SEASONAL-VARIATIONS OF MESOPLANKTON BIOMASS IN THE UPPER LAYER OF THEBERING-SEA - UNDERSTANDING BIOMASS OSCILLATIONS IN THE OCEAN

Data on the mesoplankton biomass in the upper layer (down to 100 m) of the western part of the Bering Sea and the adjacent regions of the no rth-west Pacific were fitted to a periodic regression. The biomass val ues (wet weight) change from 74 mg m(-3) in winter to 770 mg m(-3) in summer, the annual average value being 240 mg m(-3). These changes clo sely agree with the seasonal biomass oscillations in the north-east Pa cific at Weather Station ''P'' (50 degrees N, 145 degrees W), which we re determined on the basis of long-term observations. These results we re used to analyse data derived mainly from published literature to pr oduce equations that describe the pattern of seasonal zooplankton biom ass oscillations in the World Ocean. The result confirms the intuitive ideas of planktonologists: phases of these oscillations are approxima tely opposite in the two hemispheres, and the phase shift from the Pol es to the Equator reaches about two months in the Northern Hemisphere and at least three months in the Southern Hemisphere. (C) 1995 Interna tional Council for the Exploration of the Sea