Summary
The integrated (0-20 meters) chlorophyll a concentrations were within normal for the season at most of the Skagerrak and Kattegat sampling sites. One interesting exception was Släggö with lower concentrations than normal but with a very high cell density in the phytoplankton sample that was analysed. The phytoplankton community was variable in the Skagerrak, with a high diversity and high cell density at Släggö while the opposite situation was found at Å17. Large and toxic/non-toxic dinoflagellates dominated at Släggö but mostly small naked dinoflagellates (10-20 μm) together with cryptomonads dominated at Å17. The stations in Kattegatt had a very low cell density and species diversity. The community was dominated by cryptomonadales and small flagellates. The genus Chrysochromulina was common and some large and toxic species from the genus Dinophysis were present. The integrated (0-20 meters) chlorophyll a concentrations from the Baltic Sea were within normal for the season at all stations. Cryptomonads together with the genus Pyramimonas were dominating the samples at all stations. Both colony forming and filamentous cyanobacteria had diminished since the last expedition, but the fish toxic genus Chrysochromulina was still common if not dominating.