Summary
All stations along the Swedish west coast had a dominance of diatoms. A bit surprising was also to find several cells of the bioluminescent dinoflagellate Noctiluca scintillans, at all stations. Except for this, small flagellates of various taxa were the most common, and in Skagerrak Emiliania huxleyi was common. The integrated chlorophyll concentrations were above normal at the Skagerrak stations but normal for this month in the Kattegat. The phytoplankton situation was extraordinary similar at the various sampling stations in the Baltic Sea. The filamentous cyanobacterium Aphanizomenon flosaquae was found in enhanced amounts at all stations. The potentially toxic cyanobacterium Nodularia spumigena, also filamentous, was found in low amounts at stations BCS III-10, BY29 and BY39. The potentially toxic dinoflagellate Dinophysis acuminata* was present at all stations and was found with the highest cell numbers at BY31. Colony forming cyanobacteria were generally numerous. Chlorophyll fluorescence maxima were mainly caused by a prymnesiales* species. The integrated chlorophyll concentrations from 0–10 meters were above normal at BY2 and the Hanö Bight. The 0–20 meters concentration was below normal at BCSIII-10, otherwise within normal for this month at all other stations.