Acanthaster: effect on coral reef growth in panama. Analysis of data on coral abundance and growth, and the population size (26 individuals per hectare) and feeding rate of Acanthaster indicates that Pocillopora reefs on the Pacific coast of Panama are undergoing vigorous growth in the presence of this predator. Prediction of the effects of a population increase in Acanthaster to plague proportions (2.5 times that presently observed) suggests that reefs could still maintain a positive growth. However, Acanthaster at ten times the present population density would lead to rapid destruction of reefs. It is argued that coral destruction due to Acanthaster represents only one of several factors affecting coral reef progression.