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Documentation for the U.S. Geological Survey Public-Supply Database (PSDB): A database of permitted public-supply wells, surface-water intakes, and systems in the United States

The U.S. Geological Survey (USGS) has developed a database containing information about wells, surface-water intakes, and distribution systems that are part of public water systems across the United States, its territories, and possessions. Programs of the USGS such as the National Water Census, the National Water Use Information Program, and the National Water-Quality Assessment Program all require a complete and current inventory of public water systems, the sources of water used by those systems, and the size of populations served by the systems across the Nation. Although the U.S. Environmental Protection Agency’s Safe Drinking Water Information System (SDWIS) database already exists as the primary national Federal database for information on public water systems, the Public-Supply Database (PSDB) was developed to add value to SDWIS data with enhanced location and ancillary information, and to provide links to other databases, including the USGS’s National Water Information System (NWIS) database. The purpose of this report is to document the PSDB and explain the methods used to populate and update the data from the SDWIS, State datasets, and map and geospatial imagery. This report describes 3 data tables and 11 domain tables, including field contents, data sources, and relations between tables. Although the PSDB database is not available to the general public, this information should be useful for others who are developing other database systems to store and analyze public-supply system and facility data.

Open-File Report↗

Environmental, morphological, and molecular data reveal a new species of freshwater mussel, Strophitus howellsi, endemic to the Edwards Plateau in Texas

Freshwater mussels are considered the most imperiled group of organisms in North America and systematics research has played an integral role in the development and implementation of their conservation. Despite the importance of systematics in conservation planning, the evolutionary relationships between many mussel taxa remain poorly explored, clearly illustrated by Strophitus undulatus . This species is wide-ranging, occurring in streams across the United States and Canada with a disjunct population in the Colorado River drainage in central Texas. The widespread distribution of S. undulatus , as well as high intraspecific morphological variation, has led previous authors to doubt the taxon is representative of a single species. In this study, we set out to investigate species boundaries in S. undulatus by integrating environmental, molecular, and morphological datasets. Molecular and morphological data supported S. undulatus from the Colorado River as distinct, which was supplemented by a species distribution modeling approach, suggesting potential adaptation to Edwards Plateau streams has contributed to speciation. Given our findings, we formally describe a new species of freshwater mussel, Strophitus howellsi , endemic to streams along the Edwards Plateau in the Colorado River drainage. A conservation assessment of S. howellsi suggests the species is extremely rare within a highly restricted distribution and may warrant future recovery actions. Our findings build on a growing body of literature highlighting aquatic endemism along the Edwards Plateau and have significant conservation implications for freshwater mussels in Texas.

Conservation Genetics↗

Outside the box: Working with wildlife in biocontainment

Research with captive wildlife in Animal Biosafety Level 2 (ABSL2) and 3 (ABSL3) facilities is becoming increasingly necessary as emerging and re-emerging diseases involving wildlife have increasing impacts on human, animal, and environmental health. Utilizing wildlife species in a research facility often requires outside the box thinking with specialized knowledge, practices, facilities, and equipment. The USGS National Wildlife Health Center (NWHC) houses an ABSL3 facility dedicated to understanding wildlife diseases and developing tools to mitigate their impacts on animal and human health. This review presents considerations for utilizing captive wildlife for infectious disease studies, including, husbandry, animal welfare, veterinary care, and biosafety. Examples are drawn from primary literature review and collective 40-year experience of the NWHC. Working with wildlife in ABSL2 and ABSL3 facilities differs from laboratory animals in that typical laboratory housing systems, husbandry practices, and biosafety practices are not designed for work with wildlife. This requires thoughtful adaptation of standard equipment and practices, invention of customized solutions and development of appropriate enrichment plans using the natural history of the species and the microbiological characteristics of introduced and native pathogens. Ultimately, this task requires critical risk assessment, understanding of the physical and psychological needs of diverse species, creativity, innovation, and flexibility. Finally, continual reassessment and improvement are imperative in this constantly changing specialty area of infectious disease and environmental hazard research.

