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USGS2026

Fisheries sustainability: Perceptions from the ninth World Fisheries Congress

The World Fisheries Congress (WFC) is one of the largest global gatherings of fisheries professionals and scientists. It is held every 4 years with the purpose of sharing ideas and perspectives about new research, emerging issues, scientific breakthroughs, and governance related to fisheries science, industry, conservation, and management. The ninth WFC, held in Seattle (USA) in 2024, focused on fish and fisheries at the food–water–energy nexus and understanding fisheries sustainability from diverse perspectives. Fisheries sustainability is a goal shared globally that faces challenges across spatial scales from the implementation of good governance and accelerating anthropogenic pressures. Leveraging the unique opportunity to gain insights from WFC delegates, this study assesses perceptions of fisheries sustainability from diverse representation across career stage, geographic region, and professional and cultural backgrounds. Survey results show that respondents (i.e., WFC delegates who chose to take the survey) perceived limited progress towards fisheries sustainability, often with a variable and unclear definition of what sustainability entails. Fish were primarily valued from a provisioning resource perspective, with environmental aspects of fisheries management and conservation seen as the area with the most progress and the greatest needs, rather than economic or social dimensions of fisheries.

Fisheries↗

USGS2017

Using science to inform management and improve biological conservation in the Desert Renewable Energy Conservation Plan

The Mojave and Colorado deserts of southern California have been viewed as vast wilderness since early exploration and, until recently, were considered the most untrammeled among western landscapes in the contiguous lower 48 states (United States Department of Agriculture 1893; Leu et al. 2008). However, the factors that define desert wilderness—small human population, temperature differentials that create unrelenting winds, low rainfall, and cloudless skies—are attractive for renewable energy development. The demand for clean, renewable energy is a national and regional priority and has increased demand for large-scale solar and wind farms in the deserts, particularly in California. The need to balance these national and state energy priorities with existing natural resource and land conservation policies has emerged as a landscape-scale land-use planning initiative known as the Desert Renewable Energy Conservation Plan (DRECP). One of the primary goals for the DRECP was to establish Development Focus Areas (DFAs) where high-quality renewable energy potential of up to 20 gigawatts (GW) could be implemented by the year 2040. DFAs were designed to provide expedited project approvals in locations where environmental impacts could be managed and mitigated, and proximity to transmission corridors provides for the efficient dissemination of energy to users. The DRECP also aims to identify protections for natural resources, recreation, and cultural resources. This plan identifies 37 covered species that receive special consideration in the DRECP. Among the special considerations are climate adaptation requirements, such as the ability to maintain population connectivity through wildlife corridors, while protecting several special recreation areas and 32,000 known cultural sites that are dispersed throughout the region. We evaluated several particular aspects of the DRECP design and process. In particular, we examined land designations in relation to published studies on Mohave ground squirrel (Xerospermophilus mohavensis) habitat and genetic diversity patterns of a suite of broadly distributed desert animal species. The squirrel and its habitat are of particular interest because the entire range of the squirrel is encompassed by the DRECP. We describe the framework of the DRECP, provide a case study of how the DRECP accommodates the needs of the Mohave ground squirrel and its habitat, illustrate DFAs in relation to the genetic diversity of a broad range of terrestrial biota, and conclude with some observations on how land-use issues were resolved across the landscape under various scenarios.

Conference Paper↗

USGS2023

Leading the charge: A qualitative case-study of leadership conditions in collaborative environmental governance structures

Collaborative governance structures are increasingly common among natural resource managers. While studies have assessed the conditions under which collaborative action occurs, little emphasis has been placed on the role leadership may play in joint-jurisdictional systems. Management of species under the Endangered Species Act offers an opportunity to assess the collaboration of federal, state, and tribal resource agencies. The Gulf of Maine Distinct Population Segment of Atlantic salmon ( Salmo salar ) was managed under a structure called the Atlantic Salmon Recovery Framework (ASRF) from 2011 to 2019. Using the ASRF as a case study, we examined the influence of leadership approaches on perceived program efficacy, member buy-in, and experience through semi-structured interviews. Participant reflections revealed three major leadership themes that participants found inadequate: (1) shared goals, (2) transparency, and (3) trust. Collaborative approaches that foster these leadership conditions may increase adaptive capacity and the likelihood of sustained success in this, and other, environmental governance structures.

Journal of Environmental Management↗

USGS2016

Applications of genetic data to improve management and conservation of river fishes and their habitats

Environmental variation and landscape features affect ecological processes in fluvial systems; however, assessing effects at management-relevant temporal and spatial scales is challenging. Genetic data can be used with landscape models and traditional ecological assessment data to identify biodiversity hotspots, predict ecosystem responses to anthropogenic effects, and detect impairments to underlying processes. We show that by combining taxonomic, demographic, and genetic data of species in complex riverscapes, managers can better understand the spatial and temporal scales over which environmental processes and disturbance influence biodiversity. We describe how population genetic models using empirical or simulated genetic data quantify effects of environmental processes affecting species diversity and distribution. Our summary shows that aquatic assessment initiatives that use standardized data sets to direct management actions can benefit from integration of genetic data to improve the predictability of disturbance–response relationships of river fishes and their habitats over a broad range of spatial and temporal scales.

