The impact of fear and harvesting on plankton-fish system dynamics incorporating harmful phytoplankton in the contaminated environment

Abstract

In this study, an aquatic system with fish, zooplankton, and harmful phytoplankton interacting with one another through the food chain in a polluted environment was proposed. It was thought about how the dynamics of the food chain were affected by fear and harvesting. An alternate food source was included for fish to eat to make the model more realistic. The characteristics of every solution were investigated. Both a local and global analysis of the system's stability was conducted. The system's persistence was investigated. The effects of changing the system's parameters were investigated using the local bifurcation theorem. To validate the discovered theoretical result and comprehend the effect of the system's parameters, a numerical example was then provided. It has been found that the system responds very quickly to changing the parameter values and exhibits a variety of attractors, including stable limit cycles and bi-stable behavior.