According to the classification of V. G. Bogorov (1967), the boreal 

 area of the North Atlantic must be considered a highly productive 

 region of the world ocean. During the spring and summer, the biomass of 

 zooplankton in many regions of the Labrador Basin and the Norwegian Sea 

 reaches 500 mg/m3, in many cases exceeding 1000 mg/m3 (Pavshtiks, 1966; 

 Timokhina, 1968; Vladimirskaya, 1972). The biomass of all seston may be 

 2-3 times greater. In the fall and winter season, the biomass is rela- 

 tively low, rarely exceeding 50 mg/m3. 



An attempt to calculate the production of main components of plankton 

 communities in various water masses of the Norwegian Sea was made by 

 A. F. Timokhina (1968). Based on the materials of multiannual seasonal 

 plankton surveys, the annual production of the most numerous representatives 

 of the zooplankton in the Atlantic and mixed waters of the Norwegian Sea 

 has been calculated, and is presented in Table 5. These quantities should 

 be considered as minimal, since they do not include the production of the 

 euphausiids or hyperiids, due to the insufficient degree of study of the 

 annual dynamics of the number of these groups; the production of medusae, 

 on the other hand, may be exaggerated, since the calculations were based 

 on wet weight. The maximum annual production of phytophagous zooplankton 

 in the Atlantic waters of the Norwegian Sea is 22 g/m^, in the mixed waters-- 

 73 g/m2 wet weight, corresponding to 1.64 and 5.51 g C, or 19 and 67 kcal 

 beneath each square meter. These values are more than an order of magnitude 

 lower than the values of primary production calculated for these regions: 

 70-200 g C/m2, i.e., 650-2000 kcal/m2 (Vinberg, 1960). Thus, in the Atlantic 

 waters of the Norwegian Sea, phytoplankton is to some extent underutilized 

 by the phytophagous zooplankton. 



Table 5. Production of mass planktonic species beneath entire area of 

 Norwegian Sea occupied by mixed and Atlantic waters, average for 1959-1963 

 (millions of tons) (Timokhina, 1968). 



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