The Challenges of Incorporating Realistic Simulations of Marine Protists in Biogeochemically Based Mathematical Models

Protists are key components of marine microbial communities and hence of the biogeochemical mathematical models that are used to study the interaction between organisms, and the associated cycling of carbon and other nutrients. With increased computing power, models of microbial communities have markedly increased in complexity in the last 20 years, from relatively simple single nutrient currency, nutrient-phytoplankton-zooplankton-detritus (NPZD) models to plankton functional type (PFT) or trait based models of multiple organisms, or individual based models (IBMs) of specific organisms. However, our recognition, if not parameterisation, of the physiological processes that underpin both autotrophic and heterotrophic protist nutrition and growth arguably have increased faster than our modelling capability, generating a wealth of new modelling challenges. This paper therefore reviews historical development, current capability, and the future directions and challenges in protist based mathematical modelling