Fisheries↗

USGS2012

USGS Environmental health science strategy: providing environmental health science for a changing world: Public review release

America has an abundance of natural resources. We have bountiful clean water, fertile soil, and unrivaled national parks, wildlife refuges, and public lands. These resources enrich our lives and preserve our health and wellbeing. These resources have been maintained because of our history of respect for their value and an enduring commitment to their vigilant protection. Awareness of the social, economic, and personal value of the health of our environment is increasing. The emergence of environmentally driven diseases caused by environmental exposure to contaminants and pathogens is a growing concern worldwide. New health threats and patterns of established threats are affected by both natural and anthropogenic changes to the environment. Human activities are key drivers of emerging (new and re-emerging) health threats. Societal demands for land and natural resources, a better quality of life, improved economic prosperity, and the environmental impacts associated with these demands will continue to increase. Natural earth processes, climate trends, and related climatic events will add to the environmental impact of human activities. These environmental drivers will influence exposure to disease agents, including viral, bacterial, prion, and fungal pathogens, parasites, natural earth materials, toxins and other biogenic compounds, and synthetic chemicals and substances. The U.S. Geological Survey (USGS) defines environmental health science broadly as the interdisciplinary study of relations among the quality of the physical environment, the health of the living environment, and human health. The interactions among these three spheres are driven by human activities, ecological processes, and natural earth processes; the interactions affect exposure to contaminants and pathogens and the severity of environmentally driven diseases in animals and people. This definition provides USGS with a framework for synthesizing natural science information from across the Bureau and providing it to environmental, natural resource, agricultural, and public-health managers. The USGS is a Federal science agency with a broad range of natural science expertise relevant to environmental health. USGS provides scientific information and tools as a scientific basis for management and policy decision making. USGS specializes in science at the environment-health interface, by characterizing the processes that affect the interaction among the physical environment, the living environment, and people, and the resulting factors that affect ecological and human exposure to disease agents. This report describes a 10-year strategy that encompasses the portfolio of USGS environmental health science. It summarizes national environmental health priorities that USGS is best suited to address, and will serve as a strategic framework for USGS environmental health science goals, actions, and outcomes for the next decade. Implementation of this strategy is intended to aid coordination of USGS environmental health activities and to provide a focal point for disseminating information to stakeholders. The "One Health" paradigm advocated by the World Health Organization (WHO, 2011), and the American Veterinary Medicine Association (AVMA, 2008), among others, is based on a general recognition that the health of humans, animals, and the environment are inextricably linked. Thus, successful efforts to protect that health will require increased interdisciplinary research and increased communication and collaboration among the broader scientific and health community. This strategy is built upon that paradigm. The vision, mission, and five cornerstone goals of the USGS Environmental Health Science Strategy were developed with significant input from a wide range of stakeholders. Vision - The USGS is a premier source of the environmental health science needed to safeguard the health of the environment, fish, wildlife, and people. Mission - The mission of USGS in environmental health science is to contribute scientific information to environmental, natural resource, agricultural, and public-health managers, who use that science to support sound decision making. USGS provides the science to: - Goal 1: Identify, prioritize, and detect contaminants and pathogens of emerging environmental concern. - Goal 2: Reduce the impact of contaminants on the environment, fish, wildlife, and people. - Goal 3: Reduce the impact of pathogens on the environment, fish, wildlife, and people. - Goal 4: Discover the complex interactions and combined effects of exposure to contaminants and pathogens. - Goal 5: Prepare for and respond to environmental impacts and related health threats of natural and anthropogenic disasters. Goals 1 through 4 are intended to provide science to address environmental health threats in a logical order, from informing prevention and preparedness, to supporting systematic management response to environmental health issues. Goal 4 addresses the interaction among contaminants and pathogens, an issue of emerging concern in environmental health science. Goal 5 acknowledges the fact that natural and anthropogenic disasters can cause immediate and prolonged adverse environmental health threats. This strategy proposes that USGS take the following strategic science actions to achieve each of the five goals of this strategy: Goal 1: Identify, prioritize, and detect contaminants and pathogens of emerging environmental concern. - Strategic Science Action 1. - Prioritize contaminants and pathogens of emerging concern to guide research, detection, and management activities. - Strategic Science Action 2. - Conduct surveillance and monitoring to provide early warning of emerging health threats. - Strategic Science Action 3. - Develop approaches and tools that identify vulnerable environmental settings, ecosystems, and species. Goal 2: Reduce the impact of contaminants on the environment, fish, wildlife, and people. - Strategic Science Action 1. - Systematically characterize the sources, occurrence, transport and fate of environmental contaminants to guide efforts to manage and mitigate contamination. - Strategic Science Action 2. - Evaluate the threats of contamination on the health of the environment, fish, wildlife, and people, and inform the associated management and protection efforts. - Strategic Science Action 3. - Characterize potential human exposure to support establishment of health-based standards or guidelines and contamination-reduction efforts. Goal 3: Reduce the impact of pathogens on the environment, fish, wildlife, and people. - Strategic Science Action 1. - Determine the biotic and abiotic factors that control the ecology of infectious diseases affecting natural populations of aquatic and terrestrial species and potential transmission to other animals and humans. - Strategic Science Action 2. - Establish how natural and anthropogenic environmental changes affect the distribution and severity of infectious diseases in natural populations of aquatic and terrestrial species and potential transmission to other animals and humans. - Strategic Science Action 3. - Develop surveillance systems to identify changing patterns of disease activity in priority geographic areas. Goal 4: Discover the complex interactions and combined effects of exposure to contaminants and pathogens. - Strategic Science Action 1. - Identify how exposure to one class of disease agents (contaminants or pathogens) can make an organism more susceptible to effects from exposure to the other class of disease agents. - Strategic Science Action 2. - Implement interdisciplinary studies that characterize the effects of combined exposure to pathogens and contaminants. Goal 5: Prepare for and respond to the environmental impacts and related health threats of natural and anthropogenic disasters. - Strategic Science Action 1. - Establish a formal interdisciplinary science capability to rapidly assess the environmental health risks associated with disasters. - Strategic Science Action 2. - Enhance methods to anticipate, prepare for, and identify environmental, ecological, and related health impacts of future disasters. This strategy is one of seven USGS science strategies developed concurrently: - Climate and Land Use Change - Core Science Systems - Ecosystems - Energy and Mineral Resources - Environmental Health - Natural Hazards - Water. This strategy describes how USGS will address the highest priority environmental health issues facing the Nation. The ultimate intended outcome of this science strategy is prevention and reduction of adverse impacts to the quality of the environment, the health of our living resources, and human health. Communication with, and receiving input from, partners and stakeholders regarding their science needs is essential for successful implementation of this strategy. It is incumbent on USGS to reach out to all stakeholders to ensure that USGS efforts are focused on the highest priority environmental health issues and that products are provided in the most timely and usable form to all those who can use them. USGS must reach out to the scientific community, internally and externally, to ensure that our efforts are integrated with and take full advantage of the activities of others.

