Abstract


REEF CONSTRUCTION AND DECONSTRUCTION IN THE FLORIDA KEYS, U.S.A.

Mirroring global trends, coral reefs in the Florida Keys have lost significant coral cover since the 1970s. The main reef-building process, coral calcification, has undoubtedly slowed on a region-wide scale resulting from declines in cover of massive head corals and the large, branching Acropora spp. In examining the coral record, however, it remains to be determined whether coral growth rates (linear extension or calcification) have systematically changed over the past two centuries. We present spatial and temporal patterns in existing and new data on coral growth rates for four reef-building species in the Florida Keys. We also examine the deconstruction side of the equation by quantifying decadal-scale rates of reef erosion by completing a study started in 1998 wherein dead coral heads were fitted with erosion-resistant cement and stainless-steel markers. In 2015, we revisited the site and found an average of 94 mm (std dev: 56) of reef elevation loss at 28 stations during the 17.3 year period. With the estimated rate of reef erosion at 5.4 mm per year, reefs that are presently devoid of coral cover in the Florida Keys are rapidly being eaten away by grazers and bioeroders. Conservation efforts intended to increase the abundance of parrotfish may, therefore, have adverse results in the Florida Keys and in other areas where herbivores are not targeted fisheries. Managing reefs with respect to physical resilience, in addition to ecological resilience, could optimize the expenditure of resources in conserving reefs and the services they provide.

Authors

Kuffner, I. B., U.S. Geological Survey, USA, ikuffner@usgs.gov

Toth, L. T., U.S. Geological Survey, USA, ltoth@usgs.gov

Hudson, J. H., Reef Tech, Inc., USA, hhudson3@bellsouth.net

Goodwin, W. B., NOAA Florida Keys National Marine Sanctuary, USA, bill.goodwin@noaa.gov

Jackson, K. L., University of Miami RSMAS, USA, kjackson@rsmas.miami.edu

Rosenberg, A. D., International SeaKeepers Society, USA, angela@seakeepers.org

Stathakopoulos, A., U.S. Geological Survey, USA, astathakopoulos@usgs.gov

Details

Oral presentation

Session #:18
Date: 06/22/2016
Time: 10:45
Location: 301 B

Presentation is given by student: No