Abstract Summary
The mass mortality of Diadema antillarum throughout the Caribbean in 1983-4 resulted in decreased herbivory and an increase in abundance of macroalgae on coral reefs in the region. This project intends to increase population densities of Diadema antillarum on reefs in Puerto Rico by releasing lab cultured urchins to enhance herbivory and coral recovery (recruitment rates, survival, and growth). During the summer months (May to October), Diadema settlers are collected on settlement plates set along the shelf edge in La Parguera, Puerto Rico. Settlers (0.4 mm to 1.0 mm test diameter) are brought back to the lab and grown out in aquaria and raceways. Once the urchins reach a size sufficient to reduce mortality (2.0 cm to 4.0 cm test diameter), they are then transplanted to reefs in Puerto Rico. The restocking of the urchins will increase herbivory to reduce algal cover, especially Ramicrusta, and promote coral recruitment and recovery.
