Abstract: Surface sediments were collected from seven stations in the Bering Sea during the fourth Arctic Chinese National Arctic Research Expedition in summer 2010. Fourteen groups of meiofauna were detected in 10-cm sediment cores: Nematoda, Copepoda, Polycheata, Kinorhyncha, Amphipoda, Bivalvia, Cumacea, Ostracoda, Tanaidacea, Gastropoda, Isopoda, Ophiura, Tardigrada, and others. The average abundance and biomass was 2658.89 ± 2452.86 ind·10 cm^-2 and 1587.56 ± 1452.65 μg·dwt·10 cm^-2, respectively. Maximum abundance and biomass of 7135.12 ± 429.43 ind·10 cm^-2 and 4056.42 ± 721.33 μg·dwt·10 cm^-2, respectively, was observed in shallow waters of the Bering shelf. Minimum abundance and biomass of 56.04 ± 39.38 ind·10 cm^-2 and 87.91 ± 85.60 μg·dwt·10 cm^-2, respectively, was observed in deep waters of the western Bering Sea basin. Nematoda accounted for 94.81% of average abundance, followed by Copepoda (3.60%), and 93.44% of meiofauna were found in the upper 6 cm of surface sediments. The similarity index between meiofauna communities in shallow and deep waters was only 30.72%. Abundance in deep waters was an order of magnitude lower than abundance in shallow waters. Abundance and biomass were higher in shallow waters of the Bering shelf than in shallow waters of the China Sea and deep waters of the western Bering Sea basin. Pearson correlations analysis between meiofauna and abiotic parameters indicated that abundance and biomass were negatively correlated with depth, sediment nutrient levels, and several diameter parameters. Meiofauna biomass may be more sensitive to environmental changes than abundance.

Key words: Anctic, Bering Sea, meiofauna, abundance, biomass