ABSTRACT
Population demography is based on simple models for constructing life tables from reproductive and mortality parameters or on age-based models using Leslie matrices. Stock assessment of harvested species for fishery management require more complex model and data requirements to account for density-dependent mechanisms for population regulation (Wood et al. 1979; Walker 1992), somatic growth and trends in abundance of the animals, and history of extracted catches by the fishery (Punt and Walker 1998). Some fishery assessment models also account for complex interactions between the animals and the fishing gear, movement of the a;'mals, and stock structuring (Punt et a/. 2000).
