On non-selective harvesting of two competing fish species in the presence of toxicity

The present paper deals with the problem of combined harvesting of two competing fish species, each of which obeys the law of logistic growth and releases a substance toxic to the other. The dynamical behaviour of the exploited system is examined. The possibility of existence of a bionomic equilibrium is discussed. The optimal harvesting policy is studied from the view point of control theory. Finally, some numerical examples are taken to illustrate the results.