Algae report number 4, 2024

Type: Report
Author: Marie Johansen, Maria Karlberg


Due to bad weather, all of the Skagerrak stations except Släggö were not sampled. The spring bloom had passed and the cell concentrations and biodiversity were overall low. Some chains of Skeletonema marinoi and Guinardia delicatula was still present as a remembrance of the spring bloom. Except for the diatoms, small flagellates of different sorts were most common. The integrated chlorophyll concentrations were above normal at both N14 Falkenberg and Släggö but normal at Släggö. Due to the unsafe situation in the Eastern Baltic Proper, BCSIII-10. BY10 and BY15 were not sampled. In the Baltic Sea, the spring bloom was ongoing! The northern stations, BY31 and BY29, had a clear dominance of the typical spring bloom diatom species; Chaetoceros wighamii, Pauliella taeniata and S. marinoi. In contrast, the southern stations, BY2 and BY5, had S. marinoi but also several other groups in a more varied phytoplankton community. The integrated chlorophyll concentrations (0-10 m and 0-20 m) were normal for the month at all stations, except at BY31 and BY29 where they were higher.