In the Skagerrak and the Kattegat the autumn bloom, dominated by diatoms, was developing. Large amounts of Chaetoceros and Pseudo-nitzschia species were present. Dinoflagellates were also common. In the Baltic cyanobacteria had almost disappeared and large diatoms, some dinoflagellates and small flagellates dominated. In the Arkona and Bornholm basins diatoms normally belonging to more saline water was present. East of Gotland there was a Prorocentrum minimum bloom with peaks also in the deep water. One such peak was found at 130 m depth.