Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Environmental Development”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

USGS Western Coastal and Marine Geology Team

The Western Coastal and Marine Geology Team of the U.S. Geological Survey (USGS) studies the coasts of the western United States, including Alaska and Hawai‘i. Team scientists conduct research, monitor processes, and develop information about coastal and marine geologic hazards, environmental conditions, habitats, and energy and mineral resources. This information helps managers at all levels of government and in the private sector make informed decisions about the use and protection of national coastal and marine resources.

Fact Sheet↗

Mapping, monitoring, and modeling Western Gateway Community landscape dynamics

Federal public lands in the western United States are becoming increasingly surrounded by Gateway Communities. These communities are undergoing landscape change due to population growth, economic growth, and the resulting land-use development. Socioeconomic, demographic, and land-use changes in Gateway Communities are often perceived as threats to Federal land resources, natural amenities, cultural resources, and recreational opportunities. However, land-surface disturbances on Federal public lands, such as conventional and alternative energy development (which impact surrounding Gateway Communities), are also environmental and societal issues that Federal land and adjacent regional community planners need to consider in their long-range land-use planning.

Fact Sheet↗

Particle Size Characterization of Water-Elutriated Libby Amphibole 2000 and RTI International Amosite

This report presents data on particle characterization analyzed by scanning electron microscopy on Libby amphibole collected by the U.S. Geological Survey in 2000 (LA2000) and amosite material collected by RTI International (RTI amosite). The particle characterization data were generated to support a portion of the Libby Action Plan. Prior to analysis, the raw LA2000 and RTI amosite materials were subjected to a preparation step. Each sample was water-elutriated by U.S. Environmental Protection Agency (USEPA) Office of Research and Development, Research Triangle Park using the methods generally described in another published report and then delivered to the U.S. Geological Survey, Denver Microbeam Laboratory for analysis. Data presented here represent analyses performed by the U.S. Geological Survey, Denver Microbeam Laboratory and USEPA National Enforcement Investigations Center. This report consists of two Excel spreadsheet files developed by USEPA, Region 8 Superfund Technical Assistance Unit and describe the particle size characterization of the LA2000 and RTI amosite, respectively. Multiple tabs and data entry cells exist in each spreadsheet and are defined herein.

Open-File Report↗

Understanding the Avian-Impact Offset Method—A tutorial

Biodiversity offsetting, or compensatory mitigation, is increasingly being used in temperate grassland and wetland ecosystems to compensate for unavoidable environmental damage from anthropogenic disturbances such as energy development and road construction. Energy-extraction and -generation facilities continue to proliferate across the natural landscapes of the United States, yet mitigation tools to ameliorate the negative behavioral effects on wildlife from these types of facilities are rarely implemented. Scientists from the U.S. Geological Survey conducted a 10-year before-after-control-impact (commonly referred to as BACI) study that evaluated the displacement effects of wind facilities on breeding grassland birds. The study determined behavioral avoidance for 7 of 9 species. This research is notable because of its design, geographical scope, and duration, which allowed for the determination of immediate, short-term effects; delayed or sustained effects; and discrete distances at which effects occurred. In addition, the U.S. Fish and Wildlife Service and Ducks Unlimited conducted a 3-year concurrent-year paired-reference study to determine behavioral avoidance for five species of dabbling ducks. By quantifying displacement rate from these two studies, U.S. Geological Survey and U.S. Fish and Wildlife Service scientists developed the Avian-Impact Offset Method (AIOM) to quantify and compensate for loss in value of breeding habitat. The AIOM converts the biological value (that is, number of bird pairs) lost by way of avoidance and estimates the site-specific number of hectares of grasslands and number of wetlands needed to compensate for displaced pairs of grassland birds and waterfowl. By converting biological value to traditional units of measure in which land is described and purchased or sold, the AIOM lends itself readily to the delivery of offsetting measures such as easement protections and restoration projects. The AIOM tool is applicable to wind, solar, oil, gas, and transportation infrastructure. This tutorial was designed to increase awareness of the AIOM and to promote its proper application. The tutorial is divided into four sections, each of which explains a discrete topic concerning aspects of behavioral displacement. The first section provides geographical and biological context, and the second section describes the field and statistical methods and results. The third section provides step-by-step instructions for applying the AIOM to several scenarios involving grassland birds or waterfowl at wind or oil facilities. The fourth section describes decision-support tools created to implement the AIOM. The appendices provide the actual field protocols constituting the methods for the research, provide detailed results by species and wind facility for that research, and provide detailed instructions for downloading and applying the decision-support tools.

