This book was first published in 1979. If we are to improve our control and conservation of the food resources of the oceans of the world it is particularly important to increase our understanding of the basic mechanisms that control the abundance, distribution and production of marine organisms. The Productivity Marine (PM) section of the IBP filled an important role in concentrating international effort on specific problems of production, ecosystem structure and function, aquaculture, and the effects of mankind upon the marine environment.