Regulation of population size of arborescent octocorals on shallow Caribbean reefs
On the reefs of St. John, US Virgin Islands, octocorals have thrived while stony corals have suffered a multi-decadal decline in abundance, creating dense animal forests of octocoral colonies. The similarity of these animal forests to their terrestrial counterparts raises questions of whether they are structured by similar density dependent ecologic processes. Species abundance surveys conducted from 2014-2018 at six reef sites in St. John provide limited support for density dependent recruitment and self-thinning among Eunicea spp., but not among other genera nor for octocorals as a group. Although octocoral forests on Caribbean reefs bear similarities to terrestrial forests, the present study suggests these effects may be the product of different mechanisms of population regulation.