ILAR Journal↗

Influence of basin- and local-scale environmental conditions on nearshore production in the northeast Pacific Ocean

Nearshore marine habitats are productive and vulnerable owing to their connections to pelagic and terrestrial landscapes. To understand how ocean basin- and local-scale conditions may influence nearshore species, we developed an annual index of nearshore production (spanning the period 1972–2010) from growth increments recorded in otoliths of representative pelagic-feeding (Black Rockfish Sebastes melanops ) and benthic-feeding (Kelp Greenling Hexagrammos decagrammus ) nearshore-resident fishes at nine sites in the California Current and Alaska Coastal Current systems. We explored the influence of basin- and local-scale conditions across all seasons at lags of up to 2 years to represent changes in prey quantity (1- or 2-year time lags) and quality (within-year relationships). Relationships linking fish growth to basin-scale (Pacific Decadal Oscillation, North Pacific Gyre Oscillation, and multivariate El Niño–Southern Oscillation index) and local-scale (sea surface temperature, sea surface height anomalies, upwelling index, photosynthetically active radiation, and freshwater discharge) environmental conditions varied by species and current system. Growth of Black Rockfish increased with cool basin-scale conditions in the California Current and warm local-scale conditions in the Alaska Coastal Current, consistent with existing hypotheses linking climate to pelagic production on continental shelves in the respective regions. Relationships for Kelp Greenlings in the California Current were complex, with faster growth related to within-year warm conditions and lagged-year cool conditions. These opposing, lag-dependent relationships may reflect differences in conditions that promote quantity versus quality of benthic invertebrate prey in the California Current. Thus, we hypothesize that benthic production is maximized by alternating cool and warm years, as benthic invertebrate recruitment is food limited during warm years while growth is temperature limited by cool years in the California Current. On the other hand, Kelp Greenlings grew faster during and subsequent to warm conditions at basin and local scales in the Alaska Coastal Current.

Marine and Coastal Fisheries: Dynamics, Management↗

Oyster model inventory: Identifying critical data and modeling approaches to support restoration of oyster reefs in coastal U.S. Gulf of Mexico waters

