The oceans around southern Africa and regional effects of global change

In the last few decades, a great deal of work has been carried out on the n ature of the oceanic circulation around southern Africa. Attempts have been made to determine regional ocean-atmosphere interactions and the effect of changing sea-surface temperature fields on weather and climate. At the sam e time, the marine biology and ecosystems of coastal waters have been exten sively studied. Few studies have been concerned with the possible effects o f global change on the physical and biological components of the systems an d their linkages in the regional earth system of the subcontinent. In this paper, a first attempt is made to integrate past work and synthesize it usi ng a systems approach framework. Attention is focused on the nature of the regional ocean circulations affecting southern Africa. The features of the Agulhas and Benguela systems most likely to be affected by global change ar e discussed and contrasted. At the same time the links to the marine biolog ical and coastal ecosystems of the east and west coasts are explored and th e inter-dependencies between physical, biogeochemical and ecological compon ents of regional ocean systems and their anthropogenic modulation are consi dered.