Catastrophic Loss of Acropora palmata in the Florida Keys: Failure of the ‘Sorcerer’s Apprentice Effect’ to Aid Recovery Following the 2005 Atlantic Hurricane Season

Climate change scenarios predict stronger and more frequent hurricanes. We studied survival patterns of Acropora palmata during the hyper-active 2005 Atlantic Hurricane Season [AHS] to assess future effects of routinely elevated storm seasons. Before the start of the 2005 AHS, 105 colonies on three survey reefs in the EPA/NOAA Coral Reef Monitoring Project were marked and tracked through 2007. Only 13 of the original 105 marked colonies survived the 2005 AHS (12%). When grouped into classes based on a combination of size, morphology, and position, results show a highly significant interaction between these classes and survivorship (Chi Sq. = 23.61; d.f. = 1; ρ < 0.0001). None of the large, 3-D exposed corals, and few of the medium, 3-D exposed corals survived. By contrast, highest survivorship occurred among small, 2-D protected corals. Medium-sized, 2-D protected corals had intermediate survival rates. None of the corals that were loose on the bottom survived. By asexual reproduction mechanisms such as breakage and fission, the socalled ‘Sorcerer’s Apprentice Effects,’ these 13 original colonies were represented on the post-hurricane reef by 33 distinct propagules (9 pieces by breakage and 24 by fission). None of the colonies formed by breakage and only 3 of the colonies formed by fission remained by 2007. No putative sexual recruitment was observed in the two years following the 2005 AHS. As a matter of public policy, we should undertake colony cementation and snail removal as perhaps the only way to promote Acropora palmata regrowth and recolonization following catastrophic disturbances.