Mathematical Modeling of Macroalgae-Borne Pathogen Transmission in Corals

Competition between macroalgae and corals for occupying the available space in the seabed is an important ecological process underlying coral reef dynamics. Several benthic macroalgae species produce allelopathic chemical compounds that hinder the settlement and survival of coral larvae. The release of allelochemicals by harmful macroalgae helps the microorganisms associated with corals in delivering pathogens. Aside from this, the proliferation of macroalgae in coral reefs brings about expanded actual contacts among corals and macroalgae, setting off coral infection. The infected coral class along with the abundance of macroalgae changes the community structure toward macroalgae-dominated coral reef ecosystem. We investigate the dynamics of coral reefs in the presence of macroalgal allelopathy and microbial disease in corals by proposing an eco-epidemiological model under the assumption that the transmission of infection happens through free-living pathogens in the environment. We analyze the model and found that the system is capable of exhibiting the existence of a transcritical bifurcation and a Hopf bifurcation due to the changes in some model parameters.