Abstract
Florida is the only state in the continental United States with extensive shallow coral reef formations near its coasts, from the Florida Keys south of Miami to the Dry Tortugas. According to the National Oceanic and Atmospheric Administration's (NOAA) State of the Coast report (1998), these reefs are under significant stress and have suffered extensive habitat loss. Coral reefs in the Florida Keys are under increasingly destructive pressures from various sources, including dredging, ship groundings, pollution, and illegal collecting. In addition to the coral, reef destruction impacts a rich habitat that includes over 100 species of fish. The Florida Keys, where coral reefs are a major attraction, bring in an estimated $1.2 billion in tourism to the state of Florida annually.
Coral propagation for restoration has proven successful both in open-ocean efforts and in land-based facilities. Scleractinia and other coral taxa are now under wide-scale production by numerous cultivation techniques. Recent efforts involving the Florida Keys National Marine Sanctuary (FKNMS), The Florida Aquarium, the University of Florida, and others have shown that many species of Atlantic Scleractinia can be fragmented and grown successfully in tanks and on underwater lease sites.
The Florida Aquarium, the University of Florida, and biologist Ken Nedimyer received coral colonies from FKNMS. The coral colonies were collected from the Truman Annex site in Key West harbor where an existing seawall was demolished as part of an expansion project. Ten species were selected for fragmentation including Colpophyllia natans, Dichocoenia stokesii, Diploria clivosa, D. strigosa, Montastrea franksi, M. annularis, M. cavernosa, Porites asteroides, Siderastrea siderea, and Solenastrea bouroni.
In July 2004, the partners fragmented the corals, using a tile saw, into approximately 2.5 x 2.5 cm pieces, and using a 2-part epoxy, affixed these to a standardized cement base. Colonies were selected for fragmentation. Genetically identical colonies were preferred but not available for all species due to size of parent colony. Where multiple parent colonies were used, each facility received representative samples. 60 fragments of each species were made to allow for 20 fragments per culture facility. Coral fragments are being cultured for one year under 2 separate aquaculture conditions: 1) a greenhouse at the UF Tropical Aquaculture Laboratory in Ruskin, and 2) a live rock lease site operated by Ken Nedimyer off of Key Largo.
Fragments of coral will be restored to a selected site in the FKNMS. Growth and survival will be compared among corals from the different facilities to provide an economic cost-benefit analysis of culture techniques. The fragments have been measured with calipers and digital images were taken of each fragment with a scale bar before restoration. Fragments will be monitored and measured once a month for 12 months. In addition, a visual health assessment will be recorded, along with any mortality of test fragments.
Two primary questions remain concerning the feasibility and direction of using cultivated corals in coral reef restoration efforts: 1) will aquacultured corals become a vector for disease introduction when returned to a restoration site and 2) are survival and growth success of reintroduced fragments affected by culture techniques? The partners will conduct research to provide data and protocols to help answer these questions and improve coral restoration efforts. Establishing the health of coral fragments returned to the wild will help ensure that they do not become vectors for disease, increasing the safety of this promising technique for coral restoration.
Health Certification
Partners are currently developing protocols for health certification with NOAA and U.S. Dept. of Agriculture/Animal and Plant Health Inspection Service (USDA/APHIS). Health assessments of parent colonies were done at the time of collection. Fragments are being monitored in culture for visual abnormalities as known coral diseases are categorized by visual signs (Black Band disease, etc). Colonies showing signs of disease undergo: a detailed visual description, photos, live stereoscopic evaluation, microbiology and histological evaluation. To develop the list of diseases in cultured coral further, we are sending a Captive Coral Health Survey to other cultivating facilities.
Evaluation of handling methods, prophylactic treatments, biosecurity protocols, and problems will be used to develop a method for screening the population for health. Protocols for health certification will include history, visual inspection, water quality testing, and histological evaluation of aquaculture normals and diseased fragments. Additional diagnostics, as needed, will be developed for captive diseases when lesions are observed.
Restoration
After at least 12 months of culture and health certification, up to 5 representative fragments from 10 species from each facility will be selected to introduce to a restoration site in the FKNMS. The fragments will be monitored in the field for growth and survival for at least 12 months. Variations in growth, survival, and health among the 2 treatments will be statistically analyzed using an analysis of variance via Statistical Analysis System (SAS Institute, Cary, NC). Survival, growth, and health for each treatment will be separately evaluated for the year in culture and the year after restoration in situ.