Open-File Report↗

USGS2018

Resilience and resistance in sagebrush ecosystems are associated with seasonal soil temperature and water availability

Invasion and dominance of exotic grasses and increased fire frequency threaten native ecosystems worldwide. In the Great Basin region of the western United States, woody and herbaceous fuel treatments are implemented to decrease the effects of wildfire and increase sagebrush ( Artemisia spp.) ecosystem resilience to disturbance and resistance to exotic annual grasses. High cover of the exotic annual cheatgrass ( Bromus tectorum ) after treatments increases fine fuels, which in turn increases the risk of passing over a biotic threshold to a state of increased wildfire frequency and conversion to cheatgrass dominance. Sagebrush ecosystem resilience to wildfire and resistance to cheatgrass depend on climatic conditions and abundance of perennial herbaceous species that compete with cheatgrass. In this study, we used longer‐term data to evaluate the relationships among soil climate conditions, perennial herbaceous cover, and cheatgrass cover following fuel management treatments across the environmental gradients that characterize sagebrush ecosystems in the Great Basin. We examined the effects of woody and herbaceous fuel treatments on soil temperature, soil water availability (13–30 and 50 cm depths), and native and exotic plant cover on six sagebrush sites lacking piñon ( Pinus spp.) or juniper ( Juniperus spp.) tree expansion and 11 sagebrush sites with tree expansion. Both prescribed fire and mechanical treatments increased soil water availability on woodland sites and perennial herbaceous cover on some woodland and sagebrush sites. Prescribed fire also slightly increased soil temperatures and especially increased cheatgrass cover compared to no treatment and mechanical treatments on most sites. Non‐metric dimensional scaling ordination and decision tree partition analysis indicated that sites with warmer late springs and warmer and wetter falls had higher cover of cheatgrass. Sites with wetter winters and early springs (March–April) had higher cover of perennial herbs. Our findings suggest that site resistance to cheatgrass after fire and fuel control treatments decreases with a warmer and drier climate. This emphasizes the need for management actions to maintain and enhance perennial herb cover, such as implementing appropriate grazing management, and revegetating sites that have low abundance of perennial herbs in conjunction with fuel control treatments.

Ecosphere↗

USGS2002

Hydrogeology and water quality of the Upper Three Runs aquifer in the vicinity of the Gibson Road Landfill, Fort Gordon, Georgia, June-November 1999

