The Involvement of Calcium in Heat-induced Coral Bleaching
Shiao-Ping Huang, Ku-Lin Lin and Lee-Shing Fang (1998) Coral bleaching is inducible by elevated sea water temperature. At the subcellular level the mechanism of bleaching is unclear. We investigated the relationship between intracellular calcium concentration and bleaching induced by elevated temperature. Intracellular calcium concentration rose in proportion to the duration of heat treatment. Bleaching was inhibited after applying the calcium chelator EGTA and the cation ionophore A23187 to deplete extra- and intracellular calcium concentrations. Further, heat-induced coral bleaching was inhibited when the ambient calcium concentration in sea water was reduced or depleted. The extent of bleaching was correlated with the calcium concentration of the sea water. These findings indicate that calcium plays a pivotal role in the subcellular mechanism of coral bleaching.
Keywords
Coral bleaching, Calcium concentration, Exocytosis.
