Publications
Publications from USGS science centers throughout the Southeast Region.
Filter Total Items: 10352
Reduced channel conveyance on the Wichita River at Wichita Falls, Texas, 1900-2009 Reduced channel conveyance on the Wichita River at Wichita Falls, Texas, 1900-2009
Recent floods on the Wichita River at Wichita Falls, Texas, have reached higher stages compared to historical floods of similar magnitude discharges. The U.S. Geological Survey (USGS) has operated streamflow-gaging station 07312500 Wichita River at Wichita Falls, Tex., since 1938 and flood measurements near the location of the present gage were first made in 1900. Floods recorded in 2007...
Authors
Karl Winters, Stanley Baldys, Russell Schreiber
Nutrient fluxes at the landscape level and the R* rule Nutrient fluxes at the landscape level and the R* rule
Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on...
Authors
Shu Ju, Donald L. DeAngelis
Food-web structure of seep sediment macrobenthos from the Gulf of Mexico Food-web structure of seep sediment macrobenthos from the Gulf of Mexico
The slope environment of the Gulf of Mexico (GOM) supports dense communities of seep megafaunal invertebrates that rely on endosymbiotic bacteria for nutrition. Seep sediments also contain smaller macrofaunal invertebrates whose nutritional pathways are not well understood. Using stable-isotope analysis, we investigate the utilization of chemosynthetically fixed and methane-derived...
Authors
Amanda W.J. Demopoulos, Daniel Gualtieri, Kaitlin Kovacs
Suspended-sediment concentration regimes for two biological reference streams in Middle Tennessee Suspended-sediment concentration regimes for two biological reference streams in Middle Tennessee
Temporal patterns of suspended-sediment concentration (SSC) duration and frequency (SSC regimes) were characterized and compared with biological impairment thresholds for two headwater streams in the Western Highland Rim of Tennessee. The SSC regimes were plotted as curves showing concentrations and durations of the annual longest and tenth-longest SSC excursions above 18 concentrations...
Authors
Timothy H. Diehl, William J. Wolfe
Modeling seasonal dynamics of small fish cohorts in fluctuating freshwater marsh landscapes Modeling seasonal dynamics of small fish cohorts in fluctuating freshwater marsh landscapes
Small-bodied fishes constitute an important assemblage in many wetlands. In wetlands that dry periodically except for small permanent waterbodies, these fishes are quick to respond to change and can undergo large fluctuations in numbers and biomasses. An important aspect of landscapes that are mixtures of marsh and permanent waterbodies is that high rates of biomass production occur in...
Authors
Fred Jopp, Donald L. DeAngelis, Joel C. Trexler
Groundwater conditions and studies in the Brunswick–Glynn County area, Georgia, 2008 Groundwater conditions and studies in the Brunswick–Glynn County area, Georgia, 2008
The Upper Floridan aquifer is contaminated with saltwater in a 2-square-mile area of downtown Brunswick, Georgia. This contamination has limited development of the groundwater supply in the Glynn County area. Hydrologic, geologic, and water-quality data are needed to effectively manage water resources. Since 1959, the U.S. Geological Survey has conducted a cooperative water program with...
Authors
Gregory S. Cherry, Michael F. Peck, Jaime A. Painter, Welby L. Stayton
Analysis and simulation of water-level, specific conductance, and total phosphorus dynamics of the Loxahatchee National Wildlife Refuge, Florida, 1995-2006 Analysis and simulation of water-level, specific conductance, and total phosphorus dynamics of the Loxahatchee National Wildlife Refuge, Florida, 1995-2006
The Arthur R. Marshall Loxahatchee Wildlife Refuge (Refuge) was established in 1951 through a license agreement between the South Florida Water Management District and the U.S. Fish and Wildlife Service (USFWS) as part of the Migratory Bird Conservation Act. Under the license agreement, the State of Florida owns the land of the Refuge and the USFWS manages the land. Fifty-seven miles of...
Authors
Paul Conrads, Edwin A. Roehl
Stratospheric microbiology at 20 km over the Pacific Ocean Stratospheric microbiology at 20 km over the Pacific Ocean
An aerobiology sampling flight at 20 km was conducted on 28 April 2008 over the Pacific Ocean (36.5° N, 118–149° W), a period of time that coincided with the movement of Asian dust across the ocean. The aim of this study was to confirm the presence of viable bacteria and fungi within a transoceanic, atmospheric bridge and to improve the resolution of flight hardware processing techniques...
Authors
David J. Smith, Dale W. Griffin, Andrew C. Schuerger
Epizootic ulcerative syndrome caused by Aphanomyces invadans in captive bullseye snakehead Channa marulius collected from south Florida, USA Epizootic ulcerative syndrome caused by Aphanomyces invadans in captive bullseye snakehead Channa marulius collected from south Florida, USA
Epizootic ulcerative syndrome (EUS) caused by the oomycete Aphanomyces invadans is an invasive, opportunistic disease of both freshwater and estuarine fishes. Originally documented as the cause of mycotic granulomatosis of ornamental fishes in Japan and as the cause of EUS of fishes in southeast Asia and Australia, this pathogen is also present in estuaries and freshwater bodies of the...
Authors
Ryan K. Saylor, Debra L. Miller, Mark W. Vandersea, Mark S. Bevelhimer, Pamela J. Schofield, Wayne A. Bennett
Direct and indirect effects of climate change on amphibian populations Direct and indirect effects of climate change on amphibian populations
As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population...
Authors
Andrew R. Blaustein, Susan C. Walls, Betsy A. Bancroft, Joshua J. Lawler, Catherine L. Searle, Stephanie S. Gervasi
Satellite tracking reveals habitat use by juvenile green sea turtles Chelonia mydas in the Everglades, Florida, USA Satellite tracking reveals habitat use by juvenile green sea turtles Chelonia mydas in the Everglades, Florida, USA
We tracked the movements of 6 juvenile green sea turtles captured in coastal areas of southwest Florida within Everglades National Park (ENP) using satellite transmitters for periods of 27 to 62 d in 2007 and 2008 (mean ± SD: 47.7 ± 12.9 d). Turtles ranged in size from 33.4 to 67.5 cm straight carapace length (45.7 ± 12.9 cm) and 4.4 to 40.8 kg in mass (16.0 ± 13.8 kg). These data...
Authors
Kristen M. Hart, Ikuko Fujisaki
Pleistocene carbonate stratigraphy of South Florida: Evidence for high-frequency sea-level cyclicity Pleistocene carbonate stratigraphy of South Florida: Evidence for high-frequency sea-level cyclicity
Pleistocene carbonates of south Florida and islands of the Florida Keys are currently divided into five marine sequences designated, from oldest to youngest, the Q1–Q5 units. The units include a mosaic of freshwater and shallow marine deposits that accumulated on the Florida platform during high sea-level stands. The units are separated by regional-scale subaerial-exposure surfaces that...
Authors
Todd D. Hickey, Albert C. Hine, Eugene A. Shinn, Sarah E. Kruse, Richard Z. Poore