Species diversity and cell numbers were low at Å17, but high at the other three stations. Å17 had mostly small species of dinoflagellates, such as Gymnodiniales, Heterocapsa rotundata and Karenia mikimotoi*. The other stations had both diatoms and dinoflagellates in various sizes, as well as some toxin producing species. Pseudosolenia calcaravis was the species with high cell numbers at Släggö, Anholt E and N14 Falkenberg. The integrated chlorophyll concentrations were normal at all stations for this month.
The species diversity and total cell numbers were overall low in the Baltic Proper. The filamentous cyanobacterium Aphanizomenon flosaquae was found in low amounts at all stations. Most commonly found at most stations were different cells of the Cryptomonadales group and various ciliates. At the southern stations so called naked dinoflagellates were common. The integrated chlorophyll concentrations were within normal for this month, the only exception being the southern stations where the concentrations were below normal.