The phytoplankton genus Pseudochattonella spp.*, which is potentially mortal to fish when in high abundancies, was present with quite high cell numbers at all of the phytoplankton monitoring stations in the Kattegat and Skagerrak area. Fluorescence maxima at Anholt E, Å13 and Å15 were mainly caused by Pseudochattonella spp.* and the largest number, 120 000 cells per liter, was found at Å15. Signs of the coming diatom spring bloom were observed at N14 in the Kattegat and at Å17 in the Skagerrak by rather high cell numbers of Skeletonema marinoi. The integrated chlorophyll a concentrations were below normal for this month at N14, and normal in the rest of the Kattegat and Skagerrak area. Low cell numbers and few species were present in the Baltic Sea phytoplankton samples. Quite high cell numbers of the filamentous cyanobacterium Aphanizomenon flos-aquae was found at BY38. The integrated chlorophyll a concentrations were low, but mostly what is considered normal for this month.