Algae report number 9, 2022

Type: Report
Author: Marie Johansen, Maria Karlberg


The phytoplankton diversity was high at all stations along the Swedish west coast. Diatoms dominated in cell numbers and Pseudosolenia calcar-avis was common. In Skagerrak the potentially toxic dinoflagellate Dinophysis acuta* was common. The coccolithophore Emiliania huxleyi was found in high cell numbers at all stations. The integrated chlorophyll concentrations (0-10m and 0-20 m) were low, but within normal for this month at all stations except at Å17 where it was a bit elevated. Diversity and cell abundance of phytoplankton were generally low in the Baltic Sea, but with highest diversity at BY5. BY5 was the only station where all three species of the summer bloom forming cyanobacteria were still present. The potentially toxic dinoflagellate Prorocentrum cordatum* was common at BY5. Generally, there were plenty of small species and groups, such as Gymnodiniales, Pyramimonas spp., Heterocapsa rotundata, Cryptomonadales and ciliates. The dinoflagellate Dinophysis norvegica* was present at BY15. The integrated chlorophyll concentration in the interval closest to the surface (0-10 m) was below normal at BY15, while the concentrations in both of the interavals (0-10 m and 0-20 m) were above normal at BY2, BY4 and BY38. Otherwise the concentrations were within the normal range for this month.