Mean annual characteristics of zooplankton in the Sea of Okhotsk, Bering Sea and Northwestern Pacific (Annual and seasonal biomass values and predominance)

Abstract

Averaged data on fractions, groups and species of zooplankton in the epipelagic of the Sea of Okhotsk, Bering Sea and Northwestern Pacific are based on the results of plankton studies in 1984-2006 carried out during TINRO-Center expeditions. The material is presented at the following levels: (1) general mean annual quantitative characteristics for the Sea of Okhotsk, Bering Sea, and Northwestern Pacific; (2) the same characteristics for more fractional subdivisions of regions, such as the biotopes of outer and inner shelves and deepwater areas; (3) specification of data for certain time spans (1984-1990; 1991-1996; 1997-1998; 1999- 2006); (4) seasonal dynamics of the basic components; and (5) the predominance of species in each biotope. The obtained quantitative data allowed determining a series of peculiarities in the main constituents of plankton communities on both seasonal and long-term scales. These averaged parameters can serve as some criterion for the evaluation of probable changes that could take place in the plankton of the studied areas.