phyt 



CI, cr 



phyt 



Cl/C 



10"* 10^ 10^ 10' 10^ 10' 



phyt 

 I, cells/m^ 



Fig. 4. Comparison of mean values of parameters of productivity and 

 their relationships for oligotrophia (0), mesotrophic (M), and eutrophic 

 (E) surface waters of the World Ocean with cell count, N (cells/m-^) ; 

 B, raw biomass; Cp^y^, biomass expressed as carbon; P, primary 

 production; P', same, with correction for maximum possible systematic 

 error; CI, concentration of chlorophyll a; CI', same, with correction; 

 n, number of divisions per day. 



1.3 Environmental Factors Influencing Primary Production 



The combination of results obtained in experiments with individual 

 organisms does not explain fully the occurrence of processes in 

 communities, since complication of the biologic structure leads to the 

 appearance of additional properties. Therefore, the basic equations for 

 primary production as a function of environmental factors must be 

 derived from the results of observations at sea. 



Condi ti ons of i 1 