Abstract:

Based on 48 net samples and 24 water samples from Chukchi Sea(66°0.3N-75°18.6N,153°36.5E-174°59.5W) and Bering Sea (55°59.8N -66°0.3N, 173°21.1E-175°53.9W) collected during FCNARE(1999) cruise of Xuelong Research Vessel of SOA, China, 121 phytoplankton species (including varieties and forms) in 43 genera of 3 phyla have been identified. Among them, 103 species in 33 gerera were from Chukchi Sea , 71 species in 25 genera were from Bering Sea, and 49 species were from both two seas. These species can be divided into 4 ecological groups:(1) Arctic group; (2) Arto-subarctic group; (3) Boreal-temprate group and (4) Eurythemal group. The dominant species were respectively Nitzschia grunowii, Thalassiosira nordenskioldi and Chaetoceros socialis in Chukchi Sea, and Denticula seminae, Nitzschia delicatissima, Nitzschia seriata and Thalassiothrix longissima in Bering Sea. The average abundance (8.32×10 7cells/m 3) of phytoplankton from Chukchi Sea was higher than that (1.58×10 6cells/m 3) in Bering Sea. The distribution characteristics of phytoplankton in surveyed areas and their relationship with the environmental factors (including biological factors) are discussed .