Executive Summary Along the coast of the U.S. Gulf of Mexico, the eastern oyster ( Crassostrea virginica ) plays important ecological and economic roles. Commercial landings from this region account for more than 50 percent of all U.S. landings; these oyster reefs also provide varied ecosystem services, including nursery habitat for many fish and macroinvertebrate species, shoreline protection, and water-quality maintenance. Declining trends in both total oyster production and functional reef area across this region have spurred investment in restoration of oyster resources, with specific calls for restoration projects to develop a network of reefs and identify broodstock and sanctuary reef restoration sites. Decision making related to restoration and establishment of a network of oyster reefs in the Gulf of Mexico requires information on both the environment and the effects of the environment on the oyster life cycle (including larval movement, survival, oyster recruitment, reproduction, growth, and mortality). Here, we examined the current state of data and model development in this region with the goal of providing an overview of oyster modeling approaches and an inventory of available data and existing oyster models. This report is meant to provide an overview to managers for understanding existing efforts and identify a path forward to most efficiently inform oyster resource management and restoration planning in moving from a single reef management approach to a reef network management approach. Numerous models related to some aspect of the oyster life cycle have been built, calibrated, and validated for various Gulf of Mexico estuaries over the last few decades (over 30 models identified). These models, which could inform site restoration, can be classified into four approaches: (1) oyster Habitat Suitability Index (HSI) models; (2) larval transport models; (3) on-reef oyster models that may include oyster growth, mortality and reproduction, and substrate persistence; and (4) coupled larval transport on-reef metapopulation models that simulate the entire oyster life cycle. The data requirements, model complexity and assumptions, and transferability vary by approach. Specifically, some approaches may offer greater accessibility, flexibility, and transferability spatially or temporally, with minimal data input, but only provide broad information to support site selection. In contrast, other approaches may require significant site-specific data for their construction and validation but may provide more accurate and location-specific data to support site selection for broodstock reefs. Regardless of modeling approach used, data on environmental drivers, such as salinity, water temperature, or water flow impacting oyster metabolism and movement, are required at appropriate spatial and temporal scales. While numerous data collection platforms, environmental models, and research products exist within Gulf of Mexico estuaries to provide important environmental data to use as drivers in the oyster models, significant variability in temporal and spatial coverage of the data, and variation in the availability of future condition models, exists across estuaries. This variation influences the spatial and temporal scales at which oyster models may be developed and impacts the calibration and validation of the oyster models within a given estuary, affecting its potential ability to address specific management or restoration questions. While multiple modeling approaches exist for informing site selection of broodstock or sanctuary oyster reefs, the development, calibration, and validation of a single modeling platform presents the most efficient, transferable, and useful tool for managers across the Gulf of Mexico. The development of a single modeling platform would involve using standardized input variables, governing equations, and assumptions for the modeled oyster processes and outputs, and for standardized calibration and validation procedures that could be applied within each estuary. The differences among estuary applications would require substituting only estuary-specific environmental data, and calibrating and validating the modeling approach with local oyster data. Two modeling approaches likely to be useful include (1) development of a general geospatial HSI modeling framework that could be applied consistently across estuaries and (2) a mechanistic coupled larval transport on-reef metapopulation model requiring only estuarine specific calibration and hydrodynamic models. Both approaches benefit from existing work across multiple Gulf of Mexico estuaries and could provide valuable support for oyster restoration, but may differ in their ability to address specific questions related to oyster restoration. HSI models specifically guide restoration practitioners in determining suitable habitat based on available data. The HSI approach, while currently more widely used and accessible, requires more development of larval suitability and larval input and output components in order to inform reef connectivity. A metapopulation approach considering the full oyster life cycle that simulates both on-reef oyster growth, mortality, reproduction, substrate persistence, and larval transport (ideally with larval growth and mortality) would provide the greatest detail and level of understanding but requires significant up-front investment. The larval oyster model and on-reef oyster model are usually developed independently for systems, although the two approaches can be coupled to represent the entire oyster life cycle in order to characterize and assess a reef metapopulation. This approach may be less accessible and much more data-intensive, however, and it requires some expertise to run and apply to inform oyster resource management. Ultimately, the development of single modeling platforms for each of these approaches would provide flexible tools applicable across all Gulf of Mexico oyster supporting estuaries. By using a single platform for model development, testing, calibrating and validating, and evaluation of modeled future scenarios, oyster restoration scientists and managers would not only be able to examine different scenario outcomes within a single estuary, but could also have comparable modeled results to evaluate potential outcomes, across estuaries and regions, that are not confounded by varying modeled data inputs, governing equations, assumptions, or user judgement.

Alabama, Florida, Louisiana, Mississippi, Texas↗

Quaternary vegetation and climate change in the western United States: Developments, perspectives, and prospects

This chapter explores the strengths and shortcomings of the major sources of data on Quaternary vegetation and climate change and discusses the use of models as a means to explore past and potential future environmental changes. The flora and major vegetation types of the western United States are present for several million years. Ongoing changes in atmospheric chemistry , climate, and human activities may lead to major vegetation changes over the coming decades to centuries. The combination of observations from the paleoenvironmental record, modern ecological studies, and modeling now permit assessments of the magnitude of potential future changes in the context of natural variability. They also provide opportunities for hypothesis testing and identification of the processes driving past changes in vegetation and climate. Understanding the dynamics of paleoenvironmental change can contribute to current conservation and natural resource management efforts and will help conservation and natural resource managers anticipate the potential rate, magnitude, and complexity of future vegetation change.

