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Conservation Act of 1980 (ANILCA, 1980) requires the Secretary of Interior to conduct a continuing study of fish, wildlife, and habitats on the Innoko National Wildlife Refuge (INWR). Included in this study is a determination of the extent, location, and carrying capacity of fish and wildlife habitats.
Because of the considerable wildlife benefits offered by the Quivira National Wildlife Refuge in south-central Kansas, there is a desire to ensure suitable water quality. To assess the quality of water flowing from Rattlesnake Creek into the refuge, the U.S. Geological Survey collected periodic water samples from December 1998 through June 2001 and analyzed the samples for physical properties, dissolved solids, total suspended solids, suspended sediment, major ions, nutrients, metals, pesticides, and indicator bacteria. Concentrations of 10 of the 125 chemicals analyzed did not meet water-quality criteria to protect aquatic life and drinking water in a least one sample. These were pH, turbidity, dissolved oxygen, dissolved solids, sodium, chloride, phosphorus, total coliform bacteria, E. coli bacteria, and fecal coliform bacteria. No metal or pesticide concentrations exceeded water-quality criteria. Twenty-two of the 43 metals analyzed were not detected, and 36 of the 46 pesticides analyzed were not detected. Because dissolved solids, sodium, chloride, fecal coliform bacteria, and other chemicals that are a concern for the health and habitat of fish and wildlife at the refuge cannot be measured continuously, regression equations were developed from a comparison of the analytical results of periodic samples and in-stream monitor measurements of specific conductance, pH, water temperature, turbidity, and dissolved oxygen. A continuous record of estimated chemical concentrations was developed from continuously recorded in-stream measurements. Annual variation in water quality was evaluated by comparing 1999 and 2000 sample data- the 2 years for which complete data sets were available. Median concentrations of alkalinity, fluoride, nitrate, and fecal coliform bacteria were smaller or did not change from 1999 to 2000. Dissolved solids, total suspended solids, sodium, chloride, sulfate, total organic nitrogen, and total phosphorus had increases in median concentrations from 1999 to 2000. Increases in the median concentrations of the major ions were expected due to decreased rainfall in 2000 and very low streamflow late in the year. Increases for solids and nutrients may have been due to the unusually high streamflow in the early spring of 2000. This was the time of year when fields were tilled, exposing solids and nutrients that were transported with runoff to Rattlesnake Creek. Load estimates indicate the chemical mass transported into the refuge and can be used in the development of total maximum daily loads (as specified by the U.S. Environmental Protection Agency) for water-quality contaminants in Rattlesnake Creek. Load estimates also were used to evaluate seasonal variation in water quality. Seasonal variation was most pronounced in the estimates of nutrient loads, and most of the nutrient load transported to the refuge occurred during just a few periods of surface runoff in the spring and summer. This information may be used by resource managers to determine when water-diversion strategies would be most beneficial. Load estimates also were used to calculate yields, which are useful for site comparisons. The continuous and real-time nature of the record of estimated concentrations, loads, and yields may be important for resource managers, recreationalists, or others for evaluating water-diversion strategies, making water-use decisions, or assessing the environmental effects of chemicals in time to prevent adverse effects on fish or other aquatic life at the refuge.
