Elkhorn Coral - Threats

Threats

Elkhorn coral was once one of the most abundant species of coral in the Caribbean and the Florida Keys. Since 1980, an estimated 90-95% of elkhorn coral has been lost. Threats include disease, coral bleaching, predation, climate change, storm damage, and human activity. All of these factors have created a synergistic effect that greatly diminishes the survival and reproductive success of elkhorn coral. Natural recovery of coral is a slow process, and may never occur with this species because so many factors inhibit its survival.

Diseases that affect elkhorn coral include white pox disease, white band disease, and black band disease. White pox disease, which only affects elkhorn coral, is caused by a fecal enterobacterium, Serratia marcescens. The disease is very contagious and commonly moves from one colony to its nearest neighbor. White pox creates white lesions on the coral skeleton and results in an average tissue loss of 2.5 cm2 (0.39 sq in) per day, but can cause as much tissue loss as 10.5 cm2 (1.63 sq in) per day. White band disease and black band disease have also greatly reduced the abundance of elkhorn coral. Diseases are one of the major causes of coral mortality, however, they are not well studied or understood.

Predators of elkhorn coral include coral-eating snails (Coralliophila abbreviata), polychaetes such as the bearded fireworm, and damselfish. Predation by these organisms reduces the corals' growth and ability to reproduce. Predation can eventually lead to the death of the coral colony.