Are there useful life history indicators of stock recovery rate in gadoids?

Abstract

Age at maturity is one of the key variables determining the maximum rate of population growth and so may be a good indicator of stock recovery potential. Spawner age composition may also affect the probability of high recruitment and so could be relevant to stock recovery. This study examined the relation between early survival, age at maturity, and the demographic composition of spawners in many cod and haddock stocks. Reported measures of fecundity and maturity were used to estimate total egg production for comparison with numbers at age 1 and age at 50% maturity. The instantaneous rate of population growth (r) was estimated for cohorts from life history tables during periods when spawning biomass was depleted (e.g.