ECOPHYSIOLOGY OF MARINE FISH RECRUITMENT: A CONCEPTUAL FRAMEWORK FOR UNDERSTANDING INTERANNUAL VARIABILITY

Present data and our application of logic do not permit confident rejection of the null hypothesis: Interannual variation in recruitment of marine fishes (typified by certain flatfishes) is independent of ecophysiological factors. Our inability to reject this hypothesis reflects not its likely validity, but rather a lack of conceptual structure and appropriate data for realistic evaluation of alternative hypotheses. Therefore, in this paper, we set aside as presently intractable the problem of understanding in any generalizable way the specific effects of environment on interannual variation in marine fish recruit-ment. Instead, we return to a conceptual scheme first proposed almost 50 years ago by F.E.J. Fry for considering effects of environmental factors on the physiology of fishes. We first extend this scheme to population-level responses, including recruitment, and then even further, to community/ecosystem-level responses. Fry supposed that all of environment can be resolved into five classes of physiologi-cal effects-controlling (which set the pace of metabolism), limiting (which constrain maximum metabolism), lethal (which completely interdict metabolism), masking (which increase obligatory met-abolic work), and directive (which release and unload metabolism by guiding enviroregulatory responses). We suggest that corresponding effects can be recognized at the levels both of populatio