Summary
A more autumn like phytoplankton community with more dinoflagellates was observed in the Skagerrak. The same phenomenon was not observed in the Kattegat. Only a few species and few cells were found in the Skagerrak waters at the ordinary phytoplankton stations. This was evident from the quite low fluorescence found at all stations. However, a quite diverse community was observed in the northern part of Skagerrak, at Å13, mostly containing dinoflagellates. No surface aggregations of cyanobacteria were observed during the expedition. Quite many filaments of Nodularia spumigena and Aphanizomenon sp. were however observed in the eastern part and northern part of the Baltic Sea as well as the north part of the Kalmar Sound.