Summary
An extensive spring bloom was observed at all phytoplankton stations in the Kattegat and Skagerrak areas. The diatom Skeletonema marinoi dominated the samples. The general species composition was more or less the same in the whole area, many diatom species in high cell numbers and a few dinoflagellates in low cell numbers. Among other groups, the flagellate Eutreptiella braarudii was common. The integrated chlorophyll a concentrations were above normal in the Kattegat and the Skagerrak. Winter calm prevailed in the Baltic except at ref.M1V1 in the sound of Kalmar where diatoms bloomed, dominated by Skeletonema marinoi. The chlorophyll a concentrations were low. Missing permits caused that some of the stations were moved to Swedish waters this expedition and a few had to be excluded. At BY29 in the northern Baltic Proper the hydrographic winch broke down, why only surface samples were taken at the remaining stations. Integrated chlorophyll a is therefore missing at some stations. http://www.smhi.se/oceanografi/oce_info_data/reports/cruise/exp_0912eng.pdf