Long-term changes on coral reefs in booming populations of a competitive colonial ascidian

A long-term study of the common coral reef spatial competitor Trididemnum solidum (van Name), a benthic colonial ascidian, showed a 900 % increase in densities along the 84 km of hinging reef in Curacao over 15 yr. The pattern of distribution along the coast did not change significantly and showed long-term effects of philopatry. This pattern relates to limited dispersal potential and the impact of the clonal ecological strategy of this modular organism. All hard reef substrata were overgrown but between 1978 and 1993 there was a significant increase in the number of ascidian colonies overgrowing dominant scleractinian corals such as Montastrea annularis.