Abstract Summary
Grazing rates of Caribbean reef ecosystems have been in decline for the better part of a century. Top-down trophic cascades driven by a long history of overfishing, disease, and mortality of key herbivore and foundation species, and strong bottom-up eutrophication have been synergistic in shifting Caribbean reefs from a system typified by a taxonomic dominance of corals in the benthic community to one devoid of corals and often dominated by sponges, octocorals, and algae. These radical shifts in the character of the benthic community have been accompanied or even preceded at times by massive declines in fish communities. As such, restoration programs have sought to reverse these phase shifts through both algal removal/management and direct enhancement of hard corals. A great deal of emphasis has been placed on the recovery of the long spined sea urchin, Diadema antillarum, as a means of mediating the proliferation of benthic algae. The failure of D. antillarum to recover throughout the region as well as the rareity of large herbivorous fishes has left the grazing functional niche largely vacant on many Caribbean reefs. Here, we present evidence of an alternative grazer, the Caribbean King Crab, Maguimithrax spinosissimus, which may, through density-enhancement, offer restoration practitioners and resource managers a substantial tool for algal management efforts on Caribbean reefs. Additionally, we present evidence that M. spinosissimus grazing results in a series of cascading effects which may improve conditions for community-level coral reef recovery.
