Photosynthetically enhanced calcification has been studied in the hermatypic coral, Acropora cervicornis. The rate in the light is directly proportional to the intensity of illumination between 0 and 10500 lx. Sodium azide, sodium cyanide, 2,4-dinitrophenol (2,4-DNP), pentachlorophenol and carbonyl cyanide, m-chlorophenyl hydrazone (CCCP) inhibit light (i.e. photosynthetically) dependent rates. With the exception of sodium azide, this may be attributed to an inhibition of oxidative phosphorylation. Dark rates of calcification are unaffected by the addition of these compounds.