Open-File Report↗

Preliminary lithologic, geotechnical, and geophysical data from drill hole CW-81-2, Chuitna West coal field, Cook Inlet region, Alaska

The drilling and logging activity described in this report was undertaken in July 1981, as part of the Energy Lands program of the U.S. Geological Survey. The general objectives of the project of which this work is a part are to provide an understanding of the nature, location, and extent of the engineering geology and environmental geology concerns in areas of potential coal development in the Cook Inlet region, Alaska. The lithologic, geotechnical, and geophysical data presented in this report include some of the data needed to evaluate geologic hazards, and to predict the response of geologic materials to large-scale coal mining and related development in the Chuitna West coal field of the Beluga coal resource area. Specifically, the information may be used in evaluation of natural- and cut-slope stability, spoil-pile stability, ground response to seismic activity, blasting effects, excavatability, ground-water conditions, and erosion potential. The drill site (fig. 1, point C), located on the edge of a small, gently sloping basin draining northwestward into the Chuitna River, is approximately 90 km, (55 mi) west of Anchorage, Alaska, and 29 km (18 mi) northwest of Tyonek, a native village on the northwest side of Cook Inlet.

Alaska↗

Development of a geodatabase and conceptual model of the hydrogeologic units beneath air force plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas

Air Force Plant 4 and adjacent Naval Air Station-Joint Reserve Base Carswell Field at Fort Worth, Texas, constitute a government-owned, contractor-operated facility that has been in operation since 1942. Contaminants from AFP4, primarily volatile organic compounds and metals, have entered the ground-water-flow system through leakage from waste-disposal sites and from manufacturing processes. The U.S. Geological Survey developed a comprehensive geodatabase of temporal and spatial environmental information associated with the hydrogeologic units (alluvial aquifer, Goodland-Walnut confining unit, and Paluxy aquifer) beneath the facility and a three-dimensional conceptual model of the hydrogeologic units integrally linked to the geodatabase. The geodatabase design uses a thematic layer approach to create layers of feature data using a geographic information system. The various features are separated into relational tables in the geodatabase on the basis of how they interact and correspond to one another. Using the geodatabase, geographic data at the site are manipulated to produce maps, allow interactive queries, and perform spatial analyses. The conceptual model for the study area comprises computer-generated, three-dimensional block diagrams of the hydrogeologic units. The conceptual model provides a platform for visualization of hydrogeologic-unit sections and surfaces and for subsurface environmental analyses. The conceptual model is based on three structural surfaces and two thickness configurations of the study area. The three structural surfaces depict the altitudes of the tops of the three hydrogeologic units. The two thickness configurations are those of the alluvial aquifer and the Goodland-Walnut confining unit. The surface of the alluvial aquifer was created using a U.S. Geological Survey 10-meter digital elevation model. The 2,130 point altitudes of the top of the Goodland-Walnut unit were compiled from lithologic logs from existing wells, available soil-boring logs, and previous studies. Data from 120 wells, primarily from existing reports, were used to create a map of the approximate altitude of the Paluxy aquifer.

Texas↗

Fish Communities and Habitat of Geomorphically Stable Reference Reaches in Streams of the Catskill Mountain Region, New York

In 2002, the U.S. Geological Survey, in cooperation with the New York City Department of Environmental Protection, began a 5-year study to develop a database that documents the physical and biological characteristics of nine stable reference reaches from seven streams in the New York City West of Hudson Water Supply Watershed in the Catskill Mountain region of New York State. Primary objectives of this study were to (1) develop a reference-reach database of morphology, aquatic biology, and fluvial processes, and (2) summarize the relations between fish communities, aquatic habitat, and stable stream morphology in streams in the Catskill Mountain region. Secondary objectives included documenting year-to-year variability in fish populations and stream habitat in geomorphically stable streams and demonstrating how reliably Habitat Suitability Index models can be used to characterize habitat conditions and predict the presence and abundance of populations of trout species. Fish and habitat databases were developed, and several important relations were identified. Fish-community indices differed considerably among sites where trout were present and where they were either absent or present in very low numbers; these differences were reflected in higher Habitat Suitability Index scores at trout-dominated sites. Several fish- community and habitat variables were found to be strongly associated with indices of stability and, therefore, determined to be useful tools for evaluating stream condition. Lastly, preliminary results suggest Rosgen stream type data can help refine fish and habitat relations and assist in our ability to predict habitat potential and fish-community composition.

