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At least 685 records · Page 38Linked to original sources
USGS2019

Effects of microcystin-LR on juvenile Lost River suckers (Deltistes luxatus) during feeding trials, Upper Klamath Lake, Oregon, 2014−16

Executive Summary Historically, populations of Lost River suckers ( Deltistes luxatus ) of the Upper Klamath Basin were so numerous that they were commercially harvested; however, declining numbers throughout the 20th century led to the listing of the species under the United States Endangered Species Act in 1988. Habitat destruction, poor water quality, competition with (and predation by) nonnative species, especially fathead minnows ( Pimephales promelas ) and yellow perch ( Perca flavescens ), are hypothesized as primary causes of population decline (U.S. Fish and Wildlife Service, 2013). Age data indicate that almost all adult suckers presently in Upper Klamath Lake spawning populations were hatched in the early 1990s. While entrainment of young fish (especially larvae) may contribute, catch-at-length and age data suggest consistently high mortality during the first year of life may be preventing the recruitment of young adults. The specific causes of juvenile sucker mortality are unknown; however, the absence of juvenile suckers in trap net catches coincides with degraded water quality associated with the decay of cyanobacteria blooms and exposure to toxic microcystin produced by Microcystis cyanobacteria. Water-quality data collected in Upper Klamath Lake from 2011 to 2016 suggest that microcystin concentrations in Upper Klamath Lake reached potentially lethal levels based on literature findings from studies on a variety of fish species. We conducted a laboratory feeding trial to determine if microcystin toxicity could potentially be a direct cause of juvenile Lost River sucker mortality. We examined the effects of environmentally relevant doses of microcystin on the survival and health of hatchery-reared juvenile Lost River suckers. Results from this laboratory study suggest that Lost River suckers are very tolerant of the microcystin-LR toxin. Histopathological analysis revealed no evidence of tissue changes associated with microcystin-LR exposure. Although no direct effects of microcystin-LR exposure were detected, suckers could potentially be negatively affected through added energy expenditures and stress associated with excretion of microcystin. Furthermore, microcystin may adversely affect other organisms in Upper Klamath Lake that could alter food availability or habitat of the suckers.

Oregon↗
USGS2015

Translating climate change effects on species into everyday language: an example of more driving and less fishing

Climate change is expected to result in widespread changes in species distributions (e.g., shifting, shrinking, expanding species ranges; e.g., Parmesan and Yohe, 2003), especially for freshwater fish species (Heino et al. 2009). Although anglers and other resource users could be greatly affected by changes in species distributions, predicted changes are rarely reported in ways that can be easily understood by the general public. In contrast, climate science that more directly affects human welfare or livelihoods is often more readily communicated to the general public because it is of greater concern or closely related to everyday life. For example, most people can readily interpret how increases in the number of “hot” days above a given temperature threshold might affect their lives, and property owners in coastal areas can use predictive maps to determine how they might be affected by sea level rise (for more examples, see the Third National Assessment of the U.S. Environmental Protection Agency at globalchange.gov ). However, the effects of climate change on species are usually reported to the general public using summary metrics or maps designed to communicate concepts that are not normally encountered in everyday life, including changes in habitat suitability, range shifts, or increasing risks from disease or extreme events (e.g., National Audubon Society 2009; Groffman et al. 2014). Though these metrics are necessary, meaningful, and understood by scientists, many people lack the necessary training and background to readily understand them. Further, scientists and nonscientists alike may struggle to convert these metrics into a currency that directly affects day-to-day life. Climate science is a complex issue, and we argue that when communicating potential responses of vegetation, fish, and wildlife to nonscientists, creative thinking with respect to the currency of communication will facilitate discussions between scientists, policy makers, and the public. We posit that with some additional thought and relatively simple summaries, the responses of fish and other species to climate change can be translated into everyday language that will facilitate climate science communication. Although such translations are rare, one example of this type of creativity is the translation from changes in habitat suitability for tree species to potential reductions in maple syrup production (West over 2012), which is arguably more interesting and understandable for the general public. Similar translations could be especially important for communicating climate change effects on game fish and other species that are socially and economically important to large groups of people. We demonstrate this translation by communicating the potential effects of climate change on the distribution of a coldwater fish species, the eastern Brook Trout Salvelinus fontinalis . Rather than communicating the potential forecasted contraction of the Brook Trout's distribution in terms of habitat loss, we report the predicted increases in the driving distance to streams likely offering Brook Trout angling opportunities under a climate change scenario. Travel costs based on distance have been widely used to value ecosystem services such as angling under climate change scenarios (e.g., Pendleton and Mendelsohn 1998; Mendelsohn and Markowski 1999; Ahn et al. 2000) but, to the best of our knowledge, have not been used for communicating potential changes to the public despite the intrinsic link to everyday life.

