Overall the phytoplankton diversity was low at the Skagerrak sampling sites. The genus Ceratium that has been found in high amounts during autumn was observed with moderate cell numbers. The species diversity was a bit higher at the Kattegat sampling sites compared to the Skagerrak area, except on the second sampling occasion at Anholt E. Dinoflagellates were the most common among the larger species and the genus Ceratium was found with relatively high cell numbers. The Baltic phytoplankton stations were dominated by small cells such as cryptomonads, mainly from the genus Teleaulax. The genus Chrysochromulina was present at all stations. Filamentous cyanobacteria were present at most stations and the genus Dinophysis at some. The integrated (0-20 m) chlorophyll a concentrations were low, but within normal for this month in all sampling areas.