USGS Measures Coral Reef Recovery in Culebra, PR

Last week the U.S. Geological Survey (USGS) examined the coral reefs around Culebra.   The study revealed that the rapid recovery observed following the devastation of the reef by Hurricane Hugo on September 18, 1989 has now slowed.  Rafael W. Rodríguez, Caribbean District Chief, reported this finding based on observations made by USGS scientists who revisited permanent monitoring sites established on the reefs in 1991.   The team photographed coral reefs at three sites to gain an understanding of how the corals have recuperated since Hurricane Hugo.

Coral reefs are sources of carbonate sand production, buffers to storm-wave induced coastal erosion, sites of high biologic productivity (important to local fisheries), and tourist attractions.  In 1991, direct observation by divers showed hurricane damage to the coral reefs to be extensive on the east and southeast sides of Culebra.  The most obvious effect of the storm was the near total destruction of the elkhorn coral, a principal reef builder in the Caribbean.  Virtually all colonies larger than 1 meter were overturned and fragmented.  Finger and staghorn corals were also greatly affected.  Large quantities of these delicate branching corals had been reduced to gravel-size rubble forming steep slopes that buried other corals.

Despite extensive damage to the reefs, abundant evidence of post-hurricane recruitment and regrowth was noted during 1991 and 1994.  The preliminary results of last week's study indicate that the rapid initial recovery by the reefs has now slowed.  Similar studies by the USGS in Florida and the U.S. Virgin Islands, and by scientists elsewhere in the Caribbean have shown that corals throughout the region are being stressed.   Nevertheless, the reefs in Culebra are in very good condition as compared to reefs in other parts of Puerto Rico, Florida, and the U.S. Virgin Islands.

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