New York, Pennsylvania↗
USGS2025

Evaluating elk distribution and conflict under proposed management alternatives at the National Elk Refuge in Jackson, Wyoming

We evaluated measurable attributes describing the current and future distribution of Cervus elaphus canadensis (elk) across a region surrounding Jackson, Wyoming, for five feedground management alternatives proposed by the U.S. Fish and Wildlife Service as a revision to the 2007 “Bison and Elk Management Plan” of the National Elk Refuge. A resource selection function evaluated measurable attributes of interest to managers, including elk use of private property and sensitive habitat types at monthly timesteps and varying winter conditions. The study area boundaries were created through an expert elicitation process and consist of the Jackson Elk Herd Unit, Grand Teton National Park, the National Elk Refuge, and the northern third of the Fall Creek Elk Herd Unit. For each of the five alternatives, we distributed monthly elk numbers calculated in a concurrent analysis that simulated chronic wasting disease dynamics in this system for 20 years. Measurable attributes representing potential elk use of (1) private property, (2) cattle properties as an index of Brucella abortus risk, and sensitive habitats consisting of (3) Populus tremuloides Michx. (quaking aspen), (4) Populus angustifolia E. James (narrowleaf cottonwood), and (5) Salix L. (willow) in core winter use areas all closely followed the declines of elk abundance projected by the elk chronic wasting disease model. After 20 years, the continue feeding alternative ranked most favorably in terms of limiting elk days on private property and reducing brucellosis risk from elk to cattle because this alternative concentrated elk on the National Elk Refuge and resulted in the lowest elk population sizes. However, other management alternatives, including increase harvest and reduce feeding, tended to limit elk use of sensitive quaking aspen, narrowleaf cottonwood, and willow habitats during winter (December–April).

Wyoming↗
USGS2025

Evaluating elk distribution and conflict under proposed management alternatives at the National Elk Refuge in Jackson, Wyoming

We evaluated measurable attributes describing the current and future distribution of Cervus elaphus canadensis (elk) across a region surrounding Jackson, Wyoming, for five feedground management alternatives proposed by the U.S. Fish and Wildlife Service as a revision to the 2007 “Bison and Elk Management Plan” of the National Elk Refuge. A resource selection function evaluated measurable attributes of interest to managers, including elk use of private property and sensitive habitat types at monthly timesteps and varying winter conditions. The study area boundaries were created through an expert elicitation process and consist of the Jackson Elk Herd Unit, Grand Teton National Park, the National Elk Refuge, and the northern third of the Fall Creek Elk Herd Unit. For each of the five alternatives, we distributed monthly elk numbers calculated in a concurrent analysis that simulated chronic wasting disease dynamics in this system for 20 years. Measurable attributes representing potential elk use of (1) private property, (2) cattle properties as an index of Brucella abortus risk, and sensitive habitats consisting of (3) Populus tremuloides Michx. (quaking aspen), (4) Populus angustifolia E. James (narrowleaf cottonwood), and (5) Salix L. (willow) in core winter use areas all closely followed the declines of elk abundance projected by the elk chronic wasting disease model. After 20 years, the continue feeding alternative ranked most favorably in terms of limiting elk days on private property and reducing brucellosis risk from elk to cattle because this alternative concentrated elk on the National Elk Refuge and resulted in the lowest elk population sizes. However, other management alternatives, including increase harvest and reduce feeding, tended to limit elk use of sensitive quaking aspen, narrowleaf cottonwood, and willow habitats during winter (December–April).

