. Geologic mapping, surface- and borehole-geophysical surveys, stream base-flow surveys, and aquifer tests were conducted to provide the hydrogeologic data necessary to develop and calibrate the model. It would not have been possible to develop a numerical model of the study area without the intensive data collection and methods developments components of the larger, more comprehensive hydrogeologic investigation. Results of geologic mapping and surface-geophysical surveys verified the presence of several prominent thrust faults and identified additional faults and other complex geologic structures (including overturned anticlines and synclines) in the area. These geologic structures are known to control ground-water flow in the region. Results of this study indicate that cross-strike faults and fracture zones are major avenues of ground-water flow. Prior to this investigation, the conceptual model of ground-water flow for the region focused primarily on bedding planes and strike-parallel faults and joints as controls on ground-water flow but did not recognize the importance of cross-strike faults and fracture zones that allow ground water to flow downgradient across or through less permeable geologic formations. Results of the ground-water flow simulation indicate that current operations at the Center do not substantially affect either streamflow (less than a 5-percent reduction in annual streamflow) or ground-water levels in the Leetown area under normal climatic conditions but potentially could have greater effects on streamflow during long-term drought (reduction in streamflow of approximately 14 percent). On the basis of simulation results, ground-water withdrawals based on the anticipated need for an additional 150 to 200 gal/min (gallons per minute) of water at the Center also would not seriously affect streamflow (less than 8 to 9 percent reduction in streamflow) or ground-water levels in the area during normal climatic conditions. During drought conditions, however, the effects of current ground-water withdrawals and anticipated additional withdrawals of 150 to 200 gal/min to augment existing supplies result in moderate to substantial declines in water levels of 0.5-1.2 feet (ft) in the vicinity of the Center's springs and production wells. Streamflow was predicted to be reduced locally by approximately 21 percent. Such withdrawals during a drought or prolonged period of below normal ground-water levels would result in substantial declines in the flow of the Center's springs and likely would not be sustainable for more than a few months. The drought simulated in this model was roughly equivalent to the more than 1-year drought that affected the region from November 1998 through February 2000. The potential reduction in streamflow is a result of capture of ground water tha

Scientific Investigations Report↗
USGS2016

Science center capabilities to monitor and investigate Michigan’s water resources, 2016

Michigan faces many challenges related to water resources, including flooding, drought, water-quality degradation and impairment, varying water availability, watershed-management issues, stormwater management, aquatic-ecosystem impairment, and invasive species. Michigan’s water resources include approximately 36,000 miles of streams, over 11,000 inland lakes, 3,000 miles of shoreline along the Great Lakes (MDEQ, 2016), and groundwater aquifers throughout the State. The U.S. Geological Survey (USGS) works in cooperation with local, State, and other Federal agencies, as well as tribes and universities, to provide scientific information used to manage the water resources of Michigan. To effectively assess water resources, the USGS uses standardized methods to operate streamgages, water-quality stations, and groundwater stations. The USGS also monitors water quality in lakes and reservoirs, makes periodic measurements along rivers and streams, and maintains all monitoring data in a national, quality-assured, hydrologic database. The USGS in Michigan investigates the occurrence, distribution, quantity, movement, and chemical and biological quality of surface water and groundwater statewide. Water-resource monitoring and scientific investigations are conducted statewide by USGS hydrologists, hydrologic technicians, biologists, and microbiologists who have expertise in data collection as well as various scientific specialties. A support staff consisting of computer-operations and administrative personnel provides the USGS the functionality to move science forward. Funding for USGS activities in Michigan comes from local and State agencies, other Federal agencies, direct Federal appropriations, and through the USGS Cooperative Matching Funds, which allows the USGS to partially match funding provided by local and State partners. This fact sheet provides an overview of the USGS current (2016) capabilities to monitor and study Michigan’s vast water resources. More information regarding projects by the Michigan Water Science Center (MI WSC) is available at http://mi.water.usgs.gov/ .

Michigan↗
USGS2009

Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions

The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons. ?? Springer Science+Business Media B.V. 2009.

Aquatic Ecology↗
USGS2007

Local structuring factors of invertebrate communities in ephemeral freshwater rock pools and the influence of more permanent water bodies in the region

We used three isolated clusters of small ephemeral rock pools on a sandstone flat in Utah to test the importance of local structuring processes on aquatic invertebrate communities. In the three clusters we characterized all ephemeral rock pools (total: 27) for their morphometry, and monitored their water quality, hydrology and community assemblage during a full hydrocycle. In each cluster we also sampled a set of more permanent interconnected freshwater systems positioned in a wash, draining the water from each cluster of rock pools. This design allowed additional testing for the potential role of more permanent water bodies in the region as source populations for the active dispersers and the effect on the community structure in the rock pools. Species richness and community composition in the rock pools correlated with level of permanence and the ammonia concentration. The length of the rock pool inundation cycle shaped community structure, most probably by inhibiting colonization by some taxa (e.g. tadpoles and insect larvae) through developmental constraints. The gradient in ammonia concentrations probably reflects differences in primary production. The more permanent water bodies in each wash differed both environmentally and in community composition from the connected set of rock pools. A limited set of active dispersers was observed in the rock pools. Our findings indicate that aquatic invertebrate communities in the ephemeral rock pools are mainly structured through habitat permanence, possibly linked with biotic interactions and primary production. ?? 2007 Springer Science+Business Media B.V.

Hydrobiologia↗
USGS2021

Variation in metal concentrations across a large contamination gradient is reflected in stream but not linked riparian food webs

Aquatic insects link food web dynamics across freshwater-terrestrial boundaries and subsidize terrestrial consumer populations. Contaminants that accumulate in larval aquatic insects and are retained across metamorphosis can increase dietary exposure for riparian insectivores. To better understand potential exposure of terrestrial insectivores to aquatically-derived trace metals, metal concentrations in water and tissues were analyzed from different components of streams and riparian food webs across a large (2–3 orders of magnitude) metal gradient (e.g., Zn, Cu, Cd, Pb) in the Rocky Mountains (USA). Our research indicates that the trace metal concentration gradient present among streams was lost during metamorphosis of aquatic larval insects into terrestrially flying adults, decoupling terrestrial exposures from aquatic concentrations. This pattern was caused by declines in 1) among-stream variation in trace metal concentrations, 2) relationships between metal concentrations in paired water and food web components, and 3) mean metal concentrations within aquatic food webs and across the aquatic-terrestrial boundary. Specifically, among-stream variation in trace metal concentrations was highest for water and aquatic vegetation, intermediate for aquatic insect larvae (~30% lower than water) and lowest for adult aquatic insects and riparian spiders (~65% lower). Metal concentrations in paired water and food web components ranged from highly related across the stream-metal gradient (slopes ~1) for water and aquatic vegetation, to less related (slopes closer to 0) for aquatic vegetation and aquatic insect larvae, to unrelated (slopes ~0) for aquatic larval and adult insects. Finally, mean metal concentrations were highest in aquatic vegetation and lowest in adult aquatic insects emerging from streams (~50% lower than aquatic vegetation). Our results indicate less efficient trophic transfer and higher metamorphic loss of trace metals from high metal streams (i.e., exposure-dependent transfer). For many trace metals, aquatic-terrestrial dietary transfer is unlikely to be an important source of exposure for terrestrial insectivores of adult aquatic insects.

Science of the Total Environment↗