First records of coral disease and tumors on Hawaiian reefs

Hunter, Cynthia

A variety of methods were used to quantify the distribution and temporal progression of tissue necroses and tumors on coral colonies at three sites in Hawai‘i. Distribution and abundance of diseased tissues were recorded as well as changes in overall coral and algal abundance through the analysis of permanent macrophotography stations and video transects of survey areas. The incidence and extent of necroses, as well as the amount of algal turf-covered surface area, increased with increasing colony size; the incidence of tumors on coral colonies was independent of colony size. Both coral necroses and tumors usually led to the loss of coral tissue, although recovery and regeneration sometimes occurred from the edges of healthy tissue with time. Mean coral and algal abundance varied within and among sites, as well as through time. Coral cover declined by 10% during the seven-year period of this study (1991-1998) at Hanauma Bay, Oahu and Honolua, Maui, with a concomitant increase in turf algae. Coral cover increased during the same period at Puako, Hawai‘i, while mean algal cover decreased. Incidence of diseased tissues initially declined between 1991 and 1993 censuses at Hanauma Bay and Honolua and has remained relatively constant at all sites from 1993 to 1998. These studies provide the first documentation of disease and tumors in Hawai‘i.