Wyoming↗
USGS2021

Informing future condition scenario planning for habitat specialists of the imperiled pine rockland ecosystem of South Florida

This project evaluated habitat conditions for two species found in the imperiled pine rockland ecosystem—the Rim Rock Crowned Snake ( Tantilla oolitica ) and the Key Ring-Necked Snake ( Diadophis punctatus acricus ). The Rim Rock Crowned Snake historically occurred in eastern Miami-Dade County (hereafter, mainland) as well as throughout the Florida Keys, whereas the Key Ring-Necked Snake occurs only in lower Florida Keys (Enge et al. 2004; Mays and Enge 2016). Both species are very elusive, small (< 20 cm in length) and primarily fossorial. Pine rockland habitat is rapidly disappearing in South Florida, with < 3 percent of its original extent remaining. Saltwater intrusion from hurricanes and sea-level rise (SLR), and human development pose the greatest threats to the longevity of this ecosystem which, in turn, places species that are endemic to this unique habitat at risk of extinction. The Rim Rock Crowned Snake and the Key Ringed-Necked Snake are being considered for listing by the U.S. Fish and Wildlife Service (USFWS). To aid the agency’s decision, it must be able to forecast species’ responses to potential future environmental conditions, as well as to different conservation and management actions. Yet, the information needed to complete these forecasts—such as population trends, life history traits, habitat use, and future land use and climate conditions—is often lacking for most rare species. This is especially problematic for assessments of species resiliency to changes in climate and land use. When these types of data are lacking, information on habitat quality can be used to help determine how a species will respond to change. First, this project gathered current and historical records for both species from various sources such as museum specimens, inventories, and other personal account. Then, we identified potential future changes in habitat that could result from different management actions, such as habitat acquisition or restoration, and environmental conditions, such as changes in the frequency and intensity of tropical storms and rates of SLR. Researchers then explored the potential impacts of these habitat condition changes on the Rim Rock Crowned Snake and Key Ring-Necked Snake. This information can be used by the USFWS to help make decisions about the need to protect these species under the Endangered Species Act and could inform the conservation, management, and recovery of other at-risk species found in the pine rockland ecosystem. This work supports the Secretary of Interior’s priority to create a conservation stewardship legacy by using science to identify best practices to manage land and water resource and adapt to changes in the environment.

Florida↗
USGS2010

Power to detect trends in Missouri River fish populations within the Habitat Assessment Monitoring Program

As with all large rivers in the United States, the Missouri River has been altered, with approximately one-third of the mainstem length impounded and one-third channelized. These physical alterations to the environment have affected the fish populations, but studies examining the effects of alterations have been localized and for short periods of time, thereby preventing generalization. In response to the U.S. Fish and Wildlife Service Biological Opinion, the U.S. Army Corps of Engineers (USACE) initiated monitoring of habitat improvements of the Missouri River in 2005. The goal of the Habitat Assessment Monitoring Program (HAMP) is to provide information on the response of target fish species to the USACE habitat creation on the Lower Missouri River. To determine the statistical power of the HAMP and in cooperation with USACE, a power analysis was conducted using a normal linear mixed model with variance component estimates based on the first complete year of data. At a level of 20/16 (20 bends with 16 subsamples in each bend), at least one species/month/gear model has the power to determine differences between treated and untreated bends. The trammel net in September had the most species models with adequate power at the 20/16 level and overall, the trammel net had the most species/month models with adequate power at the 20/16 level. However, using only one gear or gear/month combination would eliminate other species of interest, such as three chub species (Macrhybopsis meeki, Macrhybopsis aestivalis, and Macrhybopsis gelida), sand shiners (Notropis stramineus), pallid sturgeon (Scaphirhynchus albus), and juvenile sauger (Sander canadensis). Since gear types are selective in their species efficiency, the strength of the HAMP approach is using multiple gears that have statistical power to differentiate habitat treatment differences in different fish species within the Missouri River. As is often the case with sampling rare species like the pallid sturgeon, the data used to conduct the analyses exhibit some departures from the parametric model assumptions. However, preliminary simulations indicate that the results of this study are appropriate for application to the HAMP study design.

