ABSTRACT
A large number of measurements of primary production have indicated that the areas richest in marine resources are normally those which have a high rate of primary production, even if it is sustained for comparatively limited periods. Oceanic waters are the least productive of all marine ecosystems. Hermatypic corals are stenotypie and are limited to warm saline waters, essentially between the tropics of Cancer and Capricorn, where the water temperature does not fall lower than 18°C. Along the west coast of India biological productivity of the shelf waters, at different major trophic levels, has been fairly well investigated and productivity rates have been correlated with the pelagic and demersal fisheries. G. G. Marten and J. J. Polovina summarize the maximum sustainable yields of pelagic and multispecies demersal fisheries in tropical coastal waters. Based on their overall biological productivity, marine ecosystems can be ranked, in terms of their exploitable resources: coastal upwelling areas, estuaries, coral reefs, shelf waters, mangroves and open ocean.