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Bats are diverse and abundant in many ecosystems worldwide. They perform important ecosystem functions, particularly by consuming large quantities of insects (Cleveland and others, 2006; Jones and others, 2009; Kuhn and others, 2011). The importance of bats to biodiversity and to ecosystem integrity has been overlooked in many regions, largely because the challenges of detecting and studying these small, nocturnal mammals have rendered a paucity of information on matters as basic as species distribution and natural history attributes. Recently, concern for bats has arisen in response to recognition of large-scale threats, such as white-nosed syndrome (WNS; Turner and others, 2009; Frick and others, 2010) and mortality at wind energy facilities (Arnett and others, 2008), factors that are causing unprecedented population declines of bats (Boyles and others, 2011). WNS is a fungal disease that has killed more than 1 million cave-hibernating bats in eastern North America since being discovered in New York State in 2006 (U.S. Fish and Wildlife Service, 2012). WNS has spread rapidly from northeastern U.S., and as of August 2012 has been confirmed as far west as eastern Missouri(U.S. Fish and Wildlife Service, 2013). Given the rapid spread of WNS, there is concern that the disease may soon affect western bat populations. Hibernating bats are particularly vulnerable to the effects of WNS (Blehert and others, 2009). Refuges in eastern Washington, including the Mid-Columbia River National Wildlife Refuge Complex (MCRNWRC) and Little Pend Oreille National Wildlife Refuge, support many potential hibernacula. Sixteen species of bats potentially occur on these refuges, including one federally listed species of concern (Townsend’s big-eared bat [Corynorhinus townsendii]; see table 1 for scientific names of bats), and 12 species that are of conservation concern in Washington and Oregon (table 1). However, little is known about bats on these refuges because few surveys have been done, and none have been done during winter. Refuge biologists are lacking even the most basic information, such as species presence, and location and status of hibernacula. In order to assess vulnerability and develop a strategy for management of WNS, refuge managers need to know where bats are hibernating, and which species are using each hibernaculum. The goal of this project was to provide information on the status of wintering bats to refuge biologists and managers in order to support decision-making that might minimize the threat of WNS in western bat populations. We conducted surveys of bat activity in winter and early spring as an initial step toward identifying bat species that may be over-wintering and locating potential hibernacula on these refuges. Our specific objectives were to identify bat species using the refuges, to identify areas of resident bat activity in autumn, winter, and early spring using acoustic bat detectors, and to try new methods for quick surveys of bat activity.
We summarized the cause of death for 2,980 bald eagles ( Haliaeetus leucocephalus ) and 1,427 golden eagles ( Aquila chrysaetos ) submitted to the National Wildlife Health Center in Madison, Wisconsin, USA, for diagnosis between 1975 and the beginning of 2013. We compared the proportion of eagles with a primary diagnosis as electrocuted, emaciated, traumatized, shot or trapped, diseased, poisoned, other, and undetermined among the 4 migratory bird flyways of the United States (Atlantic, Mississippi, Central, and Pacific). Additionally, we compared the proportion of lead-poisoned bald eagles submitted before and after the autumn 1991 ban on lead shot for waterfowl hunting. Trauma and poisonings (including lead poisoning) were the leading causes of death for bald eagles throughout the study period, and a greater proportion of bald eagles versus golden eagles were diagnosed as poisoned. For golden eagles, the major causes of mortality were trauma and electrocution. The proportion of lead poisoning diagnoses for bald eagles submitted to the National Wildlife Health Center displayed a statistically significant increase in all flyways after the autumn 1991 ban on the use of lead shot for waterfowl hunting. Thus, lead poisoning was a significant cause of mortality in our necropsied eagles, suggesting a continued need to evaluate the trade-offs of lead ammunition for use on game other than waterfowl versus the impacts of lead on wildlife populations. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Summary This report summarizes a Wildlife Disease Association sponsored workshop held in 2016. The overall objective of the workshop was to use available evidence and selected subject matter expertise to define the essential functions of a National Wildlife Health Program and the resources needed to deliver a robust and reliable program, including the basic infrastructure, workforce, data and information systems, governance, organizational capacity, and essential features, such as wildlife disease surveillance, diagnostic services, and epidemiological investigation. This workshop also provided the means to begin the process of defining the essential attributes of a national wildlife health program that could be scalable and adaptable to each nation’s needs.
