Coral Reef Diseases

There are a number of coral diseases documented world-wide. Coral reef ecosystems which are chronically stressed due to both natural and anthropogenic (human-caused) sources can cause them to be more susceptible to various diseases. A variety of pathogens are threatening essential reef organisms such as hard corals, gorgonians (soft corals), sponges, and coralline algae. For example, White Band Disease is a bacterial infection which specifically effects Acropora spp. (healthy Acropora spp. shown below). White Band Disease spreads along the branches of Acropora spp., from base to tip, inevitably killing entire colonies. Furthermore, scientists have identified a pathogen of terrestrial origin causing a fungal infection in Caribbean sea fans (two sea fan species shown below).

 

 

 

Coral reef ecosystems have been significantly impacted by diseases affecting organisms other than corals. The prime example being a pathogen causing the mass mortality of Diadema antillarum (long-spined sea urchin, pictured below) throughout the Caribbean in 1983. Scientists have observed some diseases spreading quicker when the hosts are continuously stressed by high temperatures and numerous sources of pollution.