Population-level effects of density dependence in a size-structured fishery model

摘要

A discrete size-structured fishery model is derived to study the population-level effects of the timing of density dependence. The inherent net reproductive number of an individual is the same if the population is assumed to be identical in every way except the occurrence of intraspecific competition. However, total population size may grow without any restriction if density dependence occurs at the second or the third size class. Data of red snapper with Beverton–Holt and Ricker nonlinearities are simulated to make further comparisons. The numerical study indicates that while the population is more resilient if density dependence occurs at the first size class the equilibrium size is larger if density dependence occurs at the second size class.