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Optimal hydrograph separation (OHS) uses a two-parameter recursive digital filter that applies specific conductance mass-balance constraints to estimate the base flow contribution to total streamflow at stream gages where discharge and specific conductance are measured. OHS was applied to U.S. Geological Survey (USGS) stream gages across the conterminous United States...

The relationship between dive behavior and oceanographic conditions is not well understood for marine predators, especially sea turtles. We tagged loggerhead turtles (Caretta caretta) with satellite-linked depth loggers in the Gulf of Mexico, where there is a minimal amount of dive data for this species. We tested for associations between...

Whitebark pine, a foundation species at tree line in the Western U.S. and Canada, has declined due to native mountain pine beetle epidemics, wildfire, and white pine blister rust. These declines are concerning for the multitude of ecosystem and human benefits provided by this species. Understanding climatic correlates associated with...

Accurate forecasts of the streamflow expected during late spring and summer in the Upper Klamath River Basin in southern-central Oregon and northern California are used by water management agencies to balance water allocations for agriculture, aquatic habitat, and hydropower-production needs. Streamflow forecasts are also used by irrigation farmers for...

Planning for sustainable landscapes is hampered by uncertainty in how species will respond to conservation actions amidst impacts from landscape and climate change. Planning decisions, including tradeoffs among competing species objectives, are complex. We developed a decision-support framework that integrates dynamic-landscape metapopulation models (DLMPs) and structured decision making (SDM) to...

Development in the southeastern U.S. coastal plain generates the need for a better understanding of how demographics (survival and abundance) of estuarine nekton respond to urbanization. Apparent survival and density of the dominant Atlantic coast salt marsh fish, Fundulus heteroclitus, were estimated in four North Carolina tidal creeks using...

Background: 3,3’-Dichlorobiphenyl (PCB-11) is a non-legacy PCB congener widely detected in environmental samples and has been detected in human serum, but its toxicity potential is poorly understood. Objectives: We measured PCB-11 in wild caught fish and assessed its embryotoxicity and interactions with the aryl hydrocarbon receptor (Ahr) pathway in developing zebrafish...

Irrigated agriculture and inland fisheries both make important contributions to food security, nutrition, livelihoods, and well-being. Typically, in modern irrigation systems, these components operate independently. Some practices, commonly associated with water use and intensification of crop production, can be in direct conflict with and have adverse impacts on fisheries. Food...

Forest ecosystems in eastern North America were in flux over the last several thousand years, well before Euro-American land clearance and the 20th-century onset of anthropogenic climate change. However, the magnitude and uncertainty of prehistoric vegetation change have been difficult to quantify because of the multiple ecological, dispersal, and sedimentary processes that govern the relationship...

Influenza A viruses are one of the most significant viral groups globally with substantial impacts on human, domestic animal and wildlife health. Wild birds are the natural reservoirs for these viruses, and active surveillance within wild bird populations provides critical information about viral evolution forming the basis of risk assessments...

One of the leading causes of global amphibian decline is emerging infectious disease. We summarize the disease ecology of four major emerging amphibian infectious agents: chytrids, ranaviruses, trematodes, and Perkinsea. We focus on recently developed quantitative advances that build on well-established ecological theories and aid in studying epizootic and enzootic...

This report documents a Soil-Water-Balance (SWB) model that was developed for an area covering the Blue Ridge, Piedmont, and Mesozoic basin fractured-rock aquifers in Fauquier County, Virginia, for the calendar years 1996–2015. The SWB model includes an area of 1,498 square miles, divided into 1,076-square-foot (100-square-meter) grid cells on which...

Protected lands like national parks are important refuges for threatened and endangered species as environmental pressures on wildlife and their habitats increase. The Northern Spotted Owl (Strix occidentalis caurina), a species designated as threatened under the Endangered Species Act, occurs on public lands throughout the western United States including Mount...

The Lone Tree deposit is located in the northern Battle Mountain mining district, Nevada. Prior to mine closure in 2006, Santa Fe Pacific Gold and Newmont produced 4.2 Moz of gold at an average grade of 2.06 g/t at Lone Tree, primarily from the N-S– to NNW-SSE–striking Wayne zone. The...

Model estimated monthly water balance (WB) components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff [R]) for 848 United States (U.S.) Geological Survey 8-digit hydrologic units located in the Mississippi River Basin (MRB) are used to examine the temporal and spatial variability of the MRB WB for water years 1901 through...

Reliable tools are needed by farmers and managers to estimate and mitigate impacts of altered hydrology and degraded water quality downstream of agricultural areas. The Water, Energy, and Biogeochemical Model (WEBMOD) (Webb and Parkhurst 2017) was used to simulate daily variations of hydrology and water quality for 5 square kilometers...

Knowledge of the dietary components of fish species is important for understanding their growth, survival, and recruitment. Deficiency in thiamine (vitamin B1) leading to reproductive failure and physiological illness among freshwater fishes has been attributed to thiaminase activity in fish in the Great Lakes and the New York Finger Lakes,...

Lakes support globally important food webs through algal productivity and contribute significantly to the global carbon cycle. However, predictions of how broad-scale lake carbon flux and productivity may respond to future climate are extremely limited. Here, we used an integrated modeling framework to project changes in lake-specific...

Understanding the drivers and timescales over which groundwater quality changes informs groundwater management, use, and protection. To better understand timescales of water-quality change over short (daily to monthly) and long (seasonal to decadal) timescales, the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Enhanced Trends Network (ETN) program instrumented and sampled...

Semantic technology based on the Resource Description Framework (RDF) modeling environment has introduced new data management capabilities that can lead to innovative cartographic techniques. This report describes research toward more semantically expressive linked geospatial data mapping, topics of research, and an avenue for further  international collaboration....

In the USA, the Topeka shiner (Notropis topeka) is a federally listed endangered species that has been in decline for decades. A key reason for the decline is the alteration of naturally flowing streams and associated oxbow habitats resulting from land-use changes. The focus of recent conservation efforts for...

The Santa Fe Group aquifer is an important source of water to communities within the Middle Rio Grande Basin, including the Albuquerque-Rio Rancho metropolitan area and Kirtland Air Force Base, New Mexico. In November 1999, Kirtland Air Force Base personnel observed fuel-stained soils at the Bulk Fuels Facility on the...

1) Background: Critical Zone Processes in the Anthropocene The Earth’s Critical Zone encompasses a suite of interconnected processes in the near-surface lithosphere, pedosphere, biosphere, atmosphere, and hydrosphere (Brantley et al., 2007; Lin, 2010) (Fig. 1). Processes and interactions both within and between these various Critical Zone components supports life-sustaining ecosystem services...

The Land Change Monitoring, Assessment, and Projection (LCMAP) initiative uses temporally dense Landsat data and time series analyses to characterize landscape change in the United States from 1985 to present. LCMAP will be used to explain how past, present, and future landscape change affects society and natural systems. Here, we...

Iron and steel slags from legacy and modern operations in the Chicago-Gary area of Illinois and Indiana, USA, are predominantly composed of Ca (10 - 44 wt. % CaO), Fe, (0.3 - 28 wt. % FeO), and Si (10 - 44 wt. % SiO2), with generally lesser amounts of Al...