PS 11-35 - Identifying disease-resistant genotypes in the threatened staghorn coral, Acropora cervicornis

Tuesday, August 9, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Morgan V. Hightshoe, Steven Miller and Nicole D. Fogarty, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Dania Beach, FL
Background/Question/Methods

The staghorn coral, Acropora cervicornis, is a major reef-building scleractinian coral found throughout Florida and the Caribbean. Over the past four decades Caribbean Acropora species have experienced population declines between 80-98%. These declines are attributed primarily to temperature induced bleaching (where the coral loses their symbiotic algae commonly called zooxanthellae) and white-band disease (WBD). These two stressors are not mutually exclusive; the highest coral disease prevalence occurs after periods of thermal stress. While previous research indicates that disease-resistant genotypes exist among select A. cervicornis populations in Panama, it is unknown if such characteristics are found in Florida Keys populations. We tested the potential for WBD resistance among 48 A. cervicornis genotypes maintained in a Florida Keys nursery by grafting active disease fragments to apparently healthy fragments. After an application period of five days, tissue degradation was documented visually by the presence or absence of WBD, denoted by a characteristic margin where the zooxanthellate tissue is denuded from the skeleton.

Results/Conclusions

Preliminary data indicate that two genotypes show resistance to the direct application of active WBD. Further replication will help assess recovery potential and resilience of A. cervicornis in the natural population. Additionally, considerable efforts continue to be made throughout Florida and the Caribbean to grow A. cervicornis fragments in coral nurseries and outplant them to depauperate reefs. These results will help inform and potentially increase the efficacy of future management strategies of Acropora populations.