A Novel Predator-Prey Modelling Approach to Survival Rate of Fish in an Unbounded Aquatic Environment

This paper presents a survival analysis of fish in an unbounded aquatic environment where fish, zooplankton and phytoplankton interact freely. we formulate a predator-prey model by incorporating optimal selective harvesting. From the numerical results, it is observed that as the selling price of unit biomass of fish and instantaneous time delayed annual discount rate increases, then the optimal harvesting rate of fish increases gradually. Therefore, the harvesting of fish species will be increased whenever the selling price of fish and the annual discount of fish production cost increases. It is also found that the optimal selective harvesting rate of fish decreases due to the increase on cost of harvesting of fish.