SPREAD OF A BLACK-BAND DISEASE EPIZOOTIC THROUGH THE CORAL-REEF SYSTEM IN ST-ANNS-BAY, JAMAICA

The distribution, abundance and dispersion patterns of black-band dise ase (BBD) [Phormidium corallyticum (Cyanobacterium)] were determined o n four shallow reefs located on the north coast of Jamaica. Between Ja nuary 1992 and August 1993, 5.2% of the total population of massive co rals, including the dominant reef-building species Diploria clivosa, D , strigosa, Montastrea annularis, M. cavernosa and Siderastrea siderea , became infected within 20 sites (6280 m(2) total area). Black-band d isease was first identified in the back reef; over 19 mo, the abundanc e of BED increased dramatically, and infections spread 3 km in the dir ection of the predominant current. The distribution of diseased corals appeared to be clumped with infections progressing from one individua l to adjacent corals which were attached by contiguous skeleton but un connected by live tissue. Black-band disease occurred on 8.6% of the S . siderea colonies; this species was impacted by excessive run-off ass ociated with abnormally high rainfall. In contrast, M. annularis, the coral reported to be most susceptible to the disease, had a lower freq uency (2.2%) of infection. Migration of a black-band disease epizootic across a coral reef has not been previously documented.