Modelling the interaction of two biological species in a polluted environment

In this paper a mathematical model is proposed and analysed to study the ef fect of an environmental pollutant on two interacting biological species. T he interaction between the two species is considered to be of three types, namely, competition, cooperation, and prey-predator. In each case criteria for local stability, instability, and global stability of the nonnegative e quilibria of the system are obtained. The effect of diffusion on the equili brium state of the system is also studied. (C) 2000 Academic Press.