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Publications

Publications from USGS science centers throughout the Southeast Region.

Filter Total Items: 10363

Pesticides in near-surface aquifers: An assessment using highly sensitive analytical methods and tritium Pesticides in near-surface aquifers: An assessment using highly sensitive analytical methods and tritium

In 1992, the U.S. Geological Survey (USGS) determined the distribution of pesticides in near-surface aquifers of the midwestern USA to be much more widespread than originally determined during a 1991 USGS study. The frequency of pesticide detection increased from 28.4% during the 1991 study to 59.0% during the 1992 study. This increase in pesticide detection was primarily the result of a...
Authors
D.W. Kolpin, D. A. Goolsby, E.M. Thurman

Difference in the crab fauna of mangrove areas at a southwest Florida and a northeast Australia location: Implications for leaf litter processing Difference in the crab fauna of mangrove areas at a southwest Florida and a northeast Australia location: Implications for leaf litter processing

Existing paradigms suggest that mangrove leaf litter is processed primarily via the detrital pathway in forests in the Caribbean biogeographic realm whereas herbivorous crabs are relatively more important litter processors in the Indo-West Pacific. To test this hypothesis, we used pitfall traps to collect intertidal crabs to characterize the crab fauna in a mangrove estuary in southwest...
Authors
C.C. McIvor, T. J. Smith

Gonadal steroidogenesis in-vitro from juvenile alligators obtained from contaminated or control lakes Gonadal steroidogenesis in-vitro from juvenile alligators obtained from contaminated or control lakes

The ubiquitous distribution of many contaminants and the nonlethal, multigenerational effects of such contaminants on reproductive, endocrine, and immune systems have led to concerns that wildlife worldwide are affected. Although the causal agents and effects are known for some species, the underlying physiological mechanisms associated with contaminant-induced reproductive modifications...
Authors
Louis J. Guillette, Timothy S. Gross, D. A. Gross, A. A. Rooney, H. Franklin Percival

Estimating shallow subsidence in microtidal salt marshes of the southeastern United States: Kaye and Barghoorn revisited Estimating shallow subsidence in microtidal salt marshes of the southeastern United States: Kaye and Barghoorn revisited

Simultaneous measurements of vertical accretion and change in surface elevation relative to a shallow (3-5 m) subsurface datum were made in selected coastal salt marshes of Louisiana, Florida, and North Carolina to quantitatively test Kaye and Barghoorn's contention that vertical accretion is not a good surrogate for surface elevation change because of autocompaction of the substrate...
Authors
Donald R. Cahoon, D.J. Reed, J.W. Day

Florida manatees Florida manatees

The endangered Florida manatee (Trichechus manatus latirostris) is a survivor. It is one of only three living species of manatees which, along with their closest living relative, the dugong (Dugong dugon), make up the Order Sirenia. This taxonomic distinctiveness reflects their evolutionary and genetic uniqueness. Sirenians are the only herbivorous marine mammals; manatees feed on...
Authors
Lynn W. Lefebvre, Thomas J. O’Shea

Reproduction and distribution of bald eagles in Voyageurs National Park, Minnesota, 1973-1993 Reproduction and distribution of bald eagles in Voyageurs National Park, Minnesota, 1973-1993

The bald eagle (Haliaeetus leucocephalus) is classified as a threatened species in Minnesota. In 1973, the National Park Service began monitoring the distribution and reproduction of bald eagles in and immediately adjacent to Voyageurs National Park to obtain data that park management could use to protect bald eagles from the effects of use of the park by visitors and from the expansion...
Authors
Leland H. Grim, Larry W. Kallemeyn
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