western United States↗

Cell proliferation detected with flow cytometric cell cycle analysis and immunohistochemical detection of Proliferating Cell Nuclear Antigen (PCNA) from somatic tissues of Eastern Oysters, Crassostrea virginica

Two novel biomarker of response assays were developed and compared for use with bivalves. Bivalve mollusks are often used as bioindicators to monitor contaminant body burdens and are employed globally in pollution monitoring and as sentinels of environmental quality. The prevalence of proliferating cells in tissues of the eastern oyster, Crassostrea virginica , (n = 10) was investigated by using immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and by flow cytometric analysis of DNA in cell cycle phases. The PCNA protein is highly conserved and central to DNA synthesis in dividing cells. This protein was detected by using a commercial antibody in the histological staining of gills, mantle, digestive gland, stomach, and labial palps. Cells obtained from these same organs and from the hearts of the oysters were used for flow cytometry (FCM). The proportions of nuclei in the S plus G2/M and G2/M fractions were compared with percentages of PCNA-positive cells scored through microscopy. Proliferation responses generated by microscopy and FCM (S plus G2/M) were equal for digestive gland, gills, stomach, and mantle. The proliferation response in labial palps was significantly higher by PCNA microscopy than by DNA FCM (S plus G2/M). For PCNA microscopy results, a significantly higher proliferation response was noted both for labial palps as compared to gills and mantle and for stomach and digestive gland as compared to gills (P < 0.005). For DNA FCM results, the percentages of proliferating cells in G2M fractions were significantly higher for labial palps and heart when compared to gills, mantle, and digestive gland. By FCM (S plus G2M), the percentages of proliferating cells followed a similar trend, although no significant differences were found between organs. The choice of a relatively highly proliferative tissue, such as labial palps as determined by this study, has utility for developing a cell line, for examining proliferation as a biomarker due to stressor impacts in feral oysters, and for detecting impacts of compounds on proliferative mechanisms.

Environmental Bioindicators↗

Environmental drivers and spatial patterns of antibiotic-resistant, enteric coliforms across a forest–urban riverscape

Antibiotic resistant bacteria are prevalent environmental contaminants in freshwaters, and antibiotic resistance genes circulate throughout the urban water cycle. The increase of antibiotic resistant pathogens threatens public health through direct and indirect exposure, and natural resource managers need information on the spatial patterns of antibiotic resistant bacteria and environmental factors associated with their distribution to improve water quality monitoring and to better assess human, animal, and environmental health risks. We collected water and epilithic biofilm samples and measured physicochemical environmental variables at 29 sites distributed longitudinally in the Green-Duwamish River basin, Washington, USA. We characterized catchment-wide patterns of gram-negative fecal indicator bacteria and hypothesized that the presence of antibiotic resistance would be associated with environmental heterogeneity, bacterial primary ecology, stream compartment, and stream type. Antibiotic resistance was determined by microbial growth on selective media supplemented with 3 different antibiotics (ampicillin, chloramphenicol, or tetracycline). Phenotypic antibiotic resistance was positively associated with disturbance, but resistance to at least 1 antibiotic was also detected in undeveloped river segments, with an 83% overall detection rate (i.e., 24 out of 29 sites, 17 in the mainstem and 7 in tributaries). The most probable number of Escherichia coli was associated with higher levels of antibiotic resistance of non- E. coli coliforms across the basin (ρ = 0.38, p < 0.01) but was not associated with antibiotic resistance of E. coli . Phenotypic resistance was highest among non- E. coli coliforms in the water column of tributaries draining moderately to extensively developed subcatchments. Generalized linear mixed-effects model results showed that 18% of the variance in presence of antibiotic resistance was explained by the fixed effects (summed CV across environmental variables, stream type, primary ecology, and stream compartment), and when a spatial random effect was included, the model explained 27% of the variance. Our study provides new evidence that environmental factors and bacterial primary ecology are important underlying factors associated with spatial patterns of antibiotic resistant enteric coliforms. We used macroecological concepts and a riverscape approach to characterize the distribution of antibiotic resistance with methods applicable to municipalities.

