Lesion Regeneration Rates in Reef-Building Corals Montastraea Spp. as Indicators of Colony Condition
Regeneration rates of coral lesions reflect the ability of colonies to repair damage and therefore can be useful indicators of coral health and environmental conditions. We quantified regeneration rates of boulder corals Montastraea spp. at four, 6 m deep patch reefs within Biscayne National Park (BNP) and the upper Florida Keys National Marine Sanctuary (FKNMS), and along a 3 to 18 m depth transect in FKNMS. Coral lesions (approx. 2 cm 2 ) created during sampling for cellular-diagnostic analysis were monitored quarterly in 2001 and 2002, and in February 2003. Regeneration was a dynamic process, continuing longer than previously reported (>300 d after lesion formation). Geographic location was the strongest factor affecting regeneration rate at our study sites. Lesion regeneration differed significantly among 6 m deep sites; sites offshore from John Pennekamp Coral Reef State Park (Algae Reef and White Banks) consistently had the highest regeneration rates, with colonies exhibiting exponential declines in lesion size and a high percentage of completely healed lesions. Along the depth gradient, corals at the 3 m site regenerated significantly faster than corals at 6, 9, and 18 m. These results suggest that corals sampled at FKNMS 6, 9 and 18 m sites and BNP were in poor physiological condition or were exposed to suboptimal environmental conditions, as evidenced by highly variable and overall low regeneration rates, a low percentage of healed lesions, and a high occurrence of breakage or Type II lesions (lesions that increased in size by merging with areas of denuded tissue on the colony).