Author(s): Andrew W Bruckner, Ernest H Williams
The distribution, abundance and dispersion patterns of black-band disease (BBD) [Phormidium corallyticum (Cyanobacterium)] were determined on four shallow reefs located on the north coast of Jamaica. Between January 1992 and August 1993, 5.2% of the total population of massive corals, including the dominant reef-building species Diploria clivosa, D. strigosa, Montastrea annularis, M. cavernosa and Siderastrea siderea, became infected within 20 sites (6280 m2 total area). Black-band disease was first identified in the back reef; over 19 mo, the abundance of BBD increased dramatically, and infections spread 3 km in the direction of the predominant current. The distribution of diseased corals appeared to be clumped, with infections progressing from one individual to adjacent corals which were attached by contiguous skeleton but unconnected by live tissue. Black-band disease occurred on 8.6% of the S. siderea colonies; this species was impacted by excessive run-off associated with abnormally high rainfall. In contrast, M. annularis, the coral reported to be most susceptible to the disease, had a lower frequency (2.2%) of infection. Migration of a black-band disease epizootic across a coral reef has not been previously documented.