Freshwater Science↗

No evidence for cottonwood forest decline along a flow-augmented western U.S. river

In contrast to many other arid region rivers, streamflow in the South Platte River is heavily augmented by trans-basin water imports and irrigation return flows. Hydrological changes began in the 1880s, resulting in channel narrowing and the development of a continuous Populus-Salix forest by the mid-twentieth century. We assessed the composition, structure and regeneration status of the riparian forest and identified environmental variables affecting annual Populus deltoides tree growth. We sampled forest structure at four sites in 2015, and conducted dendroecological analysis at seven additional sites in 2019. The riparian forest was dominated by P. deltoides , which occurred at all sites, comprising 79% of total tree basal area and 62% of total tree density. Age structure data indicated ongoing though episodic recruitment of P. deltoides , at least over the past ~130 years. We tested 14 linear mixed effects models to describe the effect of climate and streamflow on individual tree growth (modeled as the log of BAI, n = 237 trees). The most parsimonious model selected with AICc explained 28.6% of BAI variability, and included hydrology and climate factors during the growing season (i.e., June–August streamflow, June–July PDSI), some aspects of off-season (i.e., previous November and March) streamflow, along with tree age and study site effects. The riparian forest developed in response to, and has been maintained by, current climate conditions and water management regimes. It may be negatively affected by future climate change and increased urban water demand in the basin.

Colorado↗

An integrated analysis for estimation of survival, growth, and movement of unmarked juvenile anadromous fish

Managers invest substantial resources to promote recovery of declining anadromous fish stocks. Recovery strategies are manifold and often include management actions intended to stimulate somatic growth, increase in-river survival, and motivate juvenile outmigration during favorable environmental conditions. Evaluating the efficacy of these management actions is difficult, however, because monitoring data that explicitly track individuals from egg deposition to juvenile outmigration are typically lacking. We developed an integrated population model that links two different and often collected types of anadromous fish monitoring data: spawning ground surveys and rotary screw trap juvenile catch data. The integrated model accounts for incomplete detection and uses the two sources of data to estimate juvenile demographic parameters in a multistate framework. We evaluated the model's performance using simulated data under a range of conditions typically encountered in similar surveys. Simulation results indicated that the model estimated juvenile survival, growth, and movement with no-to-minimal bias (i.e., ≥ 50 % of simulations ± 0–0.05). As an example case study, we fit the model to empirical fall-run Chinook Salmon ( Oncorhynchus tshawytscha ) monitoring data collected in California's Central Valley, U.S.A. In doing so, we evaluated the influence of environmental conditions (e.g., discharge, water temperature) and habitat availability on juvenile demographic rates. We demonstrated that through our integrated approach we could estimate state transition probabilities that are typically inestimable for naturally produced, unmarked juvenile fish when using traditional statistical approaches to analyze these types of monitoring data. Furthermore, the structure of our model can serve as a useful foundation for decision-support models within adaptive management programs by directly linking management actions, decision-support-model predictions, and monitoring.

California↗

Accessibility of environmental data for sharing: The role of UX in large cyberinfrastructure projects

Incorporating user experience (UX) testing when creating research cyberinfrastructure is often overlooked, but if left too late, the cost of retrofitting is considerable, and the very clients the cyberinfrastructure was built to serve may be lost. Successfully integrating UX testing into the product development cycle can be difficult but rewarding. This paper describes how UX evaluations were incorporated over ten years of operation of DataONE ( www.dataone.org ), a multi-sector science research cyberinfrastructure project created to support the discovery, access, and sustainability of data about life on Earth and the environment that sustains it. The diverse stakeholders in DataONE include data creators and users such as researchers and government workers across the broad scope of the earth and environmental sciences as well as those who hold and manage data such as libraries and data repositories. Between 2009 and 2019 DataONE members designed and constructed data management tools and services to fulfill the DataONE objectives. To assist in achieving its goals, a participatory design approach was used by establishing several largely volunteer and stakeholder-representative working groups, including the Usability and Assessment Working Group. This Working Group conducted over forty UX evaluations to assess the usability of DataONE products and websites at various stages of the development process. In addition to improving the usability of DataONE products, the UX evaluations fostered community involvement by building trust and engagement with the products being developed. The DataONE UX experience yields several important lessons which will improve the success of other projects. It is our conclusion that UX testing should be a mandatory part of the design of any cyberinfrastructure project.