On 13 August 2004, the first of four hurricanes to strike Florida in <6 weeks came ashore near J. N. ?Ding? Darling National Wildlife Refuge (JNDDNWR) Complex, Sanibel Island, FL. Hurricane Charley passed just north of Sanibel Island with maximum sustained winds of 145 mph (123 knots) and a storm surge of 0.3-2.7 m. We surveyed storm damage to JNDDNWR Complex from 20-24 September 2004. Our goals were to assess damage to: wetlands for Mangrove Cuckoos (Coccyzus minor) and Black-whiskered Vireo (Vireo altiloquus), waterbird rookeries/mangrove islands, impoundments, sea grass beds, and hardwood hammocks. The refuge complex sustained moderate to catastrophic damage to vegetation, especially mangrove forests and waterbird nesting or roosting islands. Lumpkin Island, Hemp Island, and Bird Key waterbird nesting areas had >50% and sometimes 90% of their vegetation severely damaged (dead, broken tree stems, and tipped trees). Shell Mound Trail of JNDDNWR sustained catastrophic damage to its old growth mangrove forests. Direct storm mortality and injury to manatees in the area was probably slight. Because seagrass beads and manatee habitat extend beyond refuge boundaries, we recommended a regional approach with partner agencies to more thoroughly assess storm impacts and monitor recovery of seagrass and manatees. Besides intensive monitoring of waterbirds and their nesting habitat (pre- and post-storm), we recommend that the Mangrove Cuckoo be used as an indicator species for recovery of mangrove forests and also for monitoring songbirds at risk. Black-whiskered Vireo may be another potential indicator species to monitor in mangrove forests. Damaged vegetation should be monitored for recovery (permanent or long-term plots), especially where previous study plots have been established and with additional plots in mangrove forests of waterbird nesting islands and freshwater wetlands. Potential loss of wetlands may be prevented by water level monitoring, locating the positions (GPS-GIS) and maintaining existing water control structures, creating a GIS map of refuge with accurate vertical data, and monitoring and eradicating invasive plants. Invasive species, including Brazilian pepper (Schinus terebinthifolius) and air potato (Dioscorea bulbifora), were common in a very limited survey. As an important monitoring goal, we recommend that species presence-absence data analysis (with probability of detection) be used to determine changes in animal communities. This could be accomplished possibly with comparison to other storm-damaged and undamaged refuges in the Region. This information may be helpful to refuge managers when storms return in the future.
• On 13 August 2004, the first of four hurricanes to strike Florida in <6 weeks came ashore near J. N. “Ding” Darling National Wildlife Refuge (JNDDNWR) Complex, Sanibel Island, Florida. The eye of Category 4 Hurricane Charley passed just north of Sanibel Island with maximum sustained winds of 145 mph (123 knots) and a storm surge of 0.3-2.7 m (1-9 ft). Three USGS-BRD scientists (coastal ecologist and research wildlife biologists) and a USFWS wildlife biologist surveyed the storm damage to JNDDNWR Complex on the ground from 20-24 September 2004. • At the request of United States Fish and Wildlife Service refuge staff, the USGS team concentrated on assessing damage to wetlands and habitat for selected bird populations (especially mangrove forests, Mangrove Cuckoos [Coccyzus minor], and Black-whiskered Vireo [Vireo altiloquus]), waterbird rookeries (mangrove islands), impoundments (waterbirds and waterfowl), sea grass beds (manatees), and upland hardwood hammocks and ridges (threatened eastern indigo snake [Drymarchon couperi]). • The refuge complex sustained moderate to catastrophic damage to vegetation, especially mangrove forests and waterbird nesting or roosting islands. Lumpkin Island, Hemp Island, and Bird Key waterbird nesting areas had >50% and sometimes 90% of their vegetation severely damaged (dead, broken tree stems, and tipped trees). The Shell Mound Trail area of JNDDNWR sustained catastrophic damage to its old growth mangrove forests. Direct storm mortality and injury to manatees in the area of the JNDDNWR Complex was probably slight as manatees may have several strategies to reduce storm mortality. Damage to seagrass beds, an important habitat for manatees, fishes and invertebrates, is believed to be limited to the breach at North Captiva Island. At this breach, refuge staff documented inundation of beds by sand and scarring by trees dragged by winds. • Because seagrass beads and manatee habitat extend beyond refuge boundaries (see p. 28), a regional approach with partner agencies to more thoroughly assess storm impacts and monitor recovery of seagrass and manatees is recommended. • Besides intensive monitoring of waterbirds and their nesting habitat (pre- and post-storm), the survey team recommends that the Mangrove Cuckoo be used as an indicator species for recovery of mangrove forests and also for monitoring songbirds at risk (this songbird is habitat-area sensitive). Black-whiskered Vireo may be another potential indicator species to monitor in mangrove forests. Monitoring for these species can be done by distance sampling on transects or by species presenceabsence from point counts. • Damaged vegetation should be monitored for recovery (permanent or long-term plots), especially where previous study plots have been established and with additional plots in mangrove forests of waterbird nesting islands and freshwater wetlands. • Potential loss of wetlands (and information for management) may be prevented by water level monitoring (3 permanent stations), locating the positions (GPS-GIS) and maintaining existing water control structures, creating a GIS map of the refuge with accurate vertical data, and monitoring and eradicating invasive plants. Invasive species, including Brazilian pepper (Schinus terebinthifolius) and air potato (Dioscorea bulbifora), were common in a very limited survey and may become more dominant in areas damaged by the storm. Special attention is needed to eradicate these exotic plants. • As an important monitoring goal, the survey team recommends that species presence-absence data analysis (with probability of detection) be used to determine changes in animal communities. This could be accomplished possibly with comparison to other storm-damaged and undamaged refuges in the Region. This information may be helpful to refuge managers when storms return in the future.