Open-File Report↗
USGS2023

Haliaeetus leucocephalus (bald eagle) and Aquila chrysaetos (golden eagle) mortality and exposure to lead, mercury, and anticoagulant rodenticides in eight western and midwestern States, 2014–17

The U.S. Geological Survey National Wildlife Health Center measured environmental contaminants in Haliaeetus leucocephalus (bald eagles) and Aquila chrysaetos (golden eagles) to evaluate dietary exposure to lead, mercury, and anticoagulant rodenticides (AR), all of which were identified by U.S. Fish and Wildlife Service as a priority issue of concern for Mountain Prairie Region 6. Data were needed to inform U.S. Fish and Wildlife Service regional programs aimed at reducing exposure to these substances. Carcasses of bald eagles ( n =172) and golden eagles ( n =142) collected from North and South Dakota, Montana, Wyoming, Colorado, Utah, Nebraska, and Kansas between 2014 and 2017 were assessed for cause of death and liver lead, mercury, and AR level concentrations. Trauma, electrocution, and lead poisoning were the three leading causes of death, affecting 51 percent, 21 percent, and 20 percent of eagles, respectively. Trauma was the leading cause of death for both species, whereas lead poisoning was the second leading cause of death for bald eagles (31 percent) and was only diagnosed as the cause of death in 7 percent of golden eagles. Elevated lead concentrations within the range of subclinical or clinical poisoning (greater than [>] 2 milligrams per kilogram [mg/kg] wet weight) were present in 25 percent of eagles tested, including 36 percent of bald eagles and 11 percent of golden eagles. No association was detected among lead exposure and trauma, electrocution, or infectious disease. Mercury concentrations were considered high (>80 mg/kg dry weight) for only 2 percent of bald eagles and no golden eagles. Brodifacoum was the most common AR detected, present in 56 percent of eagles, including 70 percent of bald eagles and 39 percent of golden eagles; however, death was not directly attributed to AR toxicosis in any case. Results of this study provide baseline data on common causes of mortality and threats to eagles in Region 6 from lead, mercury, and rodenticide exposure and can be used to inform management decisions.

Open-File Report↗
USGS2020

Research priorities for migratory birds under climate change—A qualitative value of information assessment

The mission of the U.S. Geological Survey National Climate Adaptation Science Center is to provide actionable, management-relevant research on climate change effects on ecosystems and wildlife to U.S. Department of the Interior bureaus. Providing this kind of useful scientific information requires understanding how natural-resource managers make decisions and identifying research priorities that support those decision-making processes. Migratory bird management and conservation of migratory bird habitat are central components of the U.S. Department of the Interior’s mission. In particular, the U.S. Fish and Wildlife Service has an intensive, complex decision-making process for identifying high-priority parcels of land that will contribute to migratory bird conservation through permanent acquisition or easement. Climate change introduces several uncertainties into this decision-making process, and additional climate change research should help to support more informed decision making regarding habitat acquisition. Not all climate change related uncertainties, however, will have a meaningful effect on acquisition decisions; therefore, understanding which uncertainties have the most potential to alter decision making is crucial. This document summarizes a multiyear effort to clarify the major sources of climate change uncertainty that affect migratory bird management and to articulate related research priorities. We worked with U.S. Fish and Wildlife Service staff to assess the primary ways in which climate change is likely to affect migratory birds and their habitats; to clarify uncertainties surrounding these effects; and to assess how uncertainties may affect habitat acquisition decisions. Using a modified structured decision-making approach, we assessed a set of hypotheses about how climate change will affect migratory birds and their habitats. Then, we used a qualitative value of information assessment to rank the most important topics for future research. The ranking process was built on an assessment of three primary characteristics: the magnitude of uncertainty, the topic’s relevance to habitat acquisition decision making, and the feasibility of reducing the uncertainty. Based on the results of this process, high-priority topics for future research include the following: The effects of rising temperatures on spatial distributions of migratory birds during the breeding and nonbreeding seasons; Climate-driven changes to avian community composition through homogenization and loss of specialists; The effects of decreased precipitation on abundance in the breeding season; and The effects of rising temperatures on abundance in the nonbreeding season. In addition to describing high-priority research needs, this document provides a summary of the methodology used to identify, assess, and rank uncertainties. This method was developed for a climate change related topic where a full quantitative value of information approach may not be feasible. The results and methodology described here may be useful for U.S. Geological Survey and other science-funding agencies interested in improving the applicability of their research to natural-resource management decision making.

