Comparison of the Far Eastern Seas and the North Pacific Ocean in Terms of Species Diversity, Its Components, and other Integral Characteristics of Net Zooplankton in the Epipelagial Zone

Abstract

As a result of large-scale plankton surveys carried out by TINRO-Center using the Juday net with a 0.1 m² opening in 1984-2013, comparisons can be made on the Chukchi and Bering seas, the Sea of Okhotsk, the Sea of Japan and the adjacent Pacific Ocean in terms of species diversity H (binary digits/specimen), species richness S (number of species), species evenness by number of individuals J (unit share), total population density in abundance units N (thousand specimen/m³) and biomass M (g/m³), and average individual weight of animal W (mg/specimen). It seems that when going from south to north plankton N, M, and W increase, while its H, S, and J decrease. However, among all these variables in a large water area scale no statistically significant (at the 95% confidence level) correlations (either positive or negative) were found due to the small number of points and relatively large number of exceptions. The latitudinal trend is broken by the Sea of Japan in terms of N, the Sea of Okhotsk in terms of S and H, and the Chukchi Sea in terms of J and W. It is noteworthy that here in spatial distribution of the same characteristics of pelagic and bottom macrofauna latitudinal zonation was not observed at all. It's a strange inconsistency that requires further more detailed studies.