HR: 0830h
AN: H51E-01    [Abstracts]
TI: Importance of Chemolithoautotrophic Production to Mobile Benthic Predators in the Gulf of Mexico
AU: Morgan, E
EM: macavoy@american.edu
AF: The American University, Biology Department , Washington DC, DC 20016 United States
AU: * MacAvoy, S
EM: macavoy@american.edu
AF: The American University, Biology Department , Washington DC, DC 20016 United States
AU: Carney, R
EM: macavoy@american.edu
AF: Lousiana State University, Coastal Studies Institute, Baton Rouge, LA 70803 United States
AB: The continental slope of the Gulf of Mexico is characterized by substantial hydrocarbon seepage which provides reduced energy sources, both CH4 and H2S, for chemolithoautotrophs existing as endosymbionts within mussels and tubeworms found in dense colonies that provide habitat for an array of endemic and colonial fauna. The extent of trophic export of chemosynthetic biomass to the seep communities and the surrounding benthic communities in the Gulf, however, remains an open question. To elucidate the nutritional associations between seep residents and the surrounding benthos the carbon, nitrogen and sulfur stable isotope values of the hagfish Eptatretus sp., the giant isopod Bathynomus giganteus and the predatory snail Phymorhyncus sp. were interpreted through a three source, dual isotope mixing model. The model was able to assess the contributions of different isotopic signals to a mixture and thus could distinguish between photosynthetic/phytodetritus based sources, methanotrophic sources and thiotrophic sources. Incorporation of chemosynthetic based food sources was minimal on the whole and species specific; however some of the organisms considered in this study did incorporate nutrition from chemolithoautotrophic sources.
DE: 1040 Isotopic composition/chemistry
DE: 4804 Benthic processes/benthos
DE: 4830 Higher marine organisms
DE: 4870 Stable isotopes
SC: Hydrology [H]
MN: 2005 Joint Assembly