In the open Skagerrak the plankton flora was poor with few diatoms and dinoflagellates. Close to the coast the abundance was higher with more diatoms and a small bloom of Skeletonema costatum. In the Kattegat diatoms were absent and dinoflagellates were few. Chrysochromulina spp. were the most abundant. In the Baltic Aphanizomenon sp. was common in Arkona basin and east of Gotland. Nodularia spumigena was almost absent. In Arkona Dactyliosolen fragilissimus and Ceratium tripos reached high abundance, which may indicate inflow of saline water. Prorocentrum minimum was also common.