Since its establishment in 1903, the National Wildlife Refuge System (NWRS) has grown to 635 units and 37 Wetland Management Districts in the United States and its territories. These units provide the seasonal habitats necessary for migratory waterfowl and other species to complete their annual life cycles. Habitat conversion and fragmentation, invasive species, pollution, and competition for water have stressed refuges for decades, but the interaction of climate change with these stressors presents the most recent, pervasive, and complex conservation challenge to the NWRS. Geographic isolation and small unit size compound the challenges of climate change, but a combined emphasis on species that refuges were established to conserve and on maintaining biological integrity, diversity, and environmental health provides the NWRS with substantial latitude to respond. Individual symptoms of climate change can be addressed at the refuge level, but the strategic response requires system-wide planning. A dynamic vision of the NWRS in a changing climate, an explicit national strategic plan to implement that vision, and an assessment of representation, redundancy, size, and total number of units in relation to conservation targets are the first steps toward adaptation. This adaptation must begin immediately and be built on more closely integrated research and management. Rigorous projections of possible futures are required to facilitate adaptation to change. Furthermore, the effective conservation footprint of the NWRS must be increased through land acquisition, creative partnerships, and educational programs in order for the NWRS to meet its legal mandate to maintain the biological integrity, diversity, and environmental health of the system and the species and ecosystems that it supports.
The Great Dismal Swamp (GDS) National Wildlife Refuge delivers multiple ecosystem services, including air quality and human health via fire mitigation. Our analysis estimates benefits of this service through its potential to reduce catastrophic wildfire related impacts on the health of nearby human populations. We used a combination of high-frequency satellite data, ground sensors, and air quality indices to determine periods of public exposure to dense emissions from a wildfire within the GDS. We examined emergency department (ED) visitation in seven Virginia counties during these periods, applied measures of cumulative Relative Risk to derive the effects of wildfire smoke exposure on ED visitation rates, and estimated economic losses using regional Cost of Illness values established within the US Environmental Protection Agency BenMAP framework. Our results estimated the value of one avoided catastrophic wildfire in the refuge to be \$3.69 million (2015 USD), or \$306 per hectare of burn. Reducing the frequency or severity of extensive, deep burning peatland wildfire events has additional benefits not included in this estimate, including avoided costs related to fire suppression during a burn, carbon dioxide emissions, impacts to wildlife, and negative outcomes associated with recreation and regional tourism. We suggest the societal value of the public health benefits alone provides a significant incentive for refuge mangers to implement strategies that will reduce the severity of catastrophic wildfires.
The lakebed in Wapato Lake National Wildlife Refuge (NWR) in northwestern Oregon was farmed for decades prior to the establishment of the refuge in 2013. Planning for restoration of these lands required extensive data collection and construction of a water budget and tools to design and evaluate potential restoration strategies. The U.S. Geological Survey (USGS) and U.S. Fish and Wildlife Service worked together to monitor streamflow and water levels in and around Wapato Lake NWR, apply the USGS Shoreline Management Tool (SMT), then construct and apply a water-budget-based Water Management Scenario Tool (WMST). The SMT was used to determine the spatial availability of different water depths (as potential habitat for different species) as a function of water level and other factors, based on topographic data. The WMST uses a water-budget approach to predict daily water levels, inflows, outflows, and areas of specific categories of water depth in the refuge over the course of a water year in response to a range of hydrologic and meteorological conditions and potential water-management strategies. In this study, two hypothetical water-management strategies were simulated to predict their effect on water levels and areas with specific water depths as an indicator of potential habitat. In the first scenario, several tributaries that had been diverted around the lakebed since the 1930s were reconnected to the lake, and an outflow weir was used to control lake level and to create a lake and seasonal wetlands of specific depths. In the second scenario, an outflow weir was combined with pumps to help meet target lake levels. Results showed that reconnecting the largest three tributaries to Wapato Lake would provide sufficient water to create a range of aquatic conditions in most years. For a median water year, rainfall and tributary flows in these scenarios provided 99 percent of total inputs to the lake, whereas pumping, weir outflows, and open-water evaporation accounted for 95–97 percent of losses. Management of lake levels could be accomplished with a variable-elevation outflow weir or a combination of a weir and pumps. The lake would take longer to fill to a higher seasonal target level during a dry year. Without an outflow weir or other means of allowing water to flow out of the lake, the largest of two existing pumps would need to be used during late spring or early summer to attain a lower seasonal target water level in summer. High-water conditions downstream of Wapato Lake may prevent the use of a simple outflow weir, as historical downstream water levels in winter and spring sometimes were higher than the target water levels used in these scenarios. Water-budget-based methods applied in this study have proven to be valuable for the design and evaluation of potential restoration strategies at Wapato Lake NWR.
