HR: 0800h
AN: PP31A-0175    [Abstracts]
TI: Geochemical Signature of Land-based Activities in Caribbean Coral Surface Samples
AU: * Prouty, N G
EM: ngrumet@whoi.edu and ngprouty@usgs.gov
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, United States
AU: * Prouty, N G
EM: ngrumet@whoi.edu and ngprouty@usgs.gov
AF: United States Geological Survey, Pacific Science Center 400 Natural Bridges Drive, Santa Cruz, CA 95060, United States
AU: Hughen, K
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, United States
AU: Carilli, J
AF: Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093, United States
AB: Anthropogenic threats to the Mesoamerican Caribbean Reef Ecoregion, resulting from increased sedimentation, agrochemical run-off, coastal development, tourism and overfishing, are of great concern for future coral reef health and sustainability. Abundances of trace metal in corals can be used to monitor and identify the impact of land-based activities on the reef itself. In this study we demonstrate that surface coral samples from four sites in the Mesoamerican Caribbean Reef Ecoregion, Turneffe Atoll, Sapodilla Cayes and Honduras Bay Islands (Utila and Cayos Cochinos), yield statistically different chemical signatures due to their water quality and relative distance from pollution sources. Specifically, samples from the Sapodilla Cayes and the Bay Islands of Honduras yield elevated Ba/Ca and Mn/Ca levels, indicative of greater exposure to sediment-laden runoff form the south. In a similar manner, elevated coral Pb/Ca and Zn/Ca, and Sb/Ca and Cu/Ca values can be linked to mining activities and the use of antifouling paints, respectively. In addition, site heterogeneity was investigated by analyzing replicate cores at a single site from different colonies. We show that regional variability within the Sapodilla Cayes Marine Reserve can be explained by relative location and orientation within the reef and distance from the continental shelf. Our results indicate good reproducibility for the majority of trace metals investigated (not including Sr/Ca or Mg/Ca), suggesting that local environmental changes such as seawater chemistry, and not climate, is the dominant influence on the metal/Ca ratios.
DE: 4220 Coral reef systems (4916)
DE: 4808 Chemical tracers
DE: 4875 Trace elements (0489)
DE: 4916 Corals (4220)
DE: 4924 Geochemical tracers
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting