Effect of enrichment on plankton dynamics where phytoplankton can be infected from free viruses

Abstract

Most of phytoplankton species are subjected to viral infection and the viral infection could be a factor regulating phytoplankton community structure and primary productivity in the oceans. Mode of viral transmission is an important issue in biological point of view while modeling plankton dynamics in the presence of highly abundant free viruses. In this paper we formulate a simple predator-prey model with a viral infection in prey. We assume that the phytoplankton population can be infected by external free viruses following saturating functional form. Our results suggest that the nutrient enrichment can decline disease prevalence and the infection disappears if the nutrient enrichment is above a threshold value. However virus replication and half saturation constant of viral infection also play an important role in persistence of infection.