Distribution of corals after Acanthaster planci (L) infestation at Tanguisson Point, Guam

Randall, Richard

Distributional analysis of the reef corals was undertaken at Tanguisson Point in the early part of 1970, one year after the starfish infection, and includes relative abundance of coral species and percentage of substrate occupied by living corals by reef zones and the distribution of corallum size and growth forms for the entire reef. By using coral distribution studies conducted prior to the starfish infestation period on an adjacent reef at Tumon Bay, a baseline value was established for the above parameters. Using this baseline data it was found that the total number of species at Tanguission Point had decreased from 146 to 96, and the number of genera from 36 to 33. In major zones of starfish infestation the per cent of reef surface covered by living coral dropped from 49 to 21 in the reef front zone, from 59 to less than 1 in the submarine terrace zone, and from 50 to less than 1 in the seaward slope zone. There was a relative decrease in all corallum size ranges except the 0-5 cm range and a relative decrease in all the coral growth forms differentiated, except the encrusting types. There is some coral recovery taking place as evidenced by the presence of small, newly established corals from planula settlement and the presence of small surviving patched of previous living corals.

Distribution of corals after Acanthaster planci (L) infestation at Tanguisson Point, Guam

Series