This directory contains the tex files and my Master's thesis for the Theoretical Physics degree. Following the works by Huisman et al., an alternative, stochastic model is considered to model the phytoplankton growth in blooming conditions (i.e. non-limiting nutrients), with an emphasis on the light-driven growth of new cells. The code I developed can be found at https://github.com/GabrieleLabanca/stochastic_plankton. Other code, developed by the research group and thus not public, concerns the solution of Navier-Stokes equations to model the transport of plankton; some code used for the analysis of the results is found at https://github.com/GabrieleLabanca/turbolag_util.