How does mixotrophy impact ecosystem structure and biogeochemical cycles in the global ocean? We examine the biogeochemical consequences of mixotrophy and omnivory in the emergent food webs of global ocean simulations of circulation, elemental cycles and planktonic ecosystem. The simulations resolve many tens of planton phenotypes with key traits, including nutrient affinities and predator-prey interactions, structured by body size and membership of key taxonomic (functional) groups.
Idealized simulations comparing an ecosytem with obligate photo-autotrophs and heterotrophs to one with universal mixotrophy suggest that mixotrophy modifies ecosystem function by increasing average body size, photosynthesis in larger size classes and export of sinking organic material. Extending the model to resolve key taxonomic groups we impose the key trait of the dinoflagellate-analogs to be phagotrophic mixotrophy. We will discuss the emergent regional and seasonal biogeography of dinoflagellate-analogs in the light of observations including the Continuous Plankton Recorder survey and the Atlantic Meridional Transect. Initial examination reveals that the model captures observed meridional patterns in diversity within and between groups.