Traditional yield models have gained recognition as generally reliable 'or describing population demographic processes over a spectrum of temperate sea fish life history classes. The models have embedded within them assumptions regarding constant parameterization and low to nonexistent population interaction. However, population pressures may be more important determinants of fish stock abundance in tropical multispecies environments. Several investigators have demonstrated that intra-specific density-dependence may be a prevalent feature of natural populations. There is insufficient quantitative knowledge about functional relationships such as the manner in which demographic characteristics of a given species change with population density. The dynamical behavior of most natural populations is likely to be influenced by their interactions with various age strata of the same species or with interactions with other species.