The species diversity was quite low in both Skagerrak and Kattegatt, the only exception was the first sampling occasion at Anholt E. High densities of the calcium flagellate Emiliania huxleyi was recorded. This species normally appear in higher densities in late spring and early summer in this area. Different cells belonging to Prymnesiales (previously recorded as belonging to the genus Chrysochromulina) were found in high abundance and especially at N14 Falkenberg. The large diatoms Proboscia alata and Dactyliosolen fragilissimus were found in high cell numbers. The integrated (0-20m) chlorophyll a concentrations in both Skagerrak and Kattegatt were within normal for the season. The phytoplankton community in the Baltic Sea was in general dominated by ciliates, cryptomonads, Pyramimonas spp., Eutreptiella spp. and species from the class Prymnesiales. Aphanizomenon flos-aquae was mostly found in The Gotland Basin but only in moderate amount. The cell density was low but the species diversity was relatively high. The integrated (0-20m) chlorophyll a concentrations were within normal in The Baltic Sea.