Distribution predictions and biological impacts of marine debris in Miami-Dade County, Florida

Marine debris is found in all oceans and is recognized as one of the most environmentally damaging marine pollutants. In South Florida, submerged marine debris negatively impacts marine life along the Florida Keys Reef Tract (FKRT), a resource of ecological and socioeconomic importance. In a 2012 study by Watson, analysis of the locations of \u3e1,000 submerged marine debris sightings over a 9-year period by the National Oceanic and Atmospheric Administration Southeast Fisheries Science Center’s Reef Visual Census (RVC) program identified a debris ‘hot-spot’ on the portion of FKRT adjacent to Biscayne. This study aimed to; 1.) Determine the viability of using the RVC marine debris database in planning removal events; 2.) Remove as much debris as possible from the proposed Biscayne ‘hot-spot’; and 3.) Determine the impact of debris to coral reef benthic invertebrates. From June to July, 2012, 9 ‘Debris’ sites, where debris was previously listed as present by RVC surveys, and 10 ‘Control’ sites, where debris was not listed as present on previous RVC surveys, within the Biscayne Bay ‘hot-spot’ were selected for sampling. A team of two SCUBA divers employing the roving diver technique conducted surveys. Debris was present at all sites, and no difference in debris density was found between ‘Debris’ and ‘Control’ sites. ‘Trap’ debris was the most commonly encountered debris type, accounting for 68% of all debris, in addition to being the most damaging to benthic invertebrates. Soft corals were the most commonly damaged organisms, accounting for 41% of all injuries. This study verifies the marine debris ‘hot-spot’ adjacent to Biscayne Bay, as debris was present at all sites. However, the lack of difference in debris densities between ‘Debris’ and ‘Control’ sites suggest that the RVC database may not be useful in site selection for removal events on a fine scale. Additionally, the presence of debris at ‘Control’ sites suggests that RVC data underestimated the true extent of debris within the study area. ‘Trap’ debris was the most prevalent and impactful debris type. Policies should be tailored towards including commercial fishermen in derelict trap removal events during commercial fishing season