A CORAL-CoTS SYSTEM FOR THE INFLUENCE OF ENVIRONMENTAL FACTORS ON THE CORAL GROWTH

This paper investigates a coral reef system involving corals and crown-of-thorns starfish (CoTS), with the inclusion of environmental factors and stochastic environmental fluctuations. Stochastic disturbances are described by the mean-reverting Ornstein–Uhlenbeck process, while environmental factors cover light intensity, wind, water pH and global warming. Such considerations make the model dynamics more realistic. We analyze the deterministic coral-CoTS model in terms of permanence, stability and Hopf bifurcation, and carry out a sensitivity analysis on key parameters. The corresponding stochastic model is then studied, focusing on ergodic stationary distributions, persistence in the mean and stochastic extinction. These theoretical results lay a foundation for numerical simulations. Numerical analysis shows that environmental factors and stochastic fluctuations significantly affect coral-CoTS dynamics. In particular, reduced light intensity can eliminate wind-induced periodic solutions and cause the extinction of corals and CoTS, while increased light intensity tends to destabilize the system.