Scientific Investigations Report↗

Nutrient, organic carbon, and chloride concentrations and loads in selected Long Island Sound tributaries—Four decades of change following the passage of the Federal Clean Water Act

Trends in long-term water-quality and streamflow data from 14 water-quality monitoring sites in Connecticut were evaluated for water years 1974–2013 and 2001–13, coinciding with implementation of the Clean Water Act of 1972 and the Connecticut Nitrogen Credit Exchange program, as part of an assessment of nutrient and chloride concentrations and loads discharged to Long Island Sound. In this study, conducted by the U.S. Geological Survey in cooperation with the Connecticut Department of Energy and Environmental Protection, data were evaluated using a recently developed methodology of weighted regressions with time, streamflow, and season. Trends in streamflow were evaluated using a locally weighted scatterplot smoothing method. Annual mean streamflow increased at 12 of the 14 sites averaging 8 percent during the entire study period, primarily in the summer months, and increased by an average of 9 percent in water years 2001–13, primarily during summer and fall months. Downward trends in flow-normalized nutrient concentrations and loads were observed during both periods for most sites for total nitrogen, total Kjeldahl nitrogen, nitrite plus nitrate nitrogen, total phosphorus, and total organic carbon. Average flow-normalized loads of total nitrogen decreased by 23.9 percent for the entire period and 10.9 percent for the period of water years 2001‒13. Major factors contributing to decreases in flow-normalized loads and concentrations of these nutrients include improvements in wastewater treatment practices, declining atmospheric wet deposition of nitrogen, and changes in land management and land use. Loads of dissolved silica (DSi; flow-normalized and non-flow-normalized) increased slightly at most stations during the study period and were positively correlated to urbanized land in the basin and negatively correlated to area of open water. Concentrations and loads of chloride increased at 12 of the 14 sites during both periods. Increases likely are the result of an increase in the use of salt for deicing, as well as other factors related to urbanization and population growth, such as increases in wastewater discharge and discharge from septic systems.

Connecticut↗

Simulation of groundwater budgets and travel times for watersheds on the north shore of Long Island Sound, with implications for nitrogen-transport studies

