observations allow us to produce not only a qualitative, but even a 

 quantitative description of the trophic relationships in marine 

 planktonic communities. Based on the available materials (Jergensen, 

 1955; Mullin, Brooks, 1967; Zaika, Pavlovskaya, 1970; Pavlova et al . , 

 1971; Petipa et al . , 1971, 1974, 1975; Zhukov, 1974; Sorokin, 1974f, g; 

 Sameoto, 1974; Barna, Weiss Dale, 1974; Swale, Belcher, 1974; and 

 others) it is possible to construct a system of primary trophic 

 connections of the community of the Sea of Japan and the equatorial 

 region of the Pacific Ocean (Shushkina et al . , 1974) and to estimate the 

 feeding selectivity coefficient I^j (Shushkina, Kislyakov, 1975; 

 Vinogradov et al . , 1976). 



The rate of consumption C^-j of food at the jth level (group) by 

 organisms of the ith level (group) as a function of its concentration 

 can be described by the following equation (Ivlev, 1955; Winberg, 

 Anisimov, 1969; Petipa et al., 1971): 



'"Pax ,, _ -?*i 



\ 



Cij = C'ij (1 - e-^-^iJ), (3.6) 



where c is a coefficient which is assumed to be close to 1.0, X ^^ is 

 the tropho-ecologic coefficient (Menshutkin, 1971). The value of the 

 maximum diet of the ith group consuming the jth group Ct^j is determined 

 on the basis of the maximum diet of species of the ith group, including 

 all types of food cf ^ and the fraction which the biomass of the jth 

 group represents in the total biomass of food, considering feeding 

 selectivity (Shushkina, Kislyakov, 1975; Vinogradov et al., 1976). The 

 quantity Ct' can be described (Winberg, Anisimov, 1969) on the basis 

 of the cost of metabolism R and the maximum possible increase, given 

 that metabolism P , based on equations (3.1) and (3.5): 



,max /ninax 



..max 

 K2 



Cr = (Pi + R)-Uniin = R(— ^ + D-Umin- (3.7) 



1-K2 



3.3 Estimate of Production of Populations, Trophic Levels, 

 Zooplankton and the Planktonic Community as a Whole 



Based on equations (3.1-3.7), we can estimate the intensity of 

 production--the mean daily P/B coefficients--for individual populations, 

 for trophic and systematic groups of planktonic animals, for all 

 zooplankton, and for the planktonic community as a whole. 



The estimate of mean daily P/B coefficients for various groups of 

 marine tropical plankton, performed by a physiologic method, is 

 presented in Table 14. The initial data for calculation, obtained in 

 the western Pacific (44th and 50th cruises of the VITYAZ') allow us to 

 determine the range of change of P/B coefficients with the most probable 

 values of K2 (0.3-0.4) within limits of dimensions of animals for which 

 the energy equivalents (W = bl*") and metabolic rate (R = aWM have been 



298 



