Mathematical Modeling Describing the Effect of Fishing and Dispersion on Hermaphrodite Population Dynamics

Abstract

Abstract. In order to study the impact of fishing on a grouper population, we propose in this paper to model the dynamics of a grouper population in a fishing territory by using structured models. For that purpose, we have integrated the natural population growth, the fishing, the competition for shelter and the dispersion. The dispersion was considered as a consequence of the competition. First we prove, that the grouper stocks may be less sensitive to the removal of large male individuals if female population are totally protected. Second, we show that fishing does not disturb the demographic structure of the population. Finally, we prove that female selective fisheries have the potential of drastically reduce reproductive rates. We also prove that male fishing decreases competition and then increases the total population number.

Dynamical Behaviors in a Stage-Structured Model with a Birth Pulse

“…As the world's marine fisheries are struggling with the serious issue of overexploitation, direct overfishing poses a clear and present danger to their survival. It is highly realistic for decision makers to devise a workable scheme that sustains fisheries at a high level of productivity and meets economic needs [5,6]. There are two key factors in fisheries, namely, the effect of the seasonality and population stage-structure [7][8][9].…”