Aquatic systems in and around the Long Island Sound (LIS) provide a variety of ecological and economic benefits, but in some areas of the LIS, aquatic ecosystems have become degraded by excess nitrogen. A substantial fraction of the nitrogen inputs to the LIS are transported through the groundwater-flow system. Because groundwater travel times in surficial aquifers can exceed 100 years, multiyear lags are introduced between inputs at the water table in recharge areas and discharge to inland or coastal receiving waters. The U.S. Geological Survey, in cooperation with the Connecticut Department of Energy and Environmental Protection and the U.S. Environmental Protection Agency’s Long Island Sound Study, developed a steady-state groundwater model of the watersheds draining from the northern shore of the LIS for the purpose of calculating groundwater budgets and travel times to coastal waters. The model was developed by using the MODFLOW–NWT software and existing spatial data on aquifers, river networks, land-surface altitudes, land cover, groundwater recharge, and water use. Coastal waters were delineated on the basis of the National Wetland Inventory; all non-coastal waters were collectively termed “inland waters.” A coarse-resolution model was calibrated by using the PEST++ software, long-term records of water levels in 65 wells, stream altitudes from 477 streams, base-flow records for 14 streamgages that are relatively unaffected by withdrawals, and error metrics based on incorrectly simulated flooding and incorrectly simulated dry streams. The calibrated values were used in a fine-resolution model in which the mean absolute residuals were 4.5 meters for groundwater levels, 1.3 meters for stream altitudes, and 7,200 cubic meters per day (2.9 cubic feet per second) for base flow. About 89 percent of the terrestrial cells were correctly simulated with the water table below land surface, and nearly 90 percent of the cells representing streams were correctly simulated as having the water table above the stream bottom. Together, these metrics suggest that this model is robust for simulating regional-scale groundwater patterns. Simulated groundwater budgets were compiled for the entire study area, for each HUC12 (Hydrologic Unit Code no. 12) watershed and its adjacent coastal waters, if applicable, within the study area, and for 14 coastal-embayment watersheds. Most groundwater (90.6 percent of inflows) discharged to inland waters, with smaller fractions to coastal waters (7.0 percent) and well withdrawals (2.4 percent). When computed for HUC12 watersheds with coastal discharge, the portions of groundwater discharging to coastal waters ranged from 0.02 to 66 percent of groundwater outflows, with a median of 13 percent. Within priority-embayment watersheds, the portions of groundwater discharging to coastal waters ranged from 2 to 56 percent, with a median of 15 percent. Groundwater travel times also were simulated for the entire study area, for each HUC12 watershed and its adjacent coastal waters, if applicable, within the study area and for 14 priority coastal embayments. Within the entire study area, the median groundwater travel time was 1.9 years, with an interquartile range of 0.1 to 5.9 years. Sensitivity analysis of groundwater travel times within a subbasin in the study area indicates that the travel times are a function of the grid resolution, with coarser grids resulting in shorter median travel times. Travel times for groundwater discharging to coastal waters were similar to travel times for groundwater discharging to inland waters, with a median of 1.9 years. Median travel times for the HUC12 watersheds ranged from 0.9 to 53.5 years, with a median of 1.8 years. Among HUC12 watersheds that include coastal areas, travel times for groundwater discharging to coastal waters ranged from less than 1 to 61.6 years, with a median of 2.8 years. The HUC12 watersheds with the longest simulated travel times were in the urban area near New York City where the model performance is less accurate. Median travel times for groundwater discharging to coastal waters within the priority-embayment watersheds ranged from less than 1 to 18.6 years, with a median of 2.3 years. A more focused analysis was conducted for the Niantic River watershed to demonstrate the applicability of the regional model to local-scale nitrogen-transport analyses by using nitrogen-input and -attenuation rates from literature sources. Nitrogen inputs were estimated by using land-cover-based loading factors, and attenuation was estimated by using attenuation factors based on geologic zones and soil properties. Based on this analysis, groundwater transports an estimated 22,000 kilograms of nitrogen per year (2.9 kilograms of nitrogen per hectare per year) to streams, rivers, and coastal waters within the Niantic River watershed. Approximately 36 percent of discharging nitrogen is from atmospheric-deposition sources, 38 percent is from fertilizers, and 26 percent is from septic systems. Most of the groundwater-transported nitrogen (88 percent) discharges first to streams and rivers, with only 12 percent discharging directly to coastal waters. Travel times for groundwater-transported nitrogen ranged from less than 1 day to more than 100 years, with a median of 1.6 years.

Connecticut, New York, Rhode Island↗

Approaches in highly parameterized inversion: TSPROC, a general time-series processor to assist in model calibration and result summarization

The TSPROC ( T ime S eries PROC essor) computer software uses a simple scripting language to process and analyze time series. It was developed primarily to assist in the calibration of environmental models. The software is designed to perform calculations on time-series data commonly associated with surface-water models, including calculation of flow volumes, transformation by means of basic arithmetic operations, and generation of seasonal and annual statistics and hydrologic indices. TSPROC can also be used to generate some of the key input files required to perform parameter optimization by means of the PEST ( P arameter EST imation) computer software. Through the use of TSPROC, the objective function for use in the model-calibration process can be focused on specific components of a hydrograph.

