measurements in the eastern part of the basin, at Station 67 

 (Table 2; Fig. 1). Comparatively small values of phytoplankton 

 production, about 400 mg C m - d ', were found at Stations 45, 

 49, and 50 (Table 2; Fig. 1). 



As was shown by the oceanographic and hydrochemical 

 research conducted by the American scientists during the 

 expedition, high productivity of the central and western regions 

 of the Chukchi Sea is explained by the penetration of waters 

 rich in nutrients, from the Anadyr current into these areas. In 

 addition, the western regions of the sea could be also influenced 

 by the flow of more saline and nutrient-rich waters moving to 

 the south along the coast of Siberia. Together with Anadyr 

 water brought from the Bering Sea, the above-mentioned 

 current can provide the rather high productivity of the Chukchi 

 Sea. The maximum concentration of chlorophyll, according to 

 the data obtained by the American specialists during our 

 expedition, reached 77 mg Chi m '. Shelf waters of the Chukchi 

 Sea along the coast of Alaska are considerably less enriched 

 with nutrients. Correspondingly, the concentration of 

 chlorophyll and the values of primary production are much 

 smaller in the eastern regio.is of the Chukchi Sea (Table 2; 

 Fig. 1 ). 



Because of the somewhat greater transparency of waters in 

 the Chukchi Sea, the depth of the euphotic zone there was 

 correspondingly deeper. However, similar to the Bering Sea, 

 it did not exceed 45-50 m (Tables 1.2). The maximum values 



of phytoplankton production were usually found at depths 

 between 5 and 15 m, which is probably related to optimal light 

 conditions. More seldom, the maximum of primary production 

 in the Chukchi Sea was discovered in the surface layers of 

 water (for example, on Stations 45 and 49) (Table 2; Fig. 1 ). 



Thus, the research of primary production in the Bering 

 Sea, conducted during the expedition on board the RA' 

 Akademik Korolev in 1988. made it possible to determine the 

 level of productivity of the central, southern, northwestern, and 

 western regions of the Bering Sea, including the Bering Strait 

 for the period of the end of biological summer to the beginning 

 of biological autumn. The results obtained indicate high 

 productivity of the Bering Sea ecosystem and great heterogeneity 

 of water masses from the point of view of biological parameters. 

 The data on the rates of photosynthesis in the Bering Sea 

 ecosystem, obtained in 1988, complement and extend the 

 results obtained in the course of expeditions in 1981 and in 

 1984. The results from the previous expeditions characterize 

 the status of plankton community of the Bering Sea during the 

 period of summer phase of the seasonal succession of plankton 

 community, while the results of the latest expedition cover the 

 period of biological autumn. 



The results, which were obtained during the joint 

 US-USSR ecological expedition in the Chukchi Sea, give an 

 idea of the level of productivity of the region during the period 

 of biological autumn. 



6.2 The Importance of Primary Production and 



STEPHAN I. ZEEMAN 



Department of Life Sciences, University of New England. Biddeford. Maine. USA 



Introduction 



The high-latitude seas are among the most productive 

 regions of the world (Koblentz-Mishke et al., 1970). This is 

 despite the low temperatures encountered here and the severely 

 reduced sunlight during the winter. The cold may even aid in 

 the transfer of energy to higher trophic levels since this reduces 

 metabolic requirements and losses through respiration ( Pomeroy 

 & Deibel. 1986). The Bering Sea has been the focus of recent 

 investigation by a team of scientists from the USSR and the 

 USA (Whitledge et al.. 1988). The data reported here is a 

 continuation of the effort begun in 1984 to characterize the 

 oceanography of the Bering Sea with respect to the importance 

 of phytoplankton primary production. High production rates 

 and biomass values have been reported throughout the Bering 

 Sea(Koikee/a/., 1982;Sambrottoe?a/., 1984, 1986; Whitledge 



etai. 1988). In the present study, the investigations extended 

 into the Chukchi Sea and areas of limited access. 



An important function of phytoplankton production is the 

 transfer of energy through food webs, which may ultimately 

 result in higher levels of production of commercially important 

 species. The Bering Sea is important in the production of 

 finfish and shellfish (Hood & Kelly. 1974). It is the largest 

 source of Pacific pollock, amounting to about 1.1 million 

 metric tons (Washburn & Weller, 1986). This rich resource 

 must be managed to sustain the populations, and this entails 

 assessing the available food resources. 



Global climate change has come to the forefront of public 

 attention with the international public, private, and scientific 

 sectors becoming concerned about the possible consequences. 

 Among the major unknowns in the global climate research is 

 the function of ocean systems. Potentially, the oceans could 



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