Publications
Publications from USGS science centers throughout the Southeast Region.
Filter Total Items: 9967
Predicting inundation dynamics and hydroperiods of small, isolated wetlands using a machine learning approach
The duration of inundation or saturation (i.e., hydroperiod) controls many wetland functions. In particular, it is a key determinant of whether a wetland will provide suitable breeding habitat for amphibians and other taxa that often have specific hydrologic requirements. Yet, scientists and land managers often are challenged by a lack of sufficient monitoring data to enable the understanding of t
Authors
Jeffrey W. Riley, Charles C. Stillwell
Considering pollinators' ecosystem services in the remediation and restoration of contaminated lands: Overview of research and its gaps
The concept of ecosystem services provides a useful framework for understanding how people are affected by changes to the natural environment, such as when a contaminant is introduced (e.g., oil spills, hazardous substance releases) or, conversely, when contaminated lands are remediated and restored. Pollination is one example of an important ecosystem service; pollinators play a critical role in
Authors
James Meldrum, Diane L. Larson, Timothy B. Hoelzle, Jo Ellen Hinck
White perch health relative to urbanization and habitat degradation in Chesapeake Bay tributaries. II. Hepatic and splenic macrophage aggregates
Macrophage aggregate (MA) abundance in fish is a useful general biomarker of contaminant exposures and environmental stress. Hepatic and splenic MAs were evaluated in semi-anadromous white perch Morone americana (Gmelin, 1789) from the urbanized Severn River (S) and the more rural Choptank River (C), Chesapeake Bay. Fish were collected from different sites in the annual migratory circuit in each r
Authors
Vicki S. Blazer, Mark A Matsche, Erin L. Pulster
White perch health relative to urbanization and habitat degradation in Chesapeake Bay tributaries. I. Biliary neoplasms and hepatic lesions
White perch Morone americana (Gmelin, 1789) from the Chesapeake Bay (USA) watershed have a high incidence of liver disease, including neoplasms of bile duct origin. Fish collected seasonally from spring 2019 to winter 2020 from the urban Severn River and the more rural Choptank River were evaluated for hepatic lesions. Biliary hyperplasia (64.1%), neoplasms (cholangioma and cholangiocarcinoma, 27%
Authors
Vicki S. Blazer, Mark A Matsche, Erin L. Pulster
Evolution of a minimal cell
Possessing only essential genes, a minimal cell can reveal mechanisms and processes that are critical for the persistence and stability of life1,2. Here we report on how an engineered minimal cell3,4 contends with the forces of evolution compared with the Mycoplasma mycoides non-minimal cell from which it was synthetically derived. Mutation rates were the highest among all reported bacteria, but w
Authors
Roy Z. Moger-Reischer, John I. Glass, Kim S. Wise, Lijie Sun, Daniela M.C. Bittencourt, Brent K. Lehmkuhl, Donald Schoolmaster, Michael Lynch, Jay T. Lennon
Identifying invertebrate indicators for streamflow duration assessments in forested headwater streams
Streamflow-duration assessment methods (SDAMs) are rapid, indicator-based tools for classifying streamflow duration (e.g., intermittent vs perennial flow) at the reach scale. Indicators are easily assessed stream properties used as surrogates of flow duration, which is too resource intensive to measure directly for many reaches. Invertebrates are commonly used as SDAM indicators because many are n
Authors
Ken M. Fritz, Roxolana O. Kashuba, Gregory J. Pond, Jay R. Christensen, Laurie C. Alexander, Benjamin J. Washington, Brent R. Johnson, David Walters, William T. Thoeny, Paul C. Weaver
Presence of hummock and hollow microtopography reflects shifting balances of shallow subsidence and root zone expansion along forested wetland river gradients
Tidal freshwater forested wetlands (TFFWs) are in an active phase of transition to tidal marsh with sea level rise and salinity incursion along the Atlantic and Gulf Coasts of the United States (U.S.). A prominent feature of TFFWs is hummock/hollow microtopography where hollows represent the flat, base-elevation of the floodplain where inundation occurs relatively frequently, while hummocks provid
Authors
Ken Krauss, Gregory Noe, Jamie A. Duberstein, Nicole Cormier, Andrew From, Thomas Rossiter Doody, William H. Conner, Donald Cahoon, Darren Johnson
2023 Coastal master plan: ICM-wetlands – Submerged aquatic vegetation (SAV) updates
Submerged aquatic vegetation (SAV) provides critical structural habitat for valuable nekton and wildlife species across coastal ecosystems and can buffer the negative effects of land loss. Landscape change and restoration efforts across coastal Louisiana can impact the occurrence, coverage, and species assemblages of SAV, and changes to these foundational species can have cascading impacts across
Authors
Kristin DeMarco, Donald Schoolmaster, Brady Couvillion
2023 Coastal master plan: Landscape input data
Coastal Louisiana is a complex landscape. The composition of the landscape, as well as the processes which influence said landscape, vary in both space and time. The models used in the 2023 Coastal Master Plan must attempt to reflect that spatial and temporal variability. It is therefore of the utmost importance that the spatial data sets upon which the models are initialized are of the highest qu
Authors
Brady Couvillion
Vortex trapping of sand grains over ripples under oscillatory flow
Sand ripples significantly impact morphodynamics in the nearshore by generating coherent vortices, which can transport suspended sediment to greater heights in the water column than above flat beds. Coherent vortices can trap sediment grains if the settling velocity of the grain is smaller than the maximum vertical fluid velocity in the vortex (Nielsen 1992). Particle image and tracking velocimetr
Authors
Donya P. Frank-Gilchrist, Allison Penko, Margaret Louise Palmsten, Joseph Calantoni
Assessing impacts of human stressors on stream fish habitats across the Mississippi River basin
Effective conservation of stream fishes and their habitats is complicated by the fact that human stressors alter the way in which natural factors such as stream size, catchment geology, and regional climate influence stream ecosystems. Consequently, efforts to assess the condition of stream fishes and their habitats must not only attempt to characterize the effects of human stressors but must acco
Authors
Jared Ross, Dana M. Infante, Arthur R. Cooper, Joanna B. Whittier, Wesley Daniel
Modeling surface wave dynamics in upper Delaware Bay with living shorelines
Living shorelines gain increasing attention because they stabilize shorelines and reduce erosion. This study leverages physics-based models and bagged regression tree (BRT) machine learning algorithm to simulate wave dynamics at a living shoreline composed of constructed oyster reefs (CORs) in upper Delaware Bay. The physics-based models consist of coupled Delft3D-FLOW and SWAN in four-level neste
Authors
Ling Zhu, Q. Chen, Hongqing Wang, Nan Wang, Kelin Hu, William D. Capurso, L.M. Niemoczynski, Gregg Snedden