Techniques and Methods↗

Northeast

The distinct seasonality of the Northeast’s climate supports a diverse natural landscape adapted to the extremes of cold, snowy winters and warm to hot, humid summers. This natural landscape provides the economic and cultural foundation for many rural communities, which are largely supported by a diverse range of agricultural, tourism, and natural resource-dependent industries (see Ch. 10: Ag & Rural, Key Message 4) . The recent dominant trend in precipitation throughout the Northeast has been towards increases in rainfall intensity, with increases in intensity exceeding those in other regions of the contiguous United States. Further increases in rainfall intensity are expected, with increases in total precipitation expected during the winter and spring but with little change in the summer. Monthly precipitation in the Northeast is projected to be about 1 inch greater for December through April by end of century (2070–2100) under the higher scenario (RCP8.5). Ocean and coastal ecosystems are being affected by large changes in a variety of climate-related environmental conditions. These ecosystems support fishing and aquaculture, tourism and recreation, and coastal communities. Observed and projected increases in temperature, acidification, storm frequency and intensity, and sea levels are of particular concern for coastal and ocean ecosystems, as well as local communities and their interconnected social and economic systems. Increasing temperatures and changing seasonality on the Northeast Continental Shelf have affected marine organisms and the ecosystem in various ways. The warming trend experienced in the Northeast Continental Shelf has been associated with many fish and invertebrate species moving northward and to greater depths. Because of the diversity of the Northeast’s coastal landscape, the impacts from storms and sea level rise will vary at different locations along the coast. Northeastern cities, with their abundance of concrete and asphalt and relative lack of vegetation, tend to have higher temperatures than surrounding regions due to the urban heat island effect. During extreme heat events, nighttime temperatures in the region’s big cities are generally several degrees higher than surrounding regions, leading to higher risk of heat-related death. Urban areas are at risk for large numbers of evacuated and displaced populations and damaged infrastructure due to both extreme precipitation events and recurrent flooding, potentially requiring significant emergency response efforts and consideration of a long-term commitment to rebuilding and adaptation, and/or support for relocation where needed. Much of the infrastructure in the Northeast, including drainage and sewer systems, flood and storm protection assets, transportation systems, and power supply, is nearing the end of its planned life expectancy. Climate-related disruptions will only exacerbate existing issues with aging infrastructure. Sea level rise has amplified storm impacts in the Northeast (Key Message 2), contributing to higher surges that extend farther inland, as demonstrated in New York City in the aftermath of Superstorm Sandy in 2012. Service and resource supply infrastructure in the Northeast is at increasing risk of disruption, resulting in lower quality of life, economic declines, and increased social inequality. Loss of public services affects the capacity of communities to function as administrative and economic centers and triggers disruptions of interconnected supply chains (Ch. 16: International, Key Message 1) . Increases in annual average temperatures across the Northeast range from less than 1°F (0.6°C) in West Virginia to about 3°F (1.7°C) or more in New England since 1901. Although the relative risk of death on very hot days is lower today than it was a few decades ago, heat-related illness and death remain significant public health problems in the Northeast. For example, a study in New York City estimated that in 2013 there were 133 excess deaths due to extreme heat. These projected increases in temperature are expected to lead to substantially more premature deaths, hospital admissions, and emergency department visits across the Northeast. For example, in the Northeast we can expect approximately 650 additional premature deaths per year from extreme heat by the year 2050 under either a lower (RCP4.5) or higher (RCP8.5) scenario and from 960 (under RCP4.5) to 2,300 (under RCP8.5) more premature deaths per year by 2090. Communities, towns, cities, counties, states, and tribes across the Northeast are engaged in efforts to build resilience to environmental challenges and adapt to a changing climate. Developing and implementing climate adaptation strategies in daily practice often occur in collaboration with state and federal agencies (e.g., New Jersey Climate Adaptation Alliance 2017, New York Climate Clearinghouse 2017, Rhode Island STORMTOOLS 2017, EPA 2017, CDC 2015 ). Advances in rural towns, cities, and suburban areas include low-cost adjustments of existing building codes and standards. In coastal areas, partnerships among local communities and federal and state agencies leverage federal adaptation tools and decision support frameworks (for example, NOAA’s Digital Coast, USGS’s Coastal Change Hazards Portal, and New Jersey’s Getting to Resilience). Increasingly, cities and towns across the Northeast are developing or implementing plans for adaptation and resilience in the face of changing climate (e.g., EPA 2017 ). The approaches are designed to maintain and enhance the everyday lives of residents and promote economic development. In some cities, adaptation planning has been used to respond to present and future challenges in the built environment. Regional efforts have recommended changes in design standards when building, replacing, or retrofitting infrastructure to account for a changing climate.