Fort Gordon military installation, a U.S. Department of the Army facility, is located in east-central Georgia southwest of Augusta. The military base operates a three-phase unlined landfill—Gibson Road Landfill— to store a variety of wastes. Phases I and II stored only household wastes, and these phases were discontinued during the mid–1990s. Fort Gordon currently (1999) operates Phase III of the landfill that stores only construction and demolition debris. Water-quality monitoring detected selected trace elements and organic compounds exceeding the maximum contaminant levels of the U.S. Environmental Protection Agency, National Primary Drinking Water Standards. The selected trace elements and organic compounds detected showed that contamination of ground water had occurred in the vicinity of the landfill. In 1999, the U.S. Geological Survey, in cooperation with the Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, began an assessment of the hydrogeology and water quality in shallow ground water in the vicinity of the Gibson Road Landfill to delineate the extent of a ground-water contamination plume in the vicinity of the landfill. Hydrogeologic units in the Augusta area include the Upper Three Runs aquifer, the Gordon aquifer, the Millers Pond aquifer, and the Dublin aquifer. Only the shallowest aquifer, Upper Three Runs, was penetrated during this study. The Upper Three Runs aquifer is composed of sediments of the Barnwell Group. Mostly, these sediments are highly permeable fine to medium, well-sorted sand with lenses of clay. Ground-water flow is from northwest to southeast and generally was unaffected by seasonal variation during the period of study (June–November 1999). Water-table altitudes in the landfill area for the study period ranged from 394 feet (ft) to 445 ft above sea level. Ground-water samples analyzed for organic compounds and selected trace elements by a U. S. Environmental Protection Agency (USEPA) approved statistical test revealed that increases in contaminant concentrations above the detection limits had occurred during March and September 1999 in five wells—one of which is located upgradient. These organic compounds, respective increases in concentration, and the wells in which they were detected are: methylene chloride—wells 28AA29 (24 parts per billion [ppb] and 46 ppb), 28AA30 (86 ppb and 130 ppb), and 28AA31 (240 ppb and 140 ppb); 1,1-dichloroethene—well 28AA31 (10 ppb and 5.7 ppb); 1,1-dichloroethane— wells 28AA30 (81 ppb and 140 ppb) and 28AA31 (200 ppb and 130 ppb); and 1,1,1-trichloroethane—well 28AA31 (61 ppb and 37 ppb). Although in some wells the concentration decreased from March to September, the median concentrations were still higher in certain groups. Trace element compounds, their respective increases in concentration, and the wells in which they were detected are: chromium—well 28AA30 (1,190 ppb), vanadium—well 28AA30 (104 ppb); barium—wells 28AA27 (42.2 ppb) and 28AA32 (140 ppb), and beryllium—well 28AA30 (6.3 ppb). These increases occurred in September, with the exception of chromium in well 28AA30, which occurred in March. Although a statistical test indicated increases in contaminant concentrations had occurred, water from wells 28AA27, 28AA30, 28AA31, and 28AA32 had a decrease in contaminant concentrations from February 1998 to September 1999. U.S. Environmental Protection Agency, National Primary Drinking Water Regulations Maximum Contaminant Levels (PMCLs), formerly (MCLs) were exceeded in water from four wells for organic compounds and in five wells by selected trace elements during the February 1998, March 1999, and September 1999 sampling periods. The concentrations for the following organic compounds and the associated wells are: methylene chloride (PMCL is 5 ppb)—wells 28AA27 (February, 37 ppb; March, 24 ppb; and September, 9.6 ppb), 28AA29 (February, 20 ppb; March, 24 ppb; and September, 46 ppb), 28AA30 (February, 50 ppb; March, 86 ppb; and September, 130 ppb), and 28AA31 (February, 330 ppb; March 240 ppb; and September, 140 ppb); vinyl chloride (PMCL is 2 ppb)—well 28AA29 (March, 3.6 ppb; and September, 4.4 ppb); 1,1-dichloroethene (PMCL is 7 ppb)—wells 28AA30 (March 10 ppb; and September, 17 ppb) and 28AA31 (February, 13 ppb; and March, 10 ppb); and 1,1,2-trichloroethane (PMCL is 5 ppb)—well 28AA30 (March, 33 ppb). Contaminant concentrations decreased in well 28AA31 from March to September 1999; however, concentrations still exceeded the PMCL. The concentrations for the following selected trace elements exceeding PMCL and the associated wells during the sampling periods February 1998, March 1999, and September 1999 are: mercury (PMCL is 2 ppb)—well 28AA24 (September, 2.82 ppb), well 28AA25 (February, 3.1 ppb; March, 2.11 ppb; and September, 2.28 ppb), and well 28AA30 (September, 2.82 ppb); arsenic (PMCL is 50 ppb)—well 28AA30 (February, 90 ppb; and September, 114 ppb); thallium (PMCL is 2 ppb)—wells 28AA27 (March, 2.08 ppb) and 28AA29 (February, 2.56); barium (PMCL is 2,000 ppb)—well 28AA30 (March, 4,490 ppb); chromium (PMCL is 30 ppb)—well 28AA30 (February, 630 ppb; and March, 1,190 ppb); and beryllium (PMCL is 4 ppb)—well 28AA30 (September, 6.3 ppb). Water from seven wells, three of which are upgradient of the landfill, contained organic compounds and/or selected trace elements exceeding PMCLs during the period February 1998 to September 1999 according to private consultants. Contaminants present in upgradient wells most likely were caused by chemical dispersion, leachate migration, incorrectly defined landfill area, or natural ground-water flow beneath the landfill.

Georgia↗

USGS2021

Precipitation-runoff processes in the Merced River Basin, Central California, with prospects for streamflow predictability, water years 1952–2013

The U.S. Geological Survey, in cooperation with the California Department of Water Resources (DWR), has constructed a new spatially detailed Precipitation-Runoff Modeling System (PRMS) model for the Merced River Basin, California, which is a tributary of the San Joaquin River in California. Operated through an Object User Interface (OUI) with Ensemble Streamflow Prediction (ESP) and daily climate distribution preprocessing functionality, the model is calibrated primarily to simulate (and eventually, forecast) year-to-year variations of inflows to Lake McClure during the critical April–July snowmelt season. The model is intended to become part of a suite of methods used by DWR for estimating daily streamflow from the Merced River Basin, especially during the snowmelt season. This study describes the results of the application of an analysis tool that simulates responses to climate and land-use variations at a higher spatial resolution than previously available to DWR. A geographic information system was used to delineate the model domain, that is, areas draining to a single outlet at U.S. Geological Survey streamflow-gaging station 11270900, Merced River below Merced Falls Dam, near Snell, CA (also known as California Data Exchange Center station MRC), and subdrainage areas, including four draining to internal gages used as calibration targets. Using this delineation, three contiguous subbasins were recognized and, along with the model domain and nested calibration targets, are the simulation units evaluated in this report. An auto-calibration tool, LUCA (Let Us CAlibrate), was used for each calibration node, from headwaters to basin outlet, and then parameters were manually adjusted to complete the calibration. The main objective was to match April–July snowmelt seasonal discharge values of simulated streamflow to observed (measured or reconstructed) discharge values. Calibration or validation periods used site-specific streamflows—mostly from October 1, 1988, through September 30, 2013—but differed according to the period-of-record available for the measurements collected at internal gages or reconstructed flows for the single outlet. The accuracy of the Merced PRMS streamflow simulations varied seasonally, as compared to observed values. Based on statistical results, the Merced PRMS model satisfactorily simulated snowmelt seasonal streamflows. April–July calibrations for all areas had small negative bias (not greater than 7 percent) and low relative error (less than 8 percent). Less satisfactory performance for other seasons was attributed to several factors: (1) high uncertainty in low or zero flows in summer and fall, (2) lack of accounting for basin withdrawals and anthropogenic water use, (3) unavailability and (or) inaccuracy of observed (measured) meteorological input data, and (4) uncertainty in reconstructed streamflow data. With some additional refinement, the Merced PRMS model may be used for forecasting seasonal and longer-term streamflow variations; evaluating forecasted and past climate and land cover changes; providing water-resource managers with a consistent and documented method for estimating streamflow at ungaged sites within the basin; and aiding environmental studies, hydraulic design, water management, and water-quality projects in the Merced River Basin.

