Seasonal dynamics of Tripos-species in Oslofjorden

The genus Tripos contains large thecate dinoflagellates that are important primary producers in Oslofjorden, especially in late summer and during the fall. Sometimes they form blooms and color the water red. Because of their large size they may contribute significantly to the total phytoplankton biomass even when they do not bloom. The genus comprises more than 100 species worldwide and about 10 are recorded from Oslofjorden. Many of the Tripos-species occurring in Oslofjorden are readily identified while a few are difficult to discern. Thecate dinoflagellates are covered with cellulose plates that are used for their identification. They have a sexual life cycle and gametes of some species are very similar to the vegetative stage of other species. The project aims at elucidating the importance of Tripos-species within the phytoplankton