Report↗

Studying wind energy/bird interactions: a guidance document. Metrics and methods for determining or monitoring potential impacts on birds at existing and proposed wind energy sites

In the 1980s little was known about the potential environmental effects associated with large scale wind energy development. Although wind turbines have been used in farming and remote location applications throughout this country for centuries, impacts on birds resulting from these dispersed turbines had not been reported. Thus early wind energy developments were planned, permitted, constructed, and operated with little consideration for the potential effects on birds. In the ensuing years wind plant impacts on birds became a source of concern among a number of stakeholder groups. Based on the studies that have been done to date, significant levels of bird fatalities have been identified at only one major commercial wind energy development in the United States. Research on wind energy/bird interactions has spanned such a wide variety of protocols and vastly different levels of study effort that it is difficult to make comparisons among study findings. As a result there continues to be interest, confusion, and concern over wind energy development's potential impacts on birds. Some hypothesize that technology changes, such as less dense wind farms with larger, slower-moving turbines, will decrease the number of bird fatalities from wind turbines. Others hypothesize that, because the tip speed may be the same or faster, new turbines will not result in decreased bird fatalities but may actually increase bird impacts. Statistically significant data sets from scientifically rigorous studies will be required before either hypothesis can be tested.

Book↗

UTILIZATION OF GEOGRAPHIC INFORMATION SYSTEMS TECHNOLOGY IN THE ASSESSMENT OF REGIONAL GROUND-WATER QUALITY.

The U. S. Geological Survey (USGS) in cooperation with the U. S. Environmental Protection Agency Office of Pesticide Programs and several State agencies in Oregon has prepared a digital spatial database at 1:500,000 scale to be used as a basis for evaluating the potential for ground-water contamination by pesticides and other agricultural chemicals. Geographic information system (GIS) software was used to assemble, analyze, and manage spatial and tabular environmental data in support of this project. Physical processes were interpreted relative to published spatial data and an integrated database to support the appraisal of regional ground-water contamination was constructed. Ground-water sampling results were reviewed relative to the environmental factors present in several agricultural areas to develop an empirical knowledge base which could be used to assist in the selection of future sampling or study areas.

Conference Paper↗

Environmental DNA (eDNA) detection of nonnative bullseye snakehead in southern Florida

Bullseye Snakehead Channa marulius (Hamilton 1822) was first detected in the southern Florida town of Tamarac in 2000 and has been expanding its geographic range since. Environmental DNA (eDNA) analysis is a newly-developed technique used to noninvasively detect cryptic or low-density species or those that are logistically difficult-to-study. Genetic material shed into the environment through tissue and body fluids is concentrated from water samples and analyzed for the presence of target species eDNA. To help delineate Bullseye Snakehead’s geographic range, we developed and validated a species-specific eDNA assay for both quantitative and droplet digital PCR (ddPCR). We then used ddPCR to assess 16 locations in southeast Florida using 222 water samples collected from 2015 to 2018. Positive eDNA detections were obtained at all six locations that were within the known geographic range of Bullseye Snakehead. Furthermore, eDNA was detected in six of 10 locations that were previously thought to be outside the periphery of the range but hydrologically connected through the extensive canal system. Over the four years of sampling, estimated occurrence rates (ψ) remained stable and relatively high (ψ = 0.67 [95% credible interval (CI) 0.33–0.95]) near Tamarac, Florida, as compared to the most southern sampling locations (ψ = 0.0–0.37). Bulls- eye Snakehead eDNA estimated occurrence rates in the middle region increased between 2016 (0.28 [95% CI 0.03–0.94]) and 2017 (0.66 [95% CI 0.24–0.98]), potentially reflecting eDNA detections related to a growing or expanding population. Bullseye Snakehead eDNA was detected at low concentrations on the northern and eastern borders of Everglades National Park, which is an important conservation area and UNESCO World Heritage Site. Despite extensive sampling via electrofishing, no Bullseye Snakehead were visually detected in several locations that yielded positive eDNA samples. It is unclear whether eDNA was transported through flowing water or another vector. To date, collection records for this species are confined to urban canals; however, Bullseye Snakehead may use the interconnected system of canals to disperse to natural conservation areas such as Everglades National Park, Big Cypress National Preserve, and Water Conservation Areas, where it may impact native species via predation and competition.

