Marine phytoplankton represents the basis of the marine food web and plays as a biological pump an important role within the global carbon cycle. The Helmholtz Young Investigators Group PHYTOOPTICS, a cooperation between the Alfred-Wegener-Institute for Polar and Marine Research (AWI, Climate Sciences) and the Institute of Environmental Physics at the University of Bremen (IUP) <http://www.iup.uni-bremen.de/> aims at improving estimates of marine primary production by retrieving new biooptical information from the European satellite SCIAMACHY in addition to using the data of the common ocean colour sensors. The methods include besides developing remote sensing retrievals and models to calculate radiative transfer and primary production, also measuring in-situ biooptical and biogeochemical parameters of phytoplankton and light conditions during various ship cruises.