All stations along the Swedish West coast had a domination of small cells. The coccolithophore Emiliania huxleyi dominated in cell numbers at more or less all stations. Different species of the order cryptomonadales were also common. In the Kattegat the larger cells were dominated by the diatom Pseudosolenia calcar-avis and the dinoflagellate Prorocentrum micans. In the Skagerrak the larger cells were mainly different naked dinoflagellates. The integrated chlorophyll concentrations were low but within normal for the month.
Filamentous cyanobacteria were low in general in cell numbers this month and at BCSIII-10 in the southeastern Baltic they were absent. Only at the stations BY5 and BY15, Aphanizomenon flosaquae was found in rather high amounts. Pico cyanobacteria were abundant and at BY2 the diatom Dactyliosolen fragilissimus dominated in addition to ciliates and small flagellates. The chlorophyll concentrations were high in the Bornholm Basin and at BY1 the integrated concentrations were above normal for this month. The chlorophyll concentrations were high east of Gotland as well, mainly caused by filamentous and colony forming cyanobacteria.