A prediction of some possible effects of thermal pollution on marine organisms on the west coast of South Africa with particular reference to the rock lobster jasus lalandii

The nuclear power station, which ESCOM proposes to build on the coast near Cape Town, will be cooled by sea water and will cause the temperature of the water in the immediate vicinity of its outfall to be increased by about 6°C. Experiments were conducted in an attempt to predict the biological effects of the increased temperature. Particular attention was paid to those organisms, such as kelp and mussels, which dominate the local kelp-bed ecosystem and to those such as the rock lobster which are of particular commercial importance. The effects of increased temperature on such parameters as growth rate, fecundity and spawning period were examined, and it was concluded that in many cases the higher temperature would be detrimental. Some of the possible over-all effects on the entire kelp-bed ecosystem are discussed.