At the moment, there are 307 distinguishable species of pelagic micro algae registered in the Barents Sea, not including multiple subspecies and varieties (Makarevich, Larionov, 1992; Matishov et al., 2000). Taxonomically, 7 of them belong to the golden algae, Cryophyte, 148 – diatoms, 123 – dynophytes, 5 – green algae, 4 – to Haptophyta division, 8 – to Prasinophyta division and 6 species – to Euglenophyta and Cryptophyta algae. 49 species (16%) are oceanic, 178 (58%) – neritic, 39 (12.7%) – panthalassal species, 17 (5.5%) can be clearly defined as a fresh water species, however, they are typical representatives of the Barents Sea pelagic algae flora, abundant in estuaries and even in the open sea. 14 species (4.6 %) do not represent typical planktonic species, but belong to the microphytobenthos; however, they are regularly registered in the pelagic coastal zone and thus can be included in the list. Other species can’t be given an ecological characteristic.
Presently, according to the phytogeographical affinities, 119 (38.8%) species of the Barents Sea phytoplankton can be characterized as Arctic, 67 (21.8%) – boreal, 91 species (29.6%) – cosmopolitan, and no defined geographical affinity has been found for the rest of the species (Matishov et al., 2000).
Studies with high taxonomical resolution should be repeated with some years apart. Changes in the environment, e.g. temperature, current pattern or increase in nutrients, most likely will influence on the species composition or alteration in the portion of phytogeographical affinities. Increase in the sea temperature would most likely result in new species appearing in the Barents Sea.
