Please see the current site for material released since that date. Contact us with any questions about finding information. Studies have shown that coral diseases are affecting greater numbers of coral species, are increasing in frequency and distribution, and are spreading to new regions faster than ever recorded in the past. In recent years, there has been an emergence of newly described coral diseases with new types of pathologies or tissue conditions not observed in the past. Several of these diseases also have been recorded as killing coral tissue at rates much faster than ever observed.
Coral diseases occur in response to biotic and abiotic stresses.
Biotic stresses are instigated by microorganisms including bacteria, fungi, viruses, and protozoans. Abiotic stresses occur in response to physical or chemical stresses, such as increased sea surface temperatures and UV radiation, anthropogenic input of nutrients, sediment, and other pollutants. Abiotic stresses may exacerbate the role of microorganisms in disease processes. Thus, the recent emergence of disease in corals is believed to be a consequence of deteriorating water quality that favors the proliferation of microorganisms, or of a reduced ability of a coral to defend itself against biotic and abiotic stresses. Most diseases appear to be a response to multiple factors.