Ecological Informatics↗

Applications of a broad-spectrum tool for conservation and fisheries analysis: Aquatic gap analysis

Natural resources support all of our social and economic activities, as well as our biological existence. Humans have little control over most of the physical, biological, and sociological conditions dictating the status and capacity of natural resources in any particular area. However, the most rapid and threatening influences on natural resources typically are anthropogenic overuse and degradation. In addition, living natural resources (i.e., organisms) do not respect political boundaries, but are aware of their optimal habitat and environmental conditions. Most organisms have wider spatial ranges than the jurisdictional boundaries of environmental agencies that deal with them; even within those jurisdictions, information is patchy and disconnected. Planning and projecting effects of ecological management are difficult, because many organisms, habitat conditions, and interactions are involved. Conservation and responsible resource use involves wise management and manipulation of the aspects of the environment and biological communities that can be effectively changed. Tools and data sets that provide new insights and analysis capabilities can enhance the ability of resource managers to make wise decisions and plan effective, long-term management strategies. Aquatic gap analysis has been developed to provide those benefits. Gap analysis is more than just the assessment of the match or mis-match (i.e., gaps) between habitats of ecological value and areas with an appropriate level of environmental protection (e.g., refuges, parks, preserves), as the name suggests. Rather, a Gap Analysis project is a process which leads to an organized database of georeferenced information and previously available tools to examine conservation and other ecological issues; it provides a geographic analysis platform that serves as a foundation for aquatic ecological studies. This analytical tool box allows one to conduct assessments of all habitat elements within an area of interest. Aquatic gap analysis naturally focuses on aquatic habitats. The analytical tools are largely based on specification of the species-habitat relations for the system and organism group of interest (Morrison et al. 2003; McKenna et al. 2006; Steen et al. 2006; Sowa et al. 2007). The Great Lakes Regional Aquatic Gap Analysis (GLGap) project focuses primarily on lotic habitat of the U.S. Great Lakes drainage basin and associated states and has been developed to address fish and fisheries issues. These tools are unique because they allow us to address problems at a range of scales from the region to the stream segment and include the ability to predict species specific occurrence or abundance for most of the fish species in the study area. The results and types of questions that can be addressed provide better global understanding of the ecological context within which specific natural resources fit (e.g., neighboring environments and resources, and large and small scale processes). The geographic analysis platform consists of broad and flexible geospatial tools (and associated data) with many potential applications. The objectives of this article are to provide a brief overview of GLGap methods and analysis tools, and demonstrate conservation and planning applications of those data and tools. Although there are many potential applications, we will highlight just three: (1) support for the Eastern Brook Trout Joint Venture (EBTJV), (2) Aquatic Life classification in Wisconsin, and (3) an educational tool that makes use of Google Earth (use of trade or product names does not imply endorsement by the U.S. Government) and Internet accessibility.

Gap Analysis Bulletin↗

Genotype and elevation influence Spartina alterniflora colonization and growth in a created salt marsh

Colonization, growth, and clonal morphology differ with genotype and are influenced by elevation. Local adaptation of Spartina alterniflora to environmental conditions may lead to dominance by different suites of genotypes in different locations within a marsh. In a constructed marsh, we found reduced colonization in terms of density of clones with increasing distance from edge in a 200‐ha mudflat created in 1996; however, growth in diameter was not different among three 100‐m‐long zones that differed in distance from site edge. Distance from edge was confounded by elevation in this comparison of natural colonization. The rate of clonal expansion in diameter was 3.1 m/yr, and clonal growth was linear over the 28 mo of the study. The area dominated by S. alterniflora in the three distance zones increased concomitantly with clonal growth. However, the lower initial clonal densities and colonization by other plant species resulted in reduced overall dominance by S. alterniflora in the two more‐interior locations. Seedling recruitment was an important component of S. alterniflora colonization at all elevations and distances from edge two years after site creation. Seedlings were spatially very patchy and tended to occur near clones that probably produced them. A field experiment revealed that S. alterniflora height and total stem length varied with genotype, while stem density and flowering stem density did not. Differences between edge and center of clonal patches also occurred for some response variables, and there were also significant interactions with genotype. Differences between edge and center are interpreted as differences in clone morphology. Elevation differences over distances of a few meters influenced total stem length and flowering stem density but not other response variables. Clones that were larger in diameter also tended to have greater stem heights and total stem lengths. A number of plant morphological measures were found to vary significantly among the five genotypes and had broad‐sense heritabilities ranging up to 0.71. These results indicate that S. alterniflora populations developing on new substrata colonize broadly, but growth and reproduction vary with genotype and are influenced by changes in elevation (range: 11.8 cm), and probably other environmental factors, over relatively small distances. Differences in growth and clone morphology of different genets, and the frequent occurrence of seedlings throughout the site, underscore the importance of genetic variability in natural and created populations.

Louisiana↗

Lead toxicosis in tundra swans near a mining and smelting complex in northern Idaho

Die-offs of waterfowl have occurred in the Coeur d'Alene River system in northern Idaho since at least the early 1900's. We investigated causes of mortality and lead and cadmium contamination of 46 tundra swans ( Cygnus columbianus ) from 1987 to 1989; an additional 22 swans found dead in 1990 were not examined. We necropsied 43 of the 46 birds found from 1987 to 1989; 38 of these were from the Coeur d'Alene River system, which has been contaminated with mining and smelting wastes for a century, and the other 5 were from a nearby, relatively uncontaminated area. Of the 36 livers of swans from the contaminated area that were analyzed, 32 contained lethal levels of lead (6 to 40 μg/g, wet weight) and all birds exhibited several symptoms of lead poisoning, notably enlarged gall bladders containing viscous, dark-green bile. Only 13% of the lead-poisoned birds (10% when data were included from other studies of swans in the area) contained shot, compared to 95% of lead-poisoned swans in studies outside northern Idaho. Lead concentrations in blood samples from 16 apparently healthy swans (0.5 to 2.3 μg/g, and 4 lead-poisoned birds found moribund (1.3 to 9.6 μg/g) indicated that tundra swans accumulated high levels of lead from ingestion of sediment that contained up to 8,700 μg/g of lead and plants that contained up to 400 μg/g. The swans spend only a few weeks in the area staging during the spring migration. The five tundra swans from the uncontaminated area had low levels of lead and essentially no symptoms of lead poisoning. Based on the conventional standard of 0.5 μg/g in whole blood as an indicator of lead poisoning, all of the swans in the Coeur d'Alene River system were either lead-poisoned or at risk of developing plumbism.

Idaho↗

The solid waste dilemma

In 1976, the U.S. Congress enacted the Resource Conservation and Recovery Act (RCRA) to further address the problem of increasing industrial and municipal waste. The main objectives of RCRA were to responsibly manage hazardous and solid waste and to procure materials made from recovered wastes. To fulfill these objectives, four main programs of waste management were developed. These programs were defined under Subtitle C, the Hazardous Waste Program; Subtitle D, the Solid Waste Program; Subtitle I, the Underground Storage Tank Program; and Subtitle J, the Medical Waste Program. Subtitle D illustrates the solid waste dilemma occurring in the United States. Under this program, states are encouraged to develop and implement their own waste management plans. These plans include the promotion of recycling solid wastes and the closing and upgrading of all environmentally unsound dumps.

