Vivek Thampi, Applied Mathematics, University of Waterloo
Modelling The Caribbean Coral Reefs Dynamics and the Impact of Parrotfish Exploitation Utilizing A Coupled Human-Environment System
The Caribbean coral reef ecosystem has had a long history of deterioration. The various ecological and anthropogenic stressors were thought to be mitigated by the presence of primary reef grazers, the Diadema Antillarum sea urchins. However, significant decimation of the population in 1983 has resulted in the ecosystem's increasing reliance on secondary grazers, parrotfish, in order to maintain the integrity of the coral reefs. Unfortunately, numerous setbacks, such as parrotfish exploitation and sedimentation, have dramatically perturbed the ecosystem into a state governed by invasive macroalgal growth. As such, mathematical modelling has been employed in order to determine strategies to promote conservation and regrowth of this ecosystem. In general, the incorporation of human influence into ecological models has been performed via the inclusion of a parameter, which remains unchanged based on the changes in the environment. In order to accurately capture the impact of human influence, coupled human-environment systems have been developed, coupling the effects of human behaviour under changes in the environment. Here, a previously established reef-ecosystem model has been modified into a coupled human-environment system to observe the effects of conservational strategies on the dynamics of Caribbean coral reef ecosystem. Results of model analysis reveal the impact of increased social norms, population alertness or sensitivity to the live coral cover, and parrotfish exploitation on the integrity of the ecosystem. From our results, the use of coupled human-environment systems has enhanced the parsimonious power of the model, providing potential opportunities for additional extensions in the future.