MASSIVE MORTALITY OF ZOOXANTHELATE REEF O RGANISMS DURING THE 1995 BLEACHING IN CAYOS-COCHINOS, HONDURAS

Coral reefs in Cayos Cochinos were affected during a severe bleaching event in 1995 associated with a 9-week (July-October) increase in sea surface temperature (>3.5 degrees C). All coral reefs within the 460 K m(2) Biological Reserve were initially surveyed during September. In O ctober, three reef sites were selected to quantify the extent of the d amage; healthy, bleaching and dead coral colonies were recorded in six -200 m(2) transects per reefs at two different depths. The bleaching e vent affected 73%, 92%, 97% and 95% of scleractinian corals, hydrocora ls (Millepora spp.), zoathids (Palythoa spp.) and octocorals, respecti vely. At the time of the survey, the highest mortality was observed in Millepora with 74% of the colonies followed by Palythoa (12%), octoco rals (8%) and scleractinian corals (6%). Whereas the number of totally dead colonies for scleractinian corals was low, all surviving colonie s, mostly Montastraea spp. and Agaricia spp., showed extensive partial mortality within the colony, and fewer colonies partially recovered b y the end of October. A second survey made in August 1996 at two of th e previously surveyed sites showed a high number of dead coral colonie s (83%). The bleaching event of 1995 appears to have triggered an infe ction of Black Band Disease; 34% of the colonies (Montastraea annulari s y M. faveolata) were infected, further increasing partial mortality of the colonies. The long-term impact of this event on the artisinal f ishery remains to be evaluated and it is predicted changes in stocks a bundance of commercially important species due to the lost of reef hab itats associated with this natural event. Managers at the Biological R eserve should consider the creation of new restricted fishing zones wi thin the protected area, including new fishing restrictions to allow r eef recovery and stock enhancement of valuable species.