Natural Resources Research↗

Broad-scale impacts of an invasive native predator on a sensitive native prey species within the shifting avian community of the North American Great Basin

Human enterprise has modified ecosystem processes through direct and indirect alteration of native predators’ distribution and abundance. For example, human activities subsidize food, water, and shelter availability to generalist predators whose subsequent increased abundance impacts lower trophic-level prey species. The common raven (Corvus corax; hereafter, raven) is an avian predator, native to the northern hemisphere, that can become invasive when subsidized. Raven populations are increasing at unprecedented rates in many regions globally. Information regarding scale of impact and potential ecological thresholds is needed to guide conservation actions aimed at reducing adverse effects on sensitive prey. We conducted a multi-part analysis to investigate broad-scale variation in raven densities and impacts on nesting greater sage-grouse (Centrocercus urophasianus), an indicator species for sagebrush ecosystems in western North America. We estimated raven densities using 16,000 point surveys over 10 years within the Great Basin, USA, and examined associations with anthropogenic and environmental covariates. Average density was 0.54 ravens km-2 (95% CI: 0.42–0.70), with higher densities at lower relative elevations comprising increased agriculture and development. We then used a reduced dataset to estimate the effect of raven density on sage-grouse nest survival (nests = 737). We identified negative impacts to nesting sage-grouse, especially where raven density exceeded ~ 0.40 km-2, a potential ecological threshold. We mapped regions where elevated raven densities were predicted to depress sage-grouse population growth in the absence of compensatory demographic responses from other sage-grouse life-history stages, and found ~ 64% of sage-grouse breeding areas were adversely impacted by high raven density.

California, Idaho, Nevada, Oregon, Utah↗

Interaction Assessment: A modeling tool for predicting population dynamics from field data

Interaction Assessment (INTASS) is a field and analytic methodology for constructing population dynamics models. Because data collected in generating a model for one species comprise much of the information needed for other species, a small increase in effort can result in simultaneous expressions for the dynamics of multiple species. These expressions can be used to simulate whole community responses to environmental change, including management actions. Since publication of the most recent paper in this series, the INTASS methodology has undergone a large number of developments. These include the use of conceptual models to direct field and modeling efforts and incorporation of an information theoretic approach to model selection. We review these modifications and additions, applying them to a population of Sitka black-tailed deer ( Odocoilius hemionis ) in Alaska and to cheatgrass ( Bromus tectorum ) at the Desert Experimental Range in Utah. In both cases, useful information about the species&rsquo; ecology and population trends was ascertained. INTASS is portable across a wide range of taxa, habitats and management situations.

Ecological Modelling↗

Valuation of the flood attenuation ecosystem service in Difficult Run, VA, USA

Floodplains and riparian wetlands provide several ecosystem services that directly benefit people. We present a methodology for valuing the flood attenuation ecosystem service in Difficult Run, a suburban watershed with extensive natural floodplains in northern Virginia. High-resolution lidar-derived data were combined with GIS modeling techniques to produce estimates of flood inundation. We combined the modeled estimates with parcel-level property and primary economic data using a baseline and a counterfactual scenario to estimate the magnitude of flood attenuation and the associated value of the ecosystem service. Our framework brings new models and data to look at floodplains and an alternative land surface scenario in a way that has not previously been done. Annualized avoided property losses totaled $42,184 in the baseline scenario and $115,596 in the counterfactual scenario for the combined 200-, 100-, 50-, 20-, 10-, and 5-year flood events. We estimate the total annualized value of the flood attenuation ecosystem service in Difficult Run is $73,412, which is $77 per hectare of floodplain area and is consistent with similar valuation studies of floodplains. The framework presented here is not specific to the study area and could be deployed at larger spatial areas in other locations. Our methods may better inform land use decision making on the impacts of development in and surrounding floodplain areas.

Virginia↗

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