California↗

USGS2003

Ferricrete, manganocrete, and bog iron occurrences with selected sedge bogs and active iron bogs and springs in the upper Animas River watershed, San Juan County, Colorado

During 1996 to 2000, the Bureau of Land Management, National Park Service, Environmental Protection Agency, United States Department of Agriculture (USDA) Forest Service, and the U.S. Geological Survey (USGS) developed a coordinated strategy to (1) study the environmental effects of historical mining on Federal lands, and (2) remediate contaminated sites that have the greatest impact on water quality and ecosystem health. This dataset provides information that contributes to these overall objectives and is part of the USGS Abandoned Mine Lands Initiative. Data presented here represent ferricrete occurrences and selected iron bogs and springs in the upper Animas River watershed in San Juan County near Silverton, Colorado. Ferricretes (stratified iron and manganese oxyhydroxide-cemented sedimentary deposits) are one indicator of the geochemical baseline conditions as well as the effect that weathering of mineralized rocks had on water quality in the Animas River watershed prior to mining. Logs and wood fragments preserved in several ferricretes in the upper Animas River watershed, collected primarily along streams, yield radiocarbon ages of modern to 9,580 years B.P. (P.L. Verplanck, D.B. Yager, and S.E. Church, work in progress). The presence of ferricrete deposits along the current stream courses indicates that climate and physiography of the Animas River watershed have been relatively constant throughout the Holocene and that weathering processes have been ongoing for thousands of years prior to historical mining activities. Thus, by knowing where ferricrete is preserved in the watershed today, land-management agencies have an indication of (1) where metal precipitation from weathering of altered rocks has occurred in the past, and (2) where this process is ongoing and may confound remediation efforts. These data are included as two coverages-a ferricrete coverage and a bogs and springs coverage. The coverages are included in ArcInfo shapefile and ArcInfo interchange file format.

Colorado↗

USGS2007

Chinook salmon use of spawning patches: Relative roles of habitat quality, size, and connectivity

Declines in many native fish populations have led to reassessments of management goals and shifted priorities from consumptive uses to species preservation. As management has shifted, relevant environmental characteristics have evolved from traditional metrics that described local habitat quality to characterizations of habitat size and connectivity. Despite the implications this shift has for how habitats may be prioritized for conservation, it has been rare to assess the relative importance of these habitat components. We used an information-theoretic approach to select the best models from sets of logistic regressions that linked habitat quality, size, and connectivity to the occurrence of chinook salmon (Oncorhynchus tshawytscha) nests. Spawning distributions were censused annually from 1995 to 2004, and data were complemented with field measurements that described habitat quality in 43 suitable spawning patches across a stream network that drained 1150 km 2 in central Idaho. Results indicated that the most plausible models were dominated by measures of habitat size and connectivity, whereas habitat quality was of minor importance. Connectivity was the strongest predictor of nest occurrence, but connectivity interacted with habitat size, which became relatively more important when populations were reduced. Comparison of observed nest distributions to null model predictions confirmed that the habitat size association was driven by a biological mechanism when populations were small, but this association may have been an area-related sampling artifact at higher abundances. The implications for habitat management are that the size and connectivity of existing habitat networks should be maintained whenever possible. In situations where habitat restoration is occurring, expansion of existing areas or creation of new habitats in key areas that increase connectivity may be beneficial. Information about habitat size and connectivity also could be used to strategically prioritize areas for improvement of local habitat quality, with areas not meeting minimum thresholds being deemed inappropriate for pursuit of restoration activities. ?? 2007 by the Ecological Society of America.

