Abstract
The seasonal intensity of wind-induced coastal upwelling in the Indian Ocean is investigated. The upwelling off North Somali stands out as the dominant upwelling features in the region, producing by far the strongest seasonal upwelling pulse that exists as a regular feature in any ocean on our planet. It is surmised that the productive pelagic fish habitat off Southwest India may owe its particularly favorable attribute to coastal trapped wave propagation originating in a region of very strong wind-driven offshore transport near the southern extremity of the Indian Subcontinent. Effects of relatively mild austral summer upwelling that occurs in certain coastal ecosystems of the southern hemisphere may be suppressed by the effects of intense onshore transport impacting these areas during the opposite (SW Monsoon) period. An explanation for the extreme paucity of fish landings, as well as for the unusually high production of oceanic (tuna) fisheries relative to coastal fisheries, is sought in the extremely dissipative nature of the physical systems of the region. In this respect, it appears that the Gulf of Aden and some areas within the Mozambique Channel could act as important retention areas and sources of 'Seed stock' for maintenance of the function and diversity of the larger regional biological ecosystems.