Mortality rates of scleractinian corals before and during a mass bleaching event

Abstract

Mass bleaching of shallow-water corals was observed at Lizard Island [Australia] and at other locations on the Great Barrier Reef in early 1982. In a patch-reef community at Lizard Island, mortality rates of scleractinian corals from 4 families were higher during the period of bleaching than during the previous year. It is postulated that bleaching may be the result of penetration of high levels of UV radiation during the time of maximum annual water temperature. Mortality rates varied among the coral species studied, and they were generally higher in smaller colonies. The coral mortality rates recorded are comparable with those reported in similar studies of reef-flat and reef-crest habitats.