Scale-covered and loricate flagellates (Chrysophyceae and Synurophyceae) from Baltic Sea ice

The protistan communities living in the brine channels of Baltic Sea ice have been studied with particular emphasis on scale-covered flagellates (Chrysophyceae and Synurophyceae). Water column, brine, and ice core samples were obtained during a cruise along the Finnish coast in March 1994. The material was examined by means of light microscopy of live cells and transmission electron microscopy of whole mounts. The most conspicuous and numerous scale-covered chrysophytes were complete cells of several species of Paraphysomonas. The material additionally comprised loricate chrysophyte taxa and detached scales of Synurophycean genera. The finding of loose scales of several freshwater taxa indicates that a significant amount of material from land is incorporated into Baltic Sea ice. This paper comments on the ecology and geographical distribution of species encountered as complete cells in ice samples. Measured environmental variables comprise temperature, pH and salinity.