Summary
Both the species diversity and total cell numbers were low at all stations along the west coast at the time of sampling. The genus Tripos (formerly called Ceratium) was the most common at all stations. The potentially toxic species Dinophysis norvegica* was also found in relatively high cell numbers at both stations in the Kattegat. The integrated (0-10 m and 0-20 m) chlorophyll concentrations were low but within normal for the month. The only exception was at Å17 in the Skagerrak open sea, where the concentration was slightly above what is normal.
The species diversity was generally high in the Baltic Sea, but the total cell numbers were low. The typical spring bloom species, the dinoflagellate Peridiniella catenata was abundant at several stations, and the ciliate Mesodinium rubrum and the green algae Binuclearia lauterbornii were present at all stations although in low cell numbers. A few diatoms were present in low cell numbers, only Skeletonema marinoi and Thalassiosira cf. baltica in somewhat high cell counts at BY5 and BY38 respectively. The integrated (0-20 m) chlorophyll concentrations were above normal for this month at BY38 and BY32. At the other stations the concentrations were within one standard deviation.