Summary
The phytoplankton diversity and total cell counts were low in the Kattegat and Skagerrak areas, except at Släggö where the diversity was a bit higher. The toxic species Dinophysis acuta* was found in relatively high cell numbers at Släggö. The diatom Proboscia alata was common at all stations along the Swedish west coast. At Anholt E quite a few of the coccolithophore Emiliania huxleyi on both sampling occasions. The integrated chlorophyll concentrations (0-10m and 0-20 m) were low at all stations but within normal for the month. Diversity and cell abundance of phytoplankton were high in the south-western parts of the Baltic, at BY2 and BY5, and at the coastal station REFM1V1. At the other stations both numbers and diversity were lower. The cyanobacterium Aphanizomenon flosaquae was present at all stations, sometimes in high cell numbers (BY2, BY5 and BY38), while Dolichospermum sp. had high cell numbers at REFM1V1, BY2 and BY15. Nodularia spumigena* was only present with a few filaments at most stations. At BY2 and BY5, the diatom Dactyliosolen fragilissimus was present in high cell numbers. At BY2 there were also several Dinophysis acuminata* and cells of the order Prymnesiales*. The integrated (0-10 m) chlorophyll concentration was below normal at BY15, otherwise concentrations were within the normal range for this month.