Sea urchin herbivory has been demostrated to be a controlling factor in limiting the distribution of kelp forest habitats. But as yet, its role in limiting the distribution of seagrass habitats in inadequately investigated. In addition, bioturbation by infaunal invertebrates, i.e., ghost shrimp and sand dollars has also been suggested as limiting the local distribution of seagrass habitats, but the relative importance of bioturbation in controlling the size of seagrass meadows is also poorly understood. Field experiments will be conducted to identify the roles of sea urchin herbivory, bioturbation of seagrasses by sand dollars, and the potential interaction between sand dollar bioturbation and sea urchin herbivory in limiting the distribution of seagrass habitats. The results of this study should add to the existing body of knowledge and untested theories concerning the factors structuring nearshore ecosystems.
