Herbivore harvesting and alternative steady states in coral reefs

Autor: Joydeb Bhattacharyya, Ikbal Hossein Sarkar, Samares Pal
Rok vydání: 2020
Předmět:
Zdroj: Applications of Mathematics. 66:233-268
DOI: 10.21136/am.2020.0338-19
Popis: Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Degradation of coral reefs is often associated with changes in community structure towards a macroalgae-dominated reef ecosystem due to the reduction in herbivory caused by overfishing. We investigate the coral-macroalgal phase shift due to the effects of harvesting of herbivorous reef fish by means of a continuous time model in the food chain. Conditions for local asymptotic stability of steady states are derived. We have shown that under certain conditions the system is uniformly persistent in presence of all the organisms. Moreover, it is shown that the system undergoes a Hopf bifurcation when the carrying capacity of macroalgae crosses certain critical value. Computer simulations have been carried out to illustrate different analytical results.
Databáze: OpenAIRE