Condition of coral reef cnidarians from the northern Florida reef tract: Pesticides, heavy metals, and histopathological examination

Abstract

Scleractinian corals and octocorals from two reefs within Biscayne National Park off southeast Florida were compared with respect to 1. relative abundances, 2. gross field condition, 3. concentrations of pesticides and heavy metals, and 4. histopathological condition. The northernmost reef, Bache Shoal, is near a large urban area (Miami) and potentially receives pollutants from this source. The southernmost reef, Alina's Reef, is less likely to be influenced by runoff from Miami, but may receive runoff from an important agricultural centre (Homestead). No consistent differences between the two coral reef communities were found; however, high frequencies of blemishes and abnormalities (bite marks, unusual growth forms, bleached tissues), tissue necrosis, and invading pathogens were evident at both sites. Additionally, high levels (to ppm) of organochlorine pesticides (lindane, heptachlor/heptachlor epoxide, α/γchlordane, and DDT residues) and heavy metals (As, Cu, Pb) were detected in several of the reef coelenterates from both sites.