Algae report number 10, 2023

Type: Report
Author: Marie Johansen


Only two stations could be sampled along the Swedish west coast due to the hard wind and high waves. Both stations, Släggö in Skagerrak and Anholt in Kattegat, had quite high biodiversity with a dominance of diatoms. Among the diatoms the potentially toxic genus Pseudo-nitzschia* was common. The coccolithophore Emiliania huxleyi was common in the Kattegat. The intergrated chlorophyll concentrations were within normal with only one exception, at Anholt E, where the integrated chlorophyll concentrations for 0-10 m were above normal for this month. The diversity and cell numbers of phytoplankton were low at most stations in the Baltic Proper. Of the three summer bloom forming filamentous cyanobacteria, only a few filaments of Aphanizomenon flosaquae was found at the south easterly stations. At the same stations several species normally found along the west coast was also found. At the other Baltic stations, a dominance of small species was noted. The integrated chlorophyll concentrations (0–10 and 0–20 m) were generally within the normal range for this month at most stations in the Baltic Proper The only exception being BCS III-10 where they both were below normal.