Recurring plankton bloom dynamics modeled via toxin-producing phytoplankton

A simple nutrient-phytoplankton model is proposed and analyzed in the presence of toxic chemicals released by the toxin producing phytoplankton (TPP) to understand the dynamics of seasonally recurring bloom phenomenon. We observe that the presence of toxic chemicals helps to explain the bloom phenomenon. We have further studied our proposed system under the influence of variation in the toxin liberation rate. We observe that our model displays a wide range of dynamical behaviours, from simple cyclical blooms to irregular chaotic blooms. We also observe the skipping phenomenon. We conclude that the effect of toxic chemicals released by TPP cannot be ignored in 'bottom-up' models.