Seven years of research on a reef in St. John, US Virgin Islands: Lack of recovery following Hurrican Hugo (1989)

Rogers, Caroline; Garrison, Virginia; Grober-Dunsmore, Rikki

After Hurricane Hugo, coral populations severely decreased. This is a report on the recovery of these corals and other things like algae and fish. During a seven-year period from 1989 to 1995, hard coral cover decreased and algal growth increased on a reef in Virgin Islands National Park on St. John, US Virgin Islands. As a direct result of Hurricane Hugo in September 1989, total live coral cover declined from about 20 percent and 13 percent, and cover by the most abundant coral, Montastraea annularis decreased from about 7 percent to 5 percent. When Hurricanes Luis and Marilyn struck St. John in September 1995, the amount of living coral cover on the reef was still at the level observed after Hugo. Cover by macroalgae, which was less than 5 percent before Hugo, increased to more than 21 percent within two months as the algae exploited new substrate opened up by the storm. Although continuing to fluctuate, macroalgal cover reached its highest level (31 percent) after Hurricanes Luis and Marilyn. Grazing by herbivorous fishes and sea urchins is not intense enough to control macroalgal growth, which hinders coral regeneration and recruitment. The combination of hurricane damage and fishing pressure on this reef may result in further declines in coral and increase in algal cover, and the reef may never return to its pre-Hugo condition. Abstract provided by author.