Circular↗
USGS2020

Ecological forecasting—21st century science for 21st century management

Natural resource managers are coping with rapid changes in both environmental conditions and ecosystems. Enabled by recent advances in data collection and assimilation, short-term ecological forecasting may be a powerful tool to help resource managers anticipate impending near-term changes in ecosystem conditions or dynamics. Managers may use the information in forecasts to minimize the adverse effects of ecological stressors and optimize the effectiveness of management actions. To explore the potential for ecological forecasting to enhance natural resource management, the U.S. Geological Survey (USGS) convened a workshop titled "Building Capacity for Applied Short-Term Ecological Forecasting" on May 29—31, 2019, with participants from several Federal agencies, including the Bureau of Land Management, the U.S. Fish and Wildlife Service, the National Park Service, and the National Oceanic and Atmospheric Administration as well as all mission areas within the USGS. Participants broadly agreed that short-term ecological forecasting—on the order of days to years into the future—has tremendous potential to improve the quality and timeliness of information available to guide resource management decisions. Participants considered how ecological forecasting could directly affect their agency missions and specified numerous critical tools for addressing natural resource management concerns in the 21st century that could be enhanced by ecological forecasting. Given this breadth of possible applications for forecast products, participants developed a repeatable framework for evaluating potential value of a forecast product for enhancing resource management. Applying that process to a large list of forecast ideas that were developed in a brainstorming session, participants identified a small set of promising forecast products that illustrate the value of ecological forecasting for informing resource management. Workshop outcomes also include insights about important likely obstacles and next steps. In particular, reliable production and delivery of operational ecological forecasts will require a sustained commitment by research agencies, in partnership with resource management agencies, to maintain and improve forecasting tools and capabilities.

Open-File Report↗
USGS2017

The Wetland and Aquatic Research Center strategic science plan

Introduction The U.S. Geological Survey (USGS) Wetland and Aquatic Research Center (WARC) has two primary locations (Gainesville, Florida, and Lafayette, Louisiana) and field stations throughout the southeastern United States and Caribbean. WARC’s roots are in U.S. Fish and Wildlife Service (USFWS) and National Park Service research units that were brought into the USGS as the Biological Research Division in 1996. Founded in 2015, WARC was created from the merger of two long-standing USGS biology science Centers—the Southeast Ecological Science Center and the National Wetlands Research Center—to bring together expertise in biology, ecology, landscape science, geospatial applications, and decision support in order to address issues nationally and internationally. WARC scientists apply their expertise to a variety of wetland and aquatic research and monitoring issues that require coordinated, integrated efforts to better understand natural environments. By increasing basic understanding of the biology of important species and broader ecological and physiological processes, this research provides information to policymakers and aids managers in their stewardship of natural resources and in regulatory functions. This strategic science plan (SSP) was developed to guide WARC research during the next 5–10 years in support of Department of the Interior (DOI) partnering bureaus such as the USFWS, the National Park Service, and the Bureau of Ocean Energy Management, as well as other Federal, State, and local natural resource management agencies. The SSP demonstrates the alignment of the WARC goals with the USGS mission areas, associated programs, and other DOI initiatives. The SSP is necessary for workforce planning and, as such, will be used as a guide for future needs for personnel. The SSP also will be instrumental in developing internal funding priorities and in promoting WARC’s capabilities to both external cooperators and other groups within the USGS.