Ecological Applications↗

USGS2011

Trace element, semivolatile organic, and chlorinated organic compound concentrations in bed sediments of selected streams at Fort Gordon, Georgia, February-April 2010

A spatial survey of streams was conducted from February to April 2010 to assess the concentrations of major ions, selected trace elements, semivolatile organic compounds, organochlorine pesticides, and polychlorinated biphenyls associated with the bed sediments of surface waters at Fort Gordon military installation near Augusta, Georgia. This investigation expanded a previous study conducted in May 1998 by the U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, that evaluated the streambed sediment quality of selected surface waters at Fort Gordon. The data presented in this report are intended to help evaluate bed sediment quality in relation to guidelines for the protection of aquatic life, and identify temporal trends in trace elements and semivolatile organic compound concentrations at streambed sites previously sampled. Concentrations of 34 major ions and trace elements and 102 semivolatile organic, organochlorine pesticide, and polychlorinated biphenyl compounds were determined in the fine-grained fraction of bed sediment samples collected from 13 of the original 29 sites in the previous study, and 22 additional sites at Fort Gordon. Three of the sites were considered reference sites as they were presumed to be located away from potential sources of contaminants and were selected to represent surface waters flowing onto the fort, and the remaining 32 nonreference sites were presumed to be located within the contamination area at the fort. Temporal trends in trace elements and semivolatile organic compound concentrations also were evaluated at 13 of the 32 nonreference sites to provide an assessment of the variability in the number of detections and concentrations of constituents in bed sediment associated with potential sources, accumulation, and attenuation processes. Major ion and trace element concentrations in fine-grained bed sediment samples from most nonreference sites exceeded concentrations in samples from reference sites at Fort Gordon. Bed sediments from one of the nonreference sites sampled contained the highest concentrations of copper and lead with elevated levels of zinc and chromium relative to reference sites. The percentage change of major ions, trace elements, and total organic carbon that had been detected at sites previously sampled in May 1998 and current bed sediment sites ranged from -4 to 8 percent with an average percentage change of less than 1 percent. Concentrations of major ions and trace elements in bed sediments exceeded probable effect levels for aquatic life (based on the amphipod Hyalella azteca) established by the U.S. Environmental Protection Agency at 46 and 69 percent of the current and previously sampled locations, respectively. The greatest frequency of exceedances for major ions and trace elements in bed sediments was observed for lead. Concentrations of semivolatile organic compounds, organochlorine pesticides, and polychlorinated biphenyls were detected in bed sediment samples at 94 percent of the sites currently sampled. Detections of these organic compounds were reported with greater frequency in bed sediments at upstream sampling locations, when compared to downstream locations. The greatest number of detections of these compounds was reported for bed sediment samples collected from two creeks above a lake. The percentage change of semivolatile organic compounds detected at previously sampled and current bed sediment sites ranged from -68 to 100 percent with the greatest percentage increase reported for one of the creeks above the lake. Concentrations of semivolatile organic compounds and polychlorinated biphenyls in bed sediments exceeded aquatic life criteria established by the U.S. Environmental Protection Agency at three sites. Contaminant compounds exceeding aquatic life criteria included fluoranthene, phenanthrene, anthracene, benzo(a)anthracene

Georgia↗

USGS2011

Managing and learning with multiple models: Objectives and optimization algorithms

The quality of environmental decisions should be gauged according to managers' objectives. Management objectives generally seek to maximize quantifiable measures of system benefit, for instance population growth rate. Reaching these goals often requires a certain degree of learning about the system. Learning can occur by using management action in combination with a monitoring system. Furthermore, actions can be chosen strategically to obtain specific kinds of information. Formal decision making tools can choose actions to favor such learning in two ways: implicitly via the optimization algorithm that is used when there is a management objective (for instance, when using adaptive management), or explicitly by quantifying knowledge and using it as the fundamental project objective, an approach new to conservation.This paper outlines three conservation project objectives - a pure management objective, a pure learning objective, and an objective that is a weighted mixture of these two. We use eight optimization algorithms to choose actions that meet project objectives and illustrate them in a simulated conservation project. The algorithms provide a taxonomy of decision making tools in conservation management when there is uncertainty surrounding competing models of system function. The algorithms build upon each other such that their differences are highlighted and practitioners may see where their decision making tools can be improved. ?? 2010 Elsevier Ltd.

Biological Conservation↗

USGS1996

Evaluation and modification of five techniques for estimating stormwater runoff for watersheds in west-central Florida

