The impacts of prey harvesting activity on the stability of an extreme fishery system with prey carrion biomass resources

Abstract

This research analyzes the interaction of prey and carnivorous apex facultative scavengers in the existence of prey carrion biomass. Prey consists of vertebrate marine animals as the main food preferences for carnivorous apex facultative scavengers, which comprise fish, reptiles and marine mammals, whose carrion is also hunted and eaten. Apex facultative scavengers or formidable predators are superior in scavenging, where they can search and consume carrion more efficiently than other scavengers. The fishery system is assumed to be in an extreme condition where the temperature in marine life habitat is high due to climate change. There, the survival of apex facultative scavengers in the marine system only depends on their predation and scavenging interactions with prey and prey carrion biomass, respectively. Moreover, prey carrion biomass formation only relies on the predation interaction of prey and apex facultative scavengers due to its limited source. Apex facultative scavengers can be extinct without the existence of prey. Both prey and apex facultative scavenger populations are harvested due to their commercial values. However, the dynamical behaviors of the fishery model have been analyzed by considering prey harvesting as a bifurcation parameter due to their importance in determining the stability of an extreme fishery system since prey are the main source of apex facultative scavengers growth and prey carrion biomass formation. It is found that the underharvesting of prey leads to the appearance of periodic oscillations around unstable coexistence equilibrium through Hopf bifurcation. The intermediate level of prey harvesting guarantees the coexistence of all interacting populations, and their high level of harvesting implies the appearance of the bistability phenomenon and saddle-node bifurcation of the steady-states in the fishery system. Lastly, the overharvesting of prey makes the extreme fishery system collapse.