Florida↗

ET–The key to balancing the water budget in the Southwest

Throughout the Southwest, state and federal water-resource managers are becoming increasingly concerned about the impacts of future groundwater development on the region’s limited water resources, environmentally sensitive ecosystems, and rural lifestyle. To address their concerns, scientists and engineers are deploying physically based mathematical models to assess and predict the potential effects of increased groundwater pumping. The accuracy of these predictions is directly related to how well water budgets are quantified and balanced at basin and regional scales.

Nevada↗

Inland habitat selection model for wintering whooping cranes

Inland habitat use by wintering Aransas-Wood Buffalo whooping cranes ( Grus americana ) is expected to increase given projected population growth and observations of some whooping cranes using inland winter habitat in addition to coastal marshes. We developed resource utilization functions using ‘random forests’ to model whooping crane use as a function of environmental covariates considered important for whooping crane use. Covariates associated with distance to cropland, distance to development, and wetness or standing water were the most influential in model prediction. The model estimated that the 50% predicted use contour encompassed 34,925 hectares (ha) and the 95% predicted use contour encompassed 328,928 ha within the study area. While presently limited by the small sample size of inland wintering areas observations ( n = 7 cranes with ≥50 locations), this model provides an initial tool for identifying potential impacts to whooping crane inland habitat use in proximity to anthropogenic development. The model can be expanded to incorporate future data to reduce uncertainty.

Texas↗

Juvenile moose stress and nutrition dynamics related to winter ticks, landscape characteristics, climate-mediated factors and survival

Moose populations in the northeastern United States have declined over the past 15 years, primarily due to the impacts of winter ticks. Research efforts have focused on the effects of winter tick infestation on moose survival and reproduction, but stress and nutritional responses to ticks and other stressors remain understudied. We examined the influence of several environmental factors on moose calf stress hormone metabolite concentrations and nutritional restriction in Vermont, USA. We collected 407 fecal and 461 snow urine samples from 84 radio-collared moose calves in the winters of 2017–2019 (January–April) to measure fecal glucocorticoid metabolites (fGCM) concentrations and urea nitrogen:creatinine (UN:C) ratios. We used generalized mixed-effects models to evaluate the influence of individual condition, winter ticks, habitat, climate and human development on stress and nutrition in calf moose. We then used these physiological data to build generalized linear models to predict calf winter survival. Calf fGCM concentrations increased with nutritional restriction and snow depth during adult winter tick engorgement. Calf UN:C ratios increased in calves with lighter weights and higher tick loads in early winter. Calf UN:C ratios also increased in individuals with home ranges composed of little deciduous forests during adult winter tick engorgement. Our predictive models estimated that winter survival was negatively related to UN:C ratios and positively related to fGCM concentrations, particularly in early winter. By late March, as winter ticks are having their greatest toll and endogenous resources become depleted, we estimated a curvilinear relationship between fGCM concentrations and survival. Our results provide novel evidence linking moose calf stress and nutrition, a problematic parasite and challenging environment and winter survival. Our findings provide a baseline to support the development of non-invasive physiological monitoring for assessing environmental impacts on moose populations.

Vermont↗

Synthesizing professional opinion and published science to build a conceptual model of Walleye recruitment

Understanding and predicting recruitment, longstanding goals in fisheries science and ecology, are complicated by variation in the importance of environmental drivers coupled with the dynamic nature of individual ecosystems. Developing an understanding of recruitment from well-monitored stocks offers an opportunity to overcome these complexities. We used a systematic literature review, a survey, and a workshop attended by professionals with expertise in recruitment of Walleye Sander vitreus to identify common environmental drivers of Walleye recruitment and additional sources of variation (i.e., context dependencies) among populations. The importance of individual environmental drivers, as well as the direction of their influence, differed as a function of geographic region, lake surface area, and Walleye life stage. The literature suggested abiotic conditions (e.g., temperature) during the first year of life were influential in determining recruitment. Professional opinion noted the importance of biotic factors, with prey availability and predation risk having the most consistent relationships with recruitment. We synthesized this information to propose a conceptual model that illustrates the suite of characteristics that shape Walleye recruitment over large spatial and temporal scales. Our findings emphasize the importance of first-year growth and system-specific contextual factors, which can alter the relative importance of the environmental drivers of recruitment.

Fisheries Magazine↗