Several traditional techniques have been used for estimating stormwater runoff from ungaged watersheds. Applying these techniques to watersheds in west-central Florida requires that some of the empirical relations be extrapolated beyond tested ranges. As a result, there is uncertainty as to the accuracy of these estimates. Sixty-six storms occurring in 15 west-central Florida watersheds were initially modeled using the Rational Method, the U.S. Geological Survey Regional Regression Equations, the Natural Resources Conservation Service TR-20 model, the U.S. Army Corps of Engineers HEC-1 model, and the U.S. Environmental Protection Agency Storm Water Management Model. The techniques were applied according to the guidelines specified in the user manuals or standard engineering textbooks as though no field data were available and the selection of input parameters was not influenced by observed data. Computed estimates were compared with observed runoff to evaluate the accuracy of the techniques. One watershed was eliminated from further evaluation when it was determined that the area contributing runoff to the stream varies with the amount and intensity of rainfall. Therefore, further evaluation and modification of the input parameters were made for only 62 storms in 14 watersheds. Runoff ranged from 1.4 to 99.3 percent of rainfall. The average runoff for all watersheds included in this study was about 36 percent of rainfall. The average runoff for the urban, natural, and mixed land use watersheds was about 41, 27, and 29 percent of rainfall, respectively. Initial estimates of peak discharge using the Rational Method produced average watershed errors that ranged from an underestimation of 50.4 percent to an overestimation of 767 percent. The coefficient of runoff ranged from 0.20 to 0.60. Calibration of the technique produced average errors that ranged from an underestimation of 3.3 percent to an over estimation of 1.5 percent. The average calibrated coefficient of runoff for each watershed ranged from 0.02 to 0.72. The average values of the coefficient of runoff necessary to calibrate the urban, natural, and mixed land use watersheds were 0.39, 0.16, and 0.08, respectively. The U.S. Geological Survey regional regression equations for determining peak discharge produced errors that ranged from an underestimation of 87.3 percent to an overestimation of 1,140 percent. The regression equations for determining runoff volume produced errors that ranged from an underestimation of 95.6 percent to an overestimation of 324 percent. Regression equations developed from data used for this study produced errors that ranged between an underestimation of 82.8 percent and an overestimation of 328 percent for peak discharge and from an underestimation of 71.2 percent to an overestimation of 241 percent for runoff volume. Use of the equations developed for west-central Florida streams produced average errors for each type of watershed that were lower than errors associated with use of the U.S. Geological Survey regional equations. Initial estimates of peak discharges and runoff volumes using the Natural Resources Conservation Service TR-20 model, produced average errors of 44.6 and 42.7 percent, respectively, for all the watersheds. Curve numbers and times of concentration were adjusted to match estimated and observed peak discharges and runoff volumes. The average change in the curve number for all the watersheds was a decrease of 2.8 percent. The average change in the time of concentration was an increase of 59.2 percent. The shape of the input dimensionless unit hydrograph also had to be adjusted to match the shape and peak time of the estimated and observed flood hydrographs. Peak rate factors for the modified input dimensionless unit hydrographs ranged from 162 to 454. The mean errors for peak discharges and runoff volumes were reduced to 18.9 and 19.5 percent, respectively, using the average calibrated input parameters for each watershed. Initial estimates of peak discharges and runoff volumes using the U.S. Army Corp of Engineers Hydrologic Engineering Center-1 model, produced average errors of 105 and 26.8 percent respectively, for all the watersheds. Curve numbers and lag times were adjusted to match estimated and observed peak discharges and runoff volumes. The average change in the curve number for all the watersheds was a decrease of 2.5 percent. The average change in the lag time was an increase of 169 percent. The mean errors for peak discharges and runoff volumes were reduced to 5.8 and 1.4 percent, respectively, using the average calibrated input parameters for each watershed. The observed and estimated peak discharges and runoff volumes could be matched by adjusting curve numbers and lag time using the U.S. Army Corp of Engineers Hydrologic Engineering Center-1 model; however, the shape of the estimated flood hydrograph and timing of the peak could not be matched. The input dimensionless unit hydrograph must also be changed to increase the accuracy of the Hydrologic Engineering Center-1 model for watersheds in west-central Florida. The source code has to be modified and recompiled to enter different dimensionless unit hydrographs into the HEC-1 program. During application of the U.S. Environmental Protection Agency Storm Water Management Model, two separate infiltration methods were evaluated. Initial estimates of peak discharges and runoff volumes produced mean errors of 46.5 and 6.8 percent, respectively, for all watersheds using the Green-Ampt infiltration method, and 48.8 and 9.5 percent, respectively, using the Horton infiltration method. The mean errors were reduced to 18 and 0.3 percent for the Green-Ampt method and 20.9 and 7.2 percent for the Horton method using the average calibrated input parameters for each watershed. Estimates of peak discharges and runoff volumes were initially made for watersheds in west-central Florida using recommended procedures, then compared to observed peak discharges and runoff volumes. Subsequently, the procedures were modified to increase accuracy for this area. The same methods used during the study could be used in other parts of the world to evaluate the accuracy of standard methods for estimating stormwater runoff.

Florida↗

USGS2022

Modeling protected species distributions and habitats to inform siting and management of pioneering ocean industries: A case study for Gulf of Mexico aquaculture

Marine Spatial Planning (MSP) provides a process that uses spatial data and models to evaluate environmental, social, economic, cultural, and management trade-offs when siting (i.e., strategically locating) ocean industries. Aquaculture is the fastest-growing food sector in the world. The United States (U.S.) has substantial opportunity for offshore aquaculture development given the size of its exclusive economic zone, habitat diversity, and variety of candidate species for cultivation. However, promising aquaculture areas overlap many protected species habitats. Aquaculture siting surveys, construction, operations, and decommissioning can alter protected species habitat and behavior. Additionally, aquaculture-associated vessel activity, underwater noise, and physical interactions between protected species and farms can increase the risk of injury and mortality. In 2020, the U.S. Gulf of Mexico was identified as one of the first regions to be evaluated for offshore aquaculture opportunities as directed by a Presidential Executive Order. We developed a transparent and repeatable method to identify aquaculture opportunity areas (AOAs) with the least conflict with protected species. First, we developed a generalized scoring approach for protected species that captures their vulnerability to adverse effects from anthropogenic activities using conservation status and demographic information. Next, we applied this approach to data layers for eight species listed under the Endangered Species Act, including five species of sea turtles, Rice’s whale, smalltooth sawfish, and giant manta ray. Next, we evaluated four methods for mathematically combining scores (i.e., Arithmetic mean, Geometric mean, Product, Lowest Scoring layer) to generate a combined protected species data layer. The Product approach provided the most logical ordering of, and the greatest contrast in, site suitability scores. Finally, we integrated the combined protected species data layer into a multi-criteria decision-making modeling framework for MSP. This process identified AOAs with reduced potential for protected species conflict. These modeling methods are transferable to other regions, to other sensitive or protected species, and for spatial planning for other ocean-uses.

