CORAL HEALTH ASSESSMENT PROGRAM STUDIES

Acropora Growth Anomalies at French Frigate Shoals

G. Abeby and T. Work

Coral found with AGA.

Ten disease states for corals have now been reported from the Northwestern Hawaiian Islands, with two of those diseases, Acropora white syndrome (AWS) and Acropora growth anomalies (AGA), identified as diseases of concern. Permanent sites were established in 2005 at French Frigate Shoals (FFS) to investigate these diseases with field and laboratory studies to determine the character, ecology and causes of the disease.

AGAs are a widespread disease occurring at 4 of the 5 permanent sites (80%) at FFS. At one of the permanent sites there is an extreme clustering of affected colonies, which has been termed “tumor city”. Within the area, the prevalence of AGAs was 40.2% in 2005 and 31.1% in 2006. In addition “dead zones” were documented within “tumor city” where numerous entire intact coral colonies with growth anomalies were dead. This suggests that the chronic energy drain growth anomalies place on coral colonies can ultimately result in the death of the colony. The extreme clustering of GAs, both within colonies and on the reef, suggests that an infectious agent could cause this disease. Clearly, more research is needed in understanding the disease and thus allowing management decisions to be made based on the best available science.

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