Elkhorn Coral

Distribution

Elkhorn coral exist in the Caribbean, the Bahamas, and Florida Keys. Its range reaches as far north as Biscayne National Park, Florida and as far south as Venezuela. However, it has been suggested that as a result of climate change, the range of elkhorn coral has expanded northward along the Florida Peninsula and into the northern parts of the Gulf of Mexico.

Elkhorn coral are found primarily in shallow waters with temperatures between 26 to 30 °C , and with significant water movement. They are one of the most abundant species in waters ranging from 1 to 5 metres deep, and a few colonies have been reported from waters as deep as 20 metres .

Status

There have been several efforts to conserve the Elkhorn coral which have had mixed results. The Florida Keys National Marine Sanctuary has served as a protected region for the area’s coral species. The Florida Keys National Marine Sanctuary has also developed plans for the protection and restoration of elkhorn coral. Restoration efforts have included attempts to re-attach coral fragments that were broken off during hurricanes or by ships. Attempts to re-attach coral fragments have also occurred in Puerto Rico and the Virgin Islands but all have had limited success.

Attempts are also being made to conserve the coral by culturing coral fragments. The Florida Keys National Marine Sanctuary, the National Oceanographic and Atmospheric Administration, and Mote Marine Laboratory all are having limited success with coral nurseries in the Florida Keys and Puerto Rico.

The National Oceangraphic and Atmospheric Administration has developed and tested several ecological methods to restore this coral. These methods include removing coral predators and reintroducing herbivores to the ecosystems to feed on harmful algae that grows on the coral.

In 2004, the Center for Biological Diversity requested the National Marine Fisheries Service placed elkhorn coral on the endangered species list. In 2005, NMFS decided that elkhorn coral qualified as an endangered species under the Endangered Species Act of 1973. On May 4, 2006 Elkhorn coral and Staghorn coral were officially placed on the Endangered Species List.

Predators

Elkhorn coral was once one of the most abundant species of coral in the Caribbean and the Florida Keys. Since 1980 it has been estimated that 90-95% of elkhorn coral has been lost. Threats to elkhorn coral 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 there are so many inhibitors to its survival.

Diseases that affect elkhorn coral include white pox disease, white band disease, and black band disease. White pox disease is a disease that only affects elkhorn coral. It 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 square centimetres per day but can cause as much tissue loss as 10.5 square centimetres 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 , 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.