PLoS ONE↗

USGS2020

A weight-of-evidence approach for defining thermal sensitivity in a federally endangered species

1. Managing for threatened and endangered species under changing environmental conditions is a challenge faced by resource managers worldwide. Lack of basic knowledge of the biology and habitat requirements of these species can contribute to this difficulty, but is confounded by the limitations of working with rare (i.e. few individuals) species or unrefined methods for evaluating stress. 2. A weight of evidence approach was used to evaluate the thermal biology of the federally endangered dwarf wedgemussel ( Alasmidonta heterodon ), utilizing cumulative results from multiple experimental assessments, co-occurring species, and their host fish to begin defining thermal limits and optimal conditions for the species. 3. Results suggest that dwarf wedgemussel and its host fish are thermally sensitive species compared to other Atlantic-slope mussels, with lower critical thermal maximum and selection of reduced temperatures during choice experiments. 4. Physiological studies resulted in lack of statistical significance primarily due to low power which was a function of sample size, one unavoidable problem when studying rare species. Given these limitations, thermal choice and CTM may be more useful endpoints than physiological processes such as clearance and respiration rates when dealing with sample size limitations. 5. These results suggest that management strategies that avoid exposing dwarf wedgemussel and its thermally sensitive host fish to extreme temperatures could be important for species conservation.

New Jersey, Pennsylvania↗

USGS2025

Streamflow as a stressor: Disentangling hydrology and water quality impacts to characterize flow-ecology relationships for two stream assemblages across two southeastern landscapes

Disassociating the independent effects of flow and water quality on the ecology of flowing waters is an overarching goal in water resource science needed to improve the efficacy of watershed management. However, the interrelatedness of these gradients and their subsequent alteration due to land use change has constrained progress made on this front. The objective of this study was to use benthic macroinvertebrate and fish assemblage data to characterize flow-ecology relationships that were unchanged by water quality impacts across two southeastern landscapes in the USA to help detect ecological change driven by flow alteration. General linear latent models were used to identify taxa that were responsive to high or low flow metrics and water quality gradients. Bayesian hierarchical generalized additive models were then developed using these indicator taxa and three biological metrics to identify flow-specific relationships that were unaffected by water quality impacts. Three low flow-specific relationships were identified, illustrating how potential agricultural or urban impacts to hydrology reduced stream biological health. Importantly, flow-ecology relationships developed using indicator taxa in this study effectively captured hydrology-specific impacts while biological metrics typical of state monitoring and assessment programs did not. Therefore, developing flow-specific biological metrics is a critical step when developing management strategies targeting flow alteration. Implementing standardized frameworks such as the one characterized here can limit contradictory findings and improve streamflow enhancement and restoration project efficacy. These low flow-specific relationships will enhance managers' capacity to develop environmental flow standards, monitor their success, and better understand urban and agricultural impacts on stream assemblages.

Alabama↗

USGS2024

Wood you believe it? Experimental addition of nonnative wood enhances instream habitat for native dryland fishes

Flow alteration and riparian vegetation encroachment are causing habitat simplification with severe consequences for native fishes. To assess the effectiveness of enhancing simplified habitat in a large dryland river, we experimentally added invasive wood at 19 paired treatment and reference (no wood added) subreaches (50–100 m) within the main channel of the San Juan River. Using a before-after-control-impact design, we sampled fishes and macroinvertebrates, and quantified habitat complexity. After wood addition, total native fish densities were 2.2× higher in treatments compared with references, whereas total nonnative fish densities exhibited no response. Macroinvertebrate densities were 6.8× higher, and habitat complexity increased in treatments. Counts of geomorphic features in treatments increased from 1 to a maximum of 11 following wood addition, while the number of features in references remained unchanged. Wood addition has potential to instigate natural riverine processes, ultimately enhancing native fish habitat by increasing macroinvertebrate densities and habitat complexity in dryland rivers. Water overallocation and increasing aridity will continue to challenge efforts to improve habitat conditions with environmental flows alone, and managers might consider integrating non-flow alternatives like addition of abundant, invasive wood to reduce habitat simplification.

New Mexico, Utah↗

USGS2019

Trophic plasticity and the invasion of a renowned piscivore: A diet synthesis of northern pike (Esox lucius) from the native and introduced ranges in Alaska, U.S.A.

The invasion of non-native fishes is a leading cause of extinction and imperilment of native freshwater fishes. Evidence suggests that introduced species with generalist diets have the potential for greatest impacts through competition and predation even though populations are often comprised of specialist individuals. The northern pike (Esox lucius), a predatory fish, has been widely introduced outside its native range for recreational fishing purposes, especially in western North America, and it has been implicated in declines and extirpations of native fishes. We synthesized over 2,900 individual northern pike diet records across 31 waterbodies from the native and introduced ranges in Alaska to quantify the extent of diet specialization and generalization relative to freshwater prey communities. To control for effects of ontogenetic diet shifts, we separately analyzed major size classes of northern pike and inferred and visualized trophic plasticity from Prey-Specific Abundance indices and ordination. Diet generalization was common in northern pike among waterbodies and usually consisted of individuals consuming macroinvertebrates. However, when available, individual northern pike diets showed specialization on fishes, amphibians, small mammals, and dragonflies. The reliance on macroinvertebrate prey by northern pike from small, isolated lakes in the native and invasive ranges suggests that dietary plasticity facilitates persistence of these predators in the absence of preferred fish prey. Broadly, this synthesis supports the hypothesis that trophic plasticity and diet generalization widely occur among invasive and native populations of northern pike which is likely to enhance the probability of introduction success, exacerbate their environmental impacts, and complicate management of this potentially invasive freshwater predator.

Alaska↗