Dynamics of phytoplankton-zooplankton systems with toxin producing phytoplankton

We propose periodic systems of phytoplankton-zooplankton interactions with toxin producing phytoplankton to study the effects of TPP upon extinction and persistence of the populations. Using the concept of uniform persistence, it is proved that the two populations can coexist for certain parameter regimes. The numerical investigation demonstrates that toxin producing phytoplankton may promote survival of zooplankton population on one hand and may destabilize the interactions on the other hand. Moreover, passive diffusion of both populations can simplify the dynamics of the interactions and exhibit plankton patchiness.