The York Research Database

This chapter describes a prototypic, spatially structured model for hard corals and their main competitor, macroalgae. Hard corals certainly form spatially structured populations, but whether they form true metapopulations is less clear. A classic metapopulation envisages a large array of habitat patches that are either occupied by a population or not. The chapter presents a modeling framework for Caribbean reefs that appears to have some explanatory power at local ecological scales. The connectivity scenarios are unrealistic but suggest that the importance of larval connectivity in coral population dynamics is highly sensitive to the degree of overfishing of herbivores in local populations. Overfished reefs decline even when larvae are not limiting, whereas unfished reefs exhibit a variety of dynamics and are influenced by larval supply. The implications of these results for the design of no-take marine reserves need further consideration. The model can be improved in several ways, including the use of realistic connectivity matrices between reefs, the addition of outbreaks of coral disease, and the expected impact and frequency of mass bleaching events.