Reefs--Florida

Reefs off the coast of Florida face threats from stressors associated with climate change which leads to phase shifts. Under rapid climate change, a clear understanding of how reefs and their benthic organisms respond is still lacking and needs to be investigated. Using in situ imagery, a sponge cell model, and long-term benthic biota surveys, the effects of climate change on reef dynamics were explored in this dissertation project. Results from the in situ imagery found that differences in spectral signatures are found between functional groups (i.e., corals, sponges, and algae) and different species from substrate. Results based on a sponge cell model and transcriptomics data have found a resilience of these sponges to the predicted thermal extremes. Results from benthic biota surveys suggested that depth and light attenuation have the largest influence on the predicted distribution of corals, sponges, and algae at Pulley Ridge. Climate change has been impacting reef benthic biota starting at the organismal scale up to the reef scale. This research demonstrates the importance of monitoring reefs at a finer scale and determining the thresholds and limits of benthic biota to projected thermal extremes to better inform resource managers to preserve these irreplaceable ecosystems.

An underwater survey was performed between July 1987 and August 1990 focusing on the entire nearshore reef tract situated along the shoreline of Palm Beach County, Florida. Transects, aligned on Florida Department of Natural Resources survey monuments, commenced from the high water mark waterward to the 4 meter isobath. A total of 125 of the 228 transects were found to contain nearshore reefs. A matrix of reef characteristics was created based upon the value of six indices including reef width and profile, biodiversity, beach width, public access and an assessment of the historical permanence of the reef. This matrix, based on "z" scores, provided a means of comparing each nearshore reef transect station within the County. This evaluative scheme was used to develop recommendations for the protection and management of the nearshore reefs.