Summary
The integrated (0-20 meters) chlorophyll a concentrations were normal for the season at all Skagerrak sites. Chlorophyll a concentrations were however above normal in Kattegat at N14 and on the second sampling occasion at Anholt E. The phytoplankton community in the Skagerrak and the Kattegat was dominated by several species of small cryptomonads, but also quite high numbers of the large dinoflagellates Ceratium were found. The species diversity was however low. The integrated (0-20 meters) chlorophyll a concentrations were high and above normal for the season in the southern and eastern parts of the Baltic Sea. Cryptomonads, and Pyramimonas spp. dominated in the Baltic Sea. The large diatom genus Coscinodiscus was found with relatively high numbers at several stations. High cell numbers of the genus Chrysochromulina was found between the islands Öland and Gotland. Some filaments of the cyanobacteria genus Aphanizomenon flos-aqua were observed at a couple of stations.