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USGS Diving Operations Assist Sediment-Toxicity Studies in Western Long Island Sound
U.S. Geological Survey (USGS) dive-team personnel Dann Blackwood and Rick Rendigs recently helped collect sediment push cores at three sites in western Long Island Sound in support of sediment-toxicity studies. The work was conducted on October 14, 2005, in collaboration with researchers Pengfei Zhang of the City College of New York (CCNY) and Michael Melcer of the U.S. Merchant Marine Academy (USMMA) at Kings Point, N.Y. The USMMA motor vessel Dottie J was used to transport the divers and scientific crew to three sites in the sound—at Little Neck Harbor, Manhasset Harbor, and Hempstead Harbor—that ranged in water depth from 3 to 12 m, respectively. The divers gently pushed two 4.5-in.-diameter core tubes into the silty sediment at each site. After carefully extracting the cores from the bottom sediment, the divers placed them in a sampling basket and hauled them back to the surface. Sediment quality and recovery were regarded as excellent because the sediment surfaces were virtually undisturbed and the average length of recovered cores was approximately 50 cm. The cores will be dated by 210Pb-isotopic analysis and will be further analyzed for the chlorinated pesticides chlordane and DDT. Additional spectral analyses will be used to examine the chiral signature of chlordane residues to determine whether or not microbial degradation has occurred. This study is part of a CCNY project sponsored by the U.S. Environmental Protection Agency (EPA) for determining the "Concentrations and Enantiomeric Fractions of Chlordane in Sediments from Long Island Sound." (For additional information, visit URL http://mail.sci.ccny.cuny.edu/~pzhang/research.html.) The results will be compared with those of a sediment-toxicity survey originally carried out by the National Oceanic and Atmospheric Administration (NOAA)'s National Status and Trends (NS&T) Program in Long Island Sound from 1986 to 1991. The NS&T survey was designed to determine the spatial distribution and severity of toxicity of heavy metals and chlorinated hydrocarbons at sites within 20 coastal bays in Long Island Sound.
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in this issue:
special feature: Offshore Impacts of Hurricane Katrina Sediment-Toxicity Studies in Western Long Island Sound Sea-Floor Geology Off Massachusetts Coast Alvin Dives to Deep-Water Coral Habitats
Briefing on Coastal Research in Hawai'i USGS Research on the Kona Coast, Hawai'i
Native-Plant Landscaping in Florida
Dec. 2005 / Jan. 2006 Publications List |
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U. S. Department of the Interior | U.S. Geological Survey
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