Open-File Report↗
USGS2022

Preliminary models relating lake level gate operation and discharge at Reelfoot Lake in Tennessee and Kentucky

Preliminary models for gate operations at the new outlet control structure for Reelfoot Lake were developed by the U.S. Geological Survey, using calibrated ratings of the lift gates, to support the U.S. Fish and Wildlife Service in managing lake level. In 2018, the old structure at the outlet of Reelfoot Lake was buried and lake level control was transferred to a new structure. The transition from lake-level management of the old control structure to the new control structure was documented using historical lake level and discharge measurements and records of stop-log management from March 7, 2013, to August 12, 2018. Discharge into Running Reelfoot Bayou was determined using a standard stage-discharge rating curve. Discharge measured using an acoustic Doppler current profiler was used to calibrate gate-discharge equations for free and submerged orifice flow at the new structure. Two lake operation models, one for the summer season and another for the winter season, are provided for the new structure based on data from this period. The summer operation model is based on operation of the gates once the lake level exceeds an elevation of 282.7 feet (ft) above the North American Vertical Datum of 1988 (NAVD 88). Free flow begins when lake level reaches 282.3 ft above NAVD 88 and becomes transitional once the lake level exceeds 282.8 ft above NAVD 88. Submerged flow begins once the lake level reaches 283 ft above NAVD 88 and the tail-water depth is above critical flow depth. The winter operation model is based on operation of the gates once the lake level exceeds 283.2 ft above NAVD 88. Submerged flow begins when the lake rises to an elevation of 283.5 ft above NAVD 88 and the tail-water depth is above critical flow depth.

Kentucky, Tennessee↗
USGS1991

User's guide to the wetland creation/restoration data base, version 2

Wetland creation or restoration projects are frequently proposed as mitigation for unavoidable wetland losses, as components of wetland enhancement programs, and as tools to accomplish specific objectives such as waterfowl production or flood control. There is considerable controversy concerning the effectiveness of such projects as well as the most appropriate and efficient techniques to employ. The importance of the resource and the long time scales involved in fully evaluating a creation or restoration effort make it imperative to consider existing information as fully as possible in the development and evaluation of wetland creation or restoration proposals. To aid in the evaluation of wetland/creation efforts, the U.s. Fish and Wildlife Service (FWS), National Ecology Research Center, has developed the Wetland Creation/Restoration (WCR) Data Base. The data base is a highly indexed or keyworded bibliography of wetland creation or restoration articles. ("Articles" refers to any type of publication that deals specifically with wetland creation/restoration projects or studies.) The scope of the articles is international, although most of them are concerned with projects conducted in the United States. Information coded for each article includes author; citation; type of wetland and its location in terms of state, ecoregion, and FWS region; type of study undertaken; objectives in creating or restoring the wetland; actions performed to realize those objectives; length of time encompassed by the study; evaluation of results and responses to the wetland creation/restoration actions; and a listing of plant species significant to the project. A brief annotation summarizes the article and includes any significant additional information that may not be adequately reflected in the above described fields. Many of these articles describe only one or two components of a total wetland restoration effort. Planning a project that is designed to restore a wetland system (including at least some of its functions) is similar to constructing a picture from a number of puzzle pieces--missing pieces represent data gaps or information that is not available. Articles range from specific case studies, to overviews of restoration methods and techniques, to planning restoration projects and assessing programmatic and administrative backgrounds and interactions. In this data base, the term "restoration" is applied loosely to include rehabilitation of wetlands. It may refer to a number of situations or actions including, but not limited to: 1. breaching dikes or plugging drains; 2. water pollution clean-up; 3. conversion of eutrophic conditions; 4. wastewater treatment; 5. recolonization of previously disturbed or denuded areas; 6. amelioration of adverse conditions (erosion, wave, or wind action); 7. soil treatment --mulching, fertilization; 8. rerouting streams --may include construction of meander patterns; 9. monitoring natural vegetation; or 0. excluding grazers (geese, cattle) and monitoring results. This report describes the format and content of Version 2 of the WCR data base. Version 2 differs from the previous version described in SchnellerMcDonald et al. (1988): several fields have been dropped and condensed and new records have been added. Version 2 includes all records distributed with the earlier version and its updates. We recommend you replace any previous version with Version 2.

