Microalgal primary producers and their limiting resources

In this thesis, it was demonstrated that the phytoplankton community in the Marsdiep basin of the western Dutch Wadden Sea was influenced by a variety of abiotic factors. Phosphorus (P) was a main limiting factor during the spring bloom which lasted until May and this had a strong influence on the phytoplankton biomass and composition. It became also clear that dissolved organic phosphorus (DOP) needs to be better characterized in order to understand its source of P for phytoplankton growth. Lastly, microphytobenthos (MPB) primary production needs to be included in future monitoring programs of the Wadden Sea because it will give a better understanding of the carrying capacity of this environment and bottom up regulation of higher trophic levels.