A mass of black water containing noxious organic material swept through Laurel Bay last year  Some scientists believe that this event was a naturally occurring but infrequent phenomenon  The black water completely wiped out five species of coral in the bay, including mounds of coral that were more than two centuries old
Ttherefore, even if this black water phenomenon has struck the bay before, it did not reach last year' s intensity at any time in the past two centuries
Older specimens of coral in the bay were more vulnerable to damage from the influx of black water than were young specimens.