Book↗
USGS2005

Grass buffers for playas in agricultural landscapes: A literature synthesis

We summarize current knowledge about grass buffers for protecting small, isolated wetlands in agricultural contexts, including information relevant to protecting playas from runoff containing sediments, nutrients, pesticides, and other contaminants, and information on how buffers may affect densities and productivity of grassland birds. Land-uses surrounding the approximately 60,000 playas within the Playa Lakes Region (PLR), including intensive agriculture, feedlots, and oil extraction, can contribute to severe degradation of playas. Farming and grazing can lead to significant sedimentation in nearby playas, eliminating their ability to hold water, support the region&rsquo;s biodiversity, or adequately recharge aquifers. Contaminants further degrade habitats and threaten the water quality of underlying aquifers, including the Ogallala Aquifer. Grass buffers hold promise as a management tool to reduce the amount of sediments and contaminants from agricultural runoff that enters playas. Effective buffer width is determined by acceptable sediment-reduction levels, potential water flow and velocity, landscape and soil variables, buffer species, and vegetation structure. Various models have been developed to predict buffer effectiveness; however, most of these models, including those provided by the Natural Resource Conservation Service (NRCS), remain unvalidated. The majority of buffer-effectiveness literature is based on simulated conditions in experimental trays or plots; no published studies of buffer design or effectiveness specifically address playas. Nonetheless, some general patterns have emerged regarding buffer design/effectiveness. Buffers 10&ndash;60 m wide are generally considered adequate for trapping most sediments, although in some cases buffers need to be >200 m. The U.S. Fish and Wildlife Service Partners for Wildlife Program in the Southern High Plains recommend a buffer width of ~33 m planted with a diverse mix of native shortgrasses and mixed grasses as a starting point. Most dissolved contaminants, however, are removed from runoff only when they infiltrate the soil, where microbes or other processes can break down or sequester contaminants. Promoting runoff infiltration requires wider buffers with denser stem densities than those required for filtering sediments, which may result in hydrological changes in playas. Ultimately, the balance between runoff and infiltration determines whether or not water eventually reaches a given basin. Long-term buffer effectiveness requires regular maintenance, including excavation to remove overburdens of sediments, repairing vegetation damage, and removing over-mature vegetation or invasions of noxious weeds. Buffers may not be enough to protect playas; best management practices (BMPs; e.g., conservation tillage, contour tilling, and mulching herbicides into soil after application) that diminish soil erosion and contaminant runoff also may be necessary. Nutrient loads in runoff can be minimized by balancing nutrient input with nutrient requirements for livestock and crops. Pesticide application practices also require careful evaluation. Mowing or grazing rather than use of herbicides offer alternatives for suppressing invasive or undesirable plant species in buffers. Future research should entail multiple-scale approaches at regional, wetland-complex, and individual watershed scales. Information needs include direct measures of buffer effectiveness in &lsquo;real-world&rsquo; systems, refinement and field tests of buffer-effectiveness models, how buffers may affect floral and faunal communities of playas, and basic ecological information on playa function and playa wildlife ecology. Understanding how wildlife communities respond to patch size and habitat fragmentation is crucial for addressing questions regarding habitat quality of grass buffers in playa systems.

Open-File Report↗
USGS2017

Chemical quality of water and bottom sediment, Stillwater National Wildlife Refuge, Lahontan Valley, Nevada

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).

Nevada↗
USGS2013

Survey of bats on Columbia National Wildlife Refuge, Washington, December 2011-April 2012

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.

Oregon;Washington↗
USGS2019

Optimization of salt marsh management at the Chincoteague National Wildlife Refuge, Virginia, through use of structured decision making

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.

Virginia↗
USGS2020

Analyses on subpopulation abundance and annual number of maternal dens for the U.S. Fish and Wildlife Service on polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska

