Fang, L.-S., Huang, S.-P. and Lin, K.-L. 1997. High temperature induces the synthesis of heat-shock proteins and the elevation of intracellular calcium in the coral Acropora grandis. Coral Reefs 16: 127-131.
What was done
The authors studied the production of several stress-induced proteins in coral cells that were subjected to elevated temperatures.
What was learned
One of the heat-shock proteins produced by the coral Acropora grandis was heme oxygenase.
What it means
Several researchers have suggested heat-shock as a primary cause of coral bleaching. However, heme oxygenase is also induced by high levels of UV radiation, so its presence is not a sure indicator of heat stress alone.
The authors also note that the thermotolerance of an organism can be enhanced by the production of heat-shock proteins, "thereby increasing its ability to survive under unfavorable environmental conditions." In a real-world example of this phenomenon, they cite the case of Acropora grandis samples taken from the hot water outlet of a nuclear power plant near Nanwan Bay, Taiwan. In 1988, the year the power plant began full operation, the coral samples were bleached within two days after exposure to temperatures of 33°C. By 1990, however, they report that "samples taken from the same area did not even start bleaching until six days after exposure to 33°C temperatures."
Reviewed 1 April 1999