In the Skagerrak, the phytoplankton community was rather low in diversity. In Kattegat the species diversity was a bit higher. A fluorescence maxima was found at almost all stations and these maxima were dominated by different species of the dinoflagellate genus Ceratium In the Baltic proper, surface aggregations of cyanobacteria were noted in the northeastern part of the Baltic proper. In The southern parts of the Baltic proper small strains of surface aggregations were only observed between Bornholm and Hanö Bight.
Phytoplankton analyses have been made on board the R/V Aranda with main focus on the cyanobacteria dominating in the Baltic bloom. The method used here is not the best for other plankton groups, nevertheless all organisms observed are reported. To follow the surface accumulations of cyanobacteria in the Baltic Sea by satellite interpretations: http://www.smhi.se/en/Weather/Sweden-weather/the-algae-situation-1.11631