Publications
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Microplastics in the Delaware River, northeastern United States
Microplastics are a contaminant of increasing concern in aquatic environments. Our understanding of microplastics in freshwater environments has increased dramatically over the past decade, but we still lack information on microplastic occurrence and biological uptake in National Park Service (NPS) waters. During 2015–19, the U.S. Geological Survey and the NPS conducted a three-phase study of micr
Authors
Austin K. Baldwin, Andrew R. Spanjer, Brett Hayhurst, Donald Hamilton
The Long-term effect of bleeding for Limulus amebocyte lysate on annual survival and recapture of tagged horseshoe crabs
In the U.S., 525,000 horseshoe crabs (Limulus polyphemus) per year have been captured during 2013–2017, brought to biomedical facilities, and bled to produce Limulus amebocyte lysate (LAL), then mostly released to the area of capture. The Atlantic States Marine Fisheries Commission estimates short-term bleeding-induced mortality to be 15% (4% to 30%), resulting in mortality of approximately 78,750
Authors
David R. Smith, Joshua Newhard, Conor P. McGowan, C. Alyssa Butler
Environmental data associated with sites infected with white-nose syndrome (WNS) before October 2011 in North America
White-nose syndrome (WNS) is an emerging infectious disease of hibernating bats caused by a fungus previously known as Geomyces destructans and reclassified as Pseudogymnoascus destructans. The disease was first documented in 2006 in New York, has since spread across much of eastern North America, and as of January 2012, had caused the death of at least 5.7 to 6.7 million bats. Previous studies ha
Authors
Christopher S. Swezey, Christopher P. Garrity
Factors affecting nitrate concentrations in stream base flow
Elevated nitrogen concentrations in streams and rivers in the Chesapeake Bay watershed have adversely affected the ecosystem health of the bay. Much of this nitrogen is derived as nitrate from groundwater that discharges to streams as base flow. In this study, boosted regression trees (BRTs) were used to relate nitrate concentrations in base flow (n = 156) to explanatory variables describing nitro
Authors
Susan Wherry, Anthony J. Tesoriero, Silvia Terziotti
Ecological risk assessment of environmental stress and bioactive chemicals to riverine fish populations: An individual-based model of smallmouth bass Micropterus dolomieu
Ecological risk assessments play an important role in environmental management and decision-making. Although empirical measurements of the effects of habitat changes and chemical exposure are often made at molecular and individual levels, environmental decision-making often requires the quantification of management-relevant, population-level outcomes. In this study, we generalized a modeling frame
Authors
Yan Li, Vicki S. Blazer, Luke R. Iwanowicz, Megan K. Schall, Kelly Smalling, Donald E. Tillitt, Tyler Wagner
Improving the ability to include freshwater wetland plants in process-based models
Considerable effort and resources have been placed into conservation programs designed to reduce or alleviate negative environmental effects of crop production and into evaluation of the benefits of these programs. Wetlands are an important source of ecosystem services, but modeling wetland plants is an emerging science. To date, wetland plant growth has not been explicitly accounted for in ecosys
Authors
Amber S. Williams, David M. Mushet, Megan Lang, Gregory W. McCarty, Jill A. Shaffer, Sharon N. Kahara, Mari-Vaughn V. Johnson, James R. Kiniry
Meeting the challenge: U.S. Geological Survey North Atlantic and Appalachian Region fiscal year 2020 in review
The utilization, preservation, and conservation of the Nation’s resources requires well-informed management decisions. The North Atlantic and Appalachian Region (NAAR) of the U.S. Geological Survey (USGS) supports science-based decision making for Federal, State, and local policymakers to meet the challenges of today and into the future. The science centers in the NAAR have well-deserved reputatio
Authors
By
Chesapeake Bay Activities, Florence Bascom Geoscience Center, Geology, Minerals, Energy, and Geophysics Science Center, Maryland-Delaware-D.C. Water Science Center, National Minerals Information Center, New England Water Science Center, New Jersey Water Science Center, New York Water Science Center, Ohio-Kentucky-Indiana Water Science Center, Pennsylvania Water Science Center, Virginia and West Virginia Water Science Center, Woods Hole Coastal and Marine Science Center, Office of Tribal Relations
Spatial and temporal patterns of low streamflow and precipitation changes in the Chesapeake Bay Watershed
Spatial and temporal patterns in low streamflows were investigated for 183 streamgages located in the Chesapeake Bay Watershed for the period 1939–2013. Metrics that represent different aspects of the frequency and magnitude of low streamflows were examined for trends: (1) the annual time series of seven‐day average minimum streamflow, (2) the scaled average deficit at or below the 2% mean daily s
Authors
Brandon Fleming, Stacey A. Archfield, Robert M. Hirsch, Julie E. Kiang, David M. Wolock
Groundwater discharges as a source of phytoestrogens and other agriculturally derived contaminants to streams
Groundwater discharge zones in streams are important habitats for aquatic organisms. The use of discharge zones for thermal refuge and spawning by fish and other biota renders them susceptible to potential focused discharge of groundwater contamination. Currently, there is a paucity of information about discharge zones as a potential exposure pathway of chemicals to stream ecosystems. Using therma
Authors
Tyler J. Thompson, Martin A. Briggs, Patrick J. Phillips, Vicki S. Blazer, Kelly L. Smalling, Dana W. Kolpin, Tyler Wagner
Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17α-ethinylestradiol)
Endocrine disrupting contaminants are of continuing concern for potentially contributing to reproductive dysfunction in largemouth and smallmouth bass in the Chesapeake Bay watershed (CBW) and elsewhere. Exposures to atrazine (ATR) have been hypothesized to have estrogenic effects on vertebrate endocrine systems. The incidence of intersex in male smallmouth bass from some regions of CBW has been c
Authors
Jessica Kristin Leet, Catherine A. Richter, Robert S. Cornman, Jason P. Berninger, Ramji K. Bhandari, Diane K. Nicks, James L. Zajicek, Vicki S. Blazer, Donald E. Tillitt
Mapping stream and floodplain geomorphic characteristics with the Floodplain and Channel Evaluation Tool (FACET) in the Mid-Atlantic Region, United States
Quantifying channel and floodplain geomorphic characteristics is essential for understanding and modeling sediment and nutrient dynamics in fluvial systems. The increased availability of high-resolution elevation data from light detection and ranging (lidar) has helped improve methods for extracting these metrics at a greater accuracy across regional scales. The Floodplain and Channel Evaluation T
Authors
Marina Metes, Kristina G. Hopkins, Labeeb Ahmed, Samuel Lamont, Peter R. Claggett, Gregory Noe
Hydro-climatic drought in the Delaware River Basin
The Delaware River Basin (DRB) supplies water to approximately 15 million people and is essential to agriculture and industry. In this study, a monthly water balance model is used to compute monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff [R]) for the DRB for the 1901 through 2015 period. Water‐year R is used to identify drought periods i
Authors
Gregory J. McCabe, David M. Wolock