Plankton Dynamics in Nutrient-Phytoplankton-Zooplankton Model with Viral Infection in Phytoplankton

Abstract

Present paper deals with a nutrient-phytoplankton-zooplankton model with viral disease in phytoplankton species. We have worked out some threshold conditions for extinction of the species. We have derived out the condition for existence of equilibrium points and their stability. We have explained the basic reproduction number and we analyzed the the community structure by the help of these basic repro- duction number. We also derived the condition of Hobf Bifurcationand persistence of the system. To observe the global dynamics we
have performed the extensive numerical simulations. Our Simulation results shows that viral infection is responsible for limit cycle plankton oscillations. It is also observed that nutrient may play important role
for controlling diseased induced plankton osciilations. Our numerical studies clearly indicate that viral infection is responsible for zooplank-ton survival as well as plankton oscillation dynamics. It is also implied that there a nutrient threshold is required for plankton oscillations as well as zooplankton survival. Nutrient threshold value is changed bynthe variation of viral infection in phytoplankton population.