An individual-based model for studying the aggregation behavior in phytoplankton

In this paper, we use an individual-based model (IBM) in order to study the aggregation of phytoplankton cells. The model describes the movements of cells and also the cells’ division and their death. The movement of a phytoplankton cell is based on an Itô stochastic differential equation with a drift term describing the spatial interactions of the phytoplankton cell with the other cells in the system and a dispersion term representing the cell diffusion. The demographical process is described by the mean of a branching process. We simulate the IBM model and present some particle pictures showing the spatial structure of the phytoplankton cells. We focus on the effects of the different processes involving at the level of the phytoplankton cell (diffusion, spatial interactions, branching) on the spatial distribution of the phytoplankton to help the understanding of the aggregation phenomenon in phytoplankton.