Use of Aquacultured Coral Fragments for Restoration Activities in the Florida Keys
Florida is the only state in the continental United States that has extensive shallow coral reef formations near its coasts, from the Florida Keys starting south of Miami reaching west to the Dry Tortugas. Caribbean coral reefs are under increasingly destructive pressures from various sources, including dredging, ship groundings, pollution, and illegal collecting. The state's Comprehensive Conservation Wildlife Strategy of 2005 cited coral reefs as a priority habitat, labeled "bad and in decline." Over 200 species of birds, mammals, fish and invertebrates, including numerous coral species, were designated "species of greatest conservation need."
Filling in data gaps on coral restoration techniques and health of coral fragments that are used will contribute significantly to the Florida Wildlife Strategy. Recent work by The Florida Aquarium, the Florida Keys National Marine Sanctuary (FKNMS), Mote Marine Laboratory and the University of Florida has shown that many species of Atlantic Scleractinia can be fragmented and grown successfully in aquaculture systems, and on underwater sites. With support from a Wildlife Legacy Initiative grant (SWG04-038), the partners began addressing two primary questions concerning the use of aquacultured fragments for restoration: 1) whether culture techniques affect survival and growth of reintroduced fragments and 2) could these fragments become a vector for disease when returned to a restoration site?
Much progress has been made. The team cut 210 fragments from 7 species (30 per species) of coral collected from the Truman Annex site in Key West Harbor, 6 listed as having greatest conservation need in the state's Wildlife Strategy. The aquacultured corals (Siderastrea radians, Solenastrea bournoni, Montastrea annularis, Montastrea cavernosa, Diploria clivosa, Dichocoenia stokesii, and Stephanocoenia michellini) were distributed to two culture locations and one open reef site. The land-based fragments were grown in culture for approximately 7 months prior to transplantation in the field. Transplantation of corals to Miss Beholden grounding site, Western Sambo Reef, occurred in December, 2006. Monitoring of the site will follow 3 month intervals for 2 more years. Addressing the second question, the team developed a standard best management practice to properly quarantine corals in culture and ensure that corals intended for reintroduction are healthy prior to restoration. These procedures and other diagnostic methods were used to develop criteria for issuance of a federal health certification before reintroduction of corals to restoration sites or where otherwise required.
As this study has advanced, many additional questions have arisen that could impact the successful use of aquacultured corals to rehabilitate reefs. The partnership expanded to include additional coral restoration stakeholders from around the state, including marine microbial biologists from the University of South Florida and geneticists from Florida Atlantic University. To help focus future studies, the working group, known as the Florida Cultured Coral Conservation Consortium (The 4 C's,) adapted a 10 point list from Blankenship and Leber1 (1995) on a reasonable approach to marine stock enhancement.
Additional funding has been obtained to: 1) continue monitoring the first study set of corals, 2) explore the relationship between mounting techniques and subsequent coral growth and health; 3) further evaluate microbial health of corals in culture and changes when reintroduced to the field; and 4) assess genetic variation among local and regional corals to begin to understand the potential geographic range of coral fragments used in restoration. The various studies are designed to maximize fragment use, and to coordinate collection and monitoring efforts to minimize time and cost by integrating many of the outstanding questions surrounding the successful use of cultured coral fragments for reef restoration. Montastrea annularis and M. cavernosa have been selected for the microbial and genetic studies due to the abundance of rescued parent colonies available and their ability to grow well in captive settings. In future studies the team plans to test additional coral species.
1. Blankenship HL, KM Leber. 1995. A Responsible Approach to Marine Stock Enhancement. American Fisheries Society Symposium 15:167-175.