A Review of Size Dependant Survival During Pre-recruit Stages of Fishes in Relation to Recruitment

The theory of recruitment in fishes and hypotheses pertaining to causes of recruitment fluctuation are summarized. In spite of considerable research effort over several decades there has been no significant improvement in identifying clear causal mechanisms of recruitment in marine fish stocks. Starvation has not been demonstrated to be a primary mechanism controlling survival of fish larvae. Studies matching food levels and year-class strength continue to provide indirect evidence that growth during the first year of life is dependent on food supply and may be important in determining survival. The hypothesis that survival is a direct function of growth provides a rational theoretical framework for recruitment research and is suggested as a basis for future work. Growth rate must be studied as a function of both ration and temperature. Studies examining the relationship of growth rate to survival should be specific to each life history stage and ideally integrated throughout the pre-recruit period. It remains to be demonstrated that survival is a direct function of growth, mediated through size-dependent predation.