Acropora palmata's Last Stand in the Florida Keys?
13th International Coral Reef Symposium, Honolulu, Hawaii, June 19-24, 2016
The decline of acroporid corals throughout the Caribbean over the last 30 years has been well-documented, with noted mortality of this primary reef-builder most evident along the Florida Reef Tract. While the framework of bank reefs created by Acropora palmata remains, the spatial extent of the population itself has dwindled so substantially that only few areas of multiple extant colonies remain across the reef tract as a whole. Data from recent monitoring at 10 sites in the Florida Keys reflect particularly alarming losses, including localized extirpation at a few sites within the Lower Keys. These losses are not equally distributed across sites, and while chronic drivers of decline (predation and disease) occurred at all sites, their relative impact is neither geographically nor temporally uniform. Recent severe bleaching events of 2014 and 2015 affected sites differently as well, notably causing near complete mortality at sites chronically impacted by corallivorous snails as well as sites previously showing high growth and low mortality (although low genotypic diversity). The prevalence of corallivorous snail predation increased on the remaining colonies and continued to cause high mortality on the remaining tissue. Ultimately, chronically stressed corals seemed to be more susceptible to bleaching events, but even sites documented as healthy can suffer mass mortality. With an extensive El Nino event expected to continue in 2016, Florida’s Acropora palmata population may become increasingly restricted to even fewer sites. Minimizing local stressors may provide some relief for A. palmata, but it will not remove the bleaching threat.
Semon-Lunz, K.; Wirt, K.; Neely, Karen L.; Williams, D.; and Whittle, A., "Acropora palmata's Last Stand in the Florida Keys?" (2016). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 525.