This report presents the results from two September cruises. A small diatom bloom was proceeding at the Skagerrak coast and in the Kattegat area during the second cruise. In open Skagerrak, the plankton flora was scarce with a few small species in low cell numbers. The integrated chlorophyll a concentrations were within average for this month. The phytoplankton situation was very calm in the Baltic. The filamentous cyanobacterium Aphanizomenon flosaquae was common at all stations except at BY2. Small flagellated species dominated the samples. The integrated chlorophyll a concentrations were low in the Eastern Baltic Proper, and within average for this month at all other stations.