A history is given of the Seney National Wildlife Refuge and the losses of goslings of Canada geese ( Branta canadensis ) recorded since inception of the refuge in 1935. Since 1960, when more reliable data became available, losses have been extensive every 4 years. Gosling deaths are attributed to the infection with Leucocytozoon simondi . The blackfly ( Simulium innocens ) is considered to be the prime vector in the transmission of this blood parasite to goslings.
J.N. “Ding” Darling National Wildlife Refuge (DDNWR) is located on Sanibel Island along the southwestern coast of Florida, USA. Sanibel Island is heavily developed, but DDNWR provides protection for a large mangrove area that supports biodiversity and recreational opportunity. However, nitrogen (N) and phosphorus (P) eutrophication attributed to agriculture discharge along the Caloosahatchee River has affected the area’s aquatic habitat with algal blooms and may be causing untimely degradation of Sanibel’s mangrove forests. We launched a series of studies to understand how additional nutrient loading to the levels expected in the future might affect DDNWR’s mangrove resource. We experimentally fertilized selected mangrove forest areas with N fertilizer (+N; NH4) and P fertilizer (+P; P 2 O 5 ) for three years, and monitored soil surface elevation change, soil and pneumatophore CO 2 fluxes from respiration, mangrove tree sap flow from two species ( Avicennia germinans , Rhizophora mangle ), and individual tree and stand water use, from which we developed carbon (C) budgets for +N and +P vs. control simulations as applied to DDNWR’s 1112 ha mangrove area. Many of the measured response variables provided hints of subtle changes in response to +P rather than +N, which were compounded when scaled. From this, we found that additional P loading is expected to stimulate CO 2 uptake via net ecosystem exchange of C, likely pressing the system beyond metabolic capacity and leading to a projected 41% increase in lateral C export to the estuary. Additional lateral C export is concomitant to a reduction in vertical soil surface elevation with +P. Furthermore, an inability of DDNWR’s mangroves to bury additional P and a release of P-bound ions to lateral export may exacerbate estuarine eutrophication. We also modelled the effect of sea-level rise influences on DDNWR’s mangroves through 2100 using a soil cohort model (WARMER-Mangroves) and found that the mangroves may be resilient to current rates of sea-level rise into the future but may also be susceptible to moderate accelerations. Greater eutrophication could create additional vulnerabilities to mangrove submergence, especially to basin mangroves where P concentrations are high and already reducing soil surface elevations in some mangroves. Our results suggest that amelioration of current P concentrations and avoidance of additional P loading to Sanibel Island’s mangroves are management options to consider.
In 1975, the Federal government responded to the need for establishing national expertise in wildlife health by creating the National Wildlife Health Center (NWHC), a facility within the Department of the Interior; the NWHC is the only national center dedicated to wildlife disease detection, control, and prevention. Its mission is to provide national leadership to safeguard wildlife and ecosystem health through active partnerships and exceptional science. Comparisons are often made between the NWHC, which strives to protect the health of our Nation’s wildlife, and the Centers for Disease Control and Prevention (CDC), which strive to protect public health. The NWHC, a science center of the U.S. Geological Survey (USGS) with specialized laboratories, works to safeguard the Nation’s wildlife from diseases by studying the causes and drivers of these threats, and by developing strategies to prevent and manage them. In addition to the main campus, located in Madison, Wisconsin, the NWHC also operates the Honolulu Field Station that addresses wildlife health issues in Hawaii and the Pacific Region.
Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing salt marsh management decisions at the Chincoteague National Wildlife Refuge in Virginia. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of 12 salt marsh management units within the refuge and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that would be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per salt marsh management unit, that would maximize total management benefits at different cost constraints at the refuge scale. Results indicated that, for the objectives and actions considered here, total management benefits may increase consistently up to approximately $ 2.5 million, but that further expenditures may yield diminishing return on investment. For multiple salt marsh management units, a scenario incorporating managing grazing practices within the marsh was selected to maximize benefits while constraining total costs for the refuge at less than $ 2.5 million. Thin-layer deposition was predicted to increase the total management benefit substantially, but at considerable total costs ( $ 2.5 million to $ 83 million). The prototype presented here provides a framework for decision making at the Chincoteague National Wildlife Refuge that can be updated as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuge.
Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing tidal marsh management decisions at the Moosehorn National Wildlife Refuge in Maine. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of four marsh management units within the refuge, totaling about 13 hectares, and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that could be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per marsh management unit, that could maximize total management benefits at different cost constraints at the refuge scale. Results indicated that, for the objectives and actions considered here, total management benefits may increase consistently up to $ 1,000, and may continue to increase at a lower rate with further expenditures. Potential management actions in optimal portfolios at total costs less than or equal to $ 1,000 included improving nesting habitat for Ammodramus nelsoni (Nelson’s sparrow) or restoring hydrologic connections to the upper marsh in one marsh management unit (Hobart Stream West). The potential management benefits were derived from expected increases in the density of nekton and of spiders (as an indicator of trophic health). The prototype presented here does not resolve management decisions; rather, it provides a framework for decision making at the Moosehorn National Wildlife Refuge that can be updated for implementation as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuge.
Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing salt marsh management decisions at the Bombay Hook National Wildlife Refuge in Delaware. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of eight salt marsh management units within the refuge and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that would be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per salt marsh management unit, that would maximize total management benefits at different cost constraints at the refuge scale. Results indicated that for the objectives and actions considered here, total management benefits would increase consistently up to approximately \$300,000, but that further expenditures would yield diminishing return on investment. Management actions selected within optimal portfolios at total costs less than \$300,000 included hydrologic restoration, recontouring adjacent uplands to facilitate marsh migration, and burning the marsh. The prototype presented here provides a framework for decision making at the Bombay Hook National Wildlife Refuge that can be updated as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuge.
The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service collected data on water and bottom-sediment chemistry to be used to evaluate a new water rights acquisition program designed to enhance wetland habitat in Stillwater National Wildlife Refuge and in Lahontan Valley, Churchill County, Nevada. The area supports habitat critical to the feeding and resting of migratory birds travelling the Pacific Flyway. Information about how water rights acquisitions may affect the quality of water delivered to the wetlands is needed by stakeholders and Stillwater National Wildlife Refuge managers in order to evaluate the effectiveness of this approach to wetlands management. A network of six sites on waterways that deliver the majority of water to Refuge wetlands was established to monitor the quality of streamflow and bottom sediment. Each site was visited every 4 to 6 weeks and selected water-quality field parameters were measured when flowing water was present. Water samples were collected at varying frequencies and analyzed for major ions, silica, and organic carbon, and for selected species of nitrogen and phosphorus, trace elements, pharmaceuticals, and other trace organic compounds. Bottom-sediment samples were collected for analysis of selected trace elements. Dissolved-solids concentrations exceeded the recommended criterion for protection of aquatic life (500 milligrams per liter) in 33 of 62 filtered water samples. The maximum arsenic criterion (340 micrograms per liter) was exceeded twice and the continuous criterion was exceeded seven times. Criteria protecting aquatic life from continuous exposure to aluminum, cadmium, lead, and mercury (87, 0.72, 2.5, and 0.77 micrograms per liter, respectively) were exceeded only once in filtered samples (27, 40, 32, and 36 samples, respectively). Mercury was the only trace element analyzed in bottom-sediment samples to exceed the published probable effect concentration (1,060 micrograms per kilogram).