| Abstract: | The living coral reef present at the East Flower Garden bank is important for its unique value as a recreational fishing and SCUBA diving area. Three sites were established on the reef to study the processes affecting the hermatypic coral population present there. Nine cruises were made to one or more of these sites between June 1977 and May 1978. Coral population estimates were made using data from nine plotless line transects established at random on the reef. Live coral cover ranges from 47.1 to 86.0%, averaging 62.5%. Montastrea annularis is the most abundant species, occupying approximately 38.0% of the available substratum. Forty-nine station exhibiting abnormal or apparently unhealthy corals were selected in the vicinity of three study sites. Repetitive photographic techniques were used to monitor conditions of (1) competitive interactions among corals, (2) coral tissue necrosis, (3) predation of corals, (4) adverse effects of storms on the reef, and (5) mechanical damage. Rates of linear retreat of coral tissue varied from 0.1-5.0 cm/mo. Lateral growth rates of coral tissue varied from 0.04-2.0 cm/mo. The hydrozoan coral, Millepora ap. is the fastest growing coral investigated. The destructive conditions listed above are significant factors contributing to the net loss of living coral tissue on the reef. However, tissue loss appears to be at least partially balanced by lateral growth and recruitment of new coral colonies. The comparative values of losses and gains of living coral tissue have not yet been determined. |
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