Algae report number 6, 2018

Type: Report
Author: Marie Johansen


This cruise was not a full cruise with phytoplankton sampling at only three west coast stations and three stations in the Baltic Sea. The west coast stations Släggö and Anholt E displayed relatively high biodiversity. The coccolithophore Emiliania huxleyi was found at high cell numbers at both Släggö and Anholt E with the highest cell numbers of about one million cells per litre at Släggö. Satellite images from the same period indicated that there was high abundance of this species in many areas of the coast. Different diatoms were also common, but also the dinoflagellate Prorocentrum compressum. The sample from the off shore station Å17 had few cells. The integrated (0-10 m and 0-20 m) chlorophyll a concentrations were low but within normal for this month at all stations along the west coast, except at Släggö.

Among the Baltic Sea stations the coastal station REFM1V1 had quite high cell numbers of Skeletonema marinoi. Quite a few filaments of the cyanobacteria genus Aphanizomenon together with the diatom Dactyliosolen fragilissimus was found at the southern station BY2. The integrated (0-10 m and 0-20 m) chlorophyll a concentrations were within normal for most stations in the Baltic Sea. The exceptions being BY2 with higher concentrations than normal, BY32 where lower concentrations than what is normal was found and REFM1V1 with lower than normal concentrations of chlorophyll a concentrations in the upper part (0-10m) of the water column.