The paper brings together major inferences from: (1) classical limnology—lake and stream typology, the role of major abiotic variables; (2) fisheries limnology—Ryder's morphoedaphic index, Jenkins' reservoir findings, concepts of habitat niches; (3) studies of ecological structure of communities—succession, diversity, stability, variability, regulation; (4) recent developments concerning the effects of major cultural stresses on fish communities. A model is proposed to interrelate these and other concepts, and then relate them all to conventional fisheries practices and objectives. The model is directed at events and processes at the community level of organization and it is argued that much of fisheries theory and management practices of the future will perforce need to be directed at the community level.