The long-term persistence of polar bears ( Ursus maritimus ) is threatened by sea-ice loss due to climate change, which is concurrently providing an opportunity in the Arctic for increased anthropogenic activities including natural resource extraction. Mitigating the risk of those activities, which can adversely affect the population dynamics of the southern Beaufort Sea (SBS) subpopulation, is an emerging challenge as polar bears become more reliant on land and come into more frequent contact with humans. The Marine Mammal Protection Act and Endangered Species Act require the U.S. Fish and Wildlife Service to determine whether industrial activities will have a negligible impact on the SBS subpopulation. Information important to making that determination includes estimates of subpopulation abundance and the number of maternal dens likely to be present in areas where industrial activities occur. We analyzed mark-recapture data collected from SBS polar bears sampled in Alaska during 2001–16 using multistate Cormack-Jolly-Seber models. Estimated survival rates were relatively high during 2001–03, lower during 2004–08, then higher during 2009–15 except for 2012. Estimated abundance in the Alaska part of the SBS was consistent with the estimated survival rates, declining from about 1,300 bears in 2003 to 525 bears in 2006 and then remaining generally stable during 2006–15. The point estimate for the Alaska part of the SBS in 2015, the last year in which abundance could be estimated, was 573 bears (95-percent credible interval = 232, 1,140 bears). To estimate the expected number of terrestrial dens likely to be present in a given region in a given year, we used a Bayesian modeling approach based on calculations derived from SBS demographic and denning data. We estimated that the entire SBS subpopulation produced 123 dens per year (median; 95-percent credible interval = 69, 198 dens), 66 (median; 95-percent credible interval = 35, 110 dens) of which were land-based. Most land-based dens were located between the Colville and Canning Rivers (which includes the Prudhoe Bay-Kuparuk industrial footprint), followed by the 1002 Area of the Arctic National Wildlife Refuge and the National Petroleum Reserve-Alaska.

Alaska↗
USGS2009

Estimation of Streamflow Characteristics for Charles M. Russell National Wildlife Refuge, Northeastern Montana

Charles M. Russell National Wildlife Refuge (CMR) encompasses about 1.1 million acres (including Fort Peck Reservoir on the Missouri River) in northeastern Montana. To ensure that sufficient streamflow remains in the tributary streams to maintain the riparian corridors, the U.S. Fish and Wildlife Service is negotiating water-rights issues with the Reserved Water Rights Compact Commission of Montana. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, conducted a study to gage, for a short period, selected streams that cross CMR, and analyze data to estimate long-term streamflow characteristics for CMR. The long-term streamflow characteristics of primary interest include the monthly and annual 90-, 80-, 50-, and 20-percent exceedance streamflows and mean streamflows (Q.90, Q.80, Q.50, Q.20, and QM, respectively), and the 1.5-, 2-, and 2.33- year peak flows (PK1.5, PK2, and PK2.33, respectively). The Regional Adjustment Relationship (RAR) was investigated for estimating the monthly and annual Q.90, Q.80, Q.50, Q.20, and QM, and the PK1.5, PK2, and PK2.33 for the short-term CMR gaging stations (hereinafter referred to as CMR stations). The RAR was determined to provide acceptable results for estimating the long-term Q.90, Q.80, Q.50, Q.20, and QM on a monthly basis for the months of March through June, and also on an annual basis. For the months of September through January, the RAR regression equations did not provide acceptable results for any long-term streamflow characteristic. For the month of February, the RAR regression equations provided acceptable results for the long-term Q.50 and QM, but poor results for the long-term Q.90, Q.80, and Q.20. For the months of July and August, the RAR provided acceptable results for the long-term Q.50, Q.20, and QM, but poor results for the long-term Q.90 and Q.80. Estimation coefficients were developed for estimating the long-term streamflow characteristics for which the RAR did not provide acceptable results. The RAR also was determined to provide acceptable results for estimating the PK1.5., PK2, and PK2.33 for the three CMR stations that lacked suitable peak-flow records. Methods for estimating streamflow characteristics at ungaged sites also were derived. Regression analyses that relate individual streamflow characteristics to various basin and climatic characteristics for gaging stations were performed to develop regression equations to estimate streamflow characteristics at ungaged sites. Final equations for the annual Q.50, Q.20, and QM are reported. Acceptable equations also were developed for estimating QM for the months of February, March, April, June, and July, and Q.50, Q.20, and QM on an annual basis. However, equations for QM for the months of February, March, April, June, and July were determined to be less consistent and reliable than the use of estimation coefficients applied to the regression equation results for the annual QM. Acceptable regression equations also were developed for the PK1.5, PK2, and PK2.33.

Scientific Investigations Report↗