Long-Term Stony Coral Transplantation Success Offshore Southeast, Florida, USA

Transplanted coral (Order: Scleractinia) colony condition was surveyed at five injury event sites, two coral nurseries, and one impact minimization location off the coast of Broward County, Florida, USA in 2012. Because stony corals are long-lived and slow growing, generally growing less than one centimeter in diameter per year, determining transplantation success requires long-term (greater than two years) monitoring. Long-term monitoring efforts, however, are rarely completed. This study is unique in that it examined stony coral transplantation success of several projects over a time period of 6-17 years. Control colonies were also surveyed in order to compare naturally growing coral colonies to the experimental (transplanted) colonies. Because the transplantation activities at the projects examined in this study occurred over a long time period (oldest population occurred 17 years prior to this study and the youngest occurred six years), colony percent partial mortality was used as a measure of success (colony condition). A successful effort should result in transplanted colonies experiencing partial morality similar to that of control colonies over extended periods of time. The control colonies used came from Broward County Annual Monitoring sites, and the M/V Firat and the C/V Hind ship grounding sites. The experimental colonies used came from five injury events (C/V Hind, Clipper Lasco, M/V Firat, and M/V Spar Orion ship grounding sites and Hillsboro Cable Drag location), two stony coral nurseries (DERM Modules and Warren Modules), and one impact minimization location (Broward County Mitigation Boulders). With all control colonies pooled and experimental colonies pooled, no significant differences in colony partial mortality were found between the experimental and control colonies. Once each experimental coral colony was reattached to the substrate, it generally appeared similar to the control colonies; the mean percent mortality for control colonies was 50% (2.95 ±SE) and the mean percent mortality for experimental colonies was 56% (1.24 ±SE). However, differences were found between stony coral species within each treatment (control and experimental). Colony mortality for identified control corals was greatest for Porites astreoides, Siderastrea siderea, and Montastrea annularis complex. For experimental colonies, S. siderea and P. astreoides had the most mortality. The least mortality of the control corals were found in Montastrea cavernosa, Solenastrea bournoni, and Meandrina meandrites. Of the experimental colonies, S. bournoni, M. meandrites, and Montastrea annularis complex had the least mortality. Resource managers need to consider colony transplantation location, coral species, and percent initial colony mortality when allocating efforts for injury and impact minimization events. Also, project initial restoration and final reports documenting transplantation locations and colony species, size and/or mortality should to be more detailed; this would be beneficial for future monitoring efforts