Predator-prey fishery model under deterministic and stochastic environments: a mathematical perspective (Q1930634)

Summary: We study a predator-prey fishery model with ratio-dependent functional response under deterministic and stochastic environments. Prey and predator populations are continuously harvested following the CPUE (catch-per-unit-effort) hypothesis. Mathematical results like positive invariance, dissipativeness, stability of equilibria and permanence of the system have been established. The dynamics of the zero equilibria have been thoroughly investigated to find out conditions under which trajectories starting from the domain of interest can reach the origin following any fixed direction. Computer simulations have been carried out to illustrate different analytical findings. Our results indicate that the system may exhibit different kinds of bistabilities depending on the harvesting effort and initial population densities. Investigation also reveals that exploited marine fish populations can exhibit steady, cyclic or irregular behaviour.