Algae report number 5, 2021

Type: Report
Author: Ann-Turi Skjevik, Marie Johansen


All stations along the west coast had a domination of diatoms and far most common was Skeletonema marinoi. Among the dinoflagellates the genus Tripos was most common. Chlorophyll concentrations at all stations were normal for this month. Worth mentioning is that Anholt E was visited twice. On both occasions a fluorescens peak was found at about 20 meters. On the first occasion it contributed to the integrated chlorophyll concentration (0-20 m) being a bit high. On the second occasion the chlorophyll concentrations were lower and consequently the integrated values were normal for this month. A bloom of the potentially toxic group Prymnesiales was observed in the southern and southeastern Baltic with the highest cell numbers quantified at BY4. The filamentous cyanobacterium Aphanizomenon flosaquae was found in rather high amounts at the stations BCSIII-10, BY15, BY29 and BY38. A chlorophyll fluorescence maximum at BY32 was mainly caused by the Prasinophyceae Pterosperma sp. The integrated chlorophyll concentrations were within normal at all stations except BY2 where they were below normal for this month.