Smith College
San Salvador Island is located about 600 km ESE of Miami, FL, on an isolated carbonate platform well east of the Great Bahama Bank. Contemporary anthropogenic impacts include sport diving, subsistence and sport fishing, and increased tourism and development in the 1990s, particularly along the island's west coast. During June 1998 we surveyed 11 sites, including Acropora palmata-dominated bank-barrier reefs off the northern and southern coasts of the island and several patch reefs on the leeward western shelf. Macroalgal abundance was relatively low at most sites, with turf algae dominating (~40% cover); a seasonal bloom of Microdictyon marinum was conspicuous (up to 70% cover) at one patch reef site. Overall, the reef is in very good condition, and we found very low incidence of coral disease (< 1% of over 1800 coral colonies censused).
Because our survey occurred prior to the 1998 coral bleaching event, we observed negligible levels of bleaching. Standing (long) dead A. palmata reached 75% at some sites (overall mean = 45%), but we documented recruitment and some recovery of this species at several sites. Overall mean old mortality of all coral colonies ranged from 15-35%. Recent coral mortality was < 1-2% at most sites, but was more than 2X greater at sites frequented by sport divers, suggesting increasing negative human impact. Commercially important fish species like snapper and grouper were scarce at all sites, and an overall small size of snapper (< 30 cm) reflects some fishing pressure. Herbivorous fishes (Acanthuridae, Scaridae and Pomacentridae) represented 20-45% of total fish stocks. The recent passage of Hurricane Floyd very close to San Salvador Island during September 1999 likely had a strong impact on this reef system; we plan a follow-up survey to assess the damage from this natural disturbance.
For more information contact Paulette Peckol at ppeckol@email.smith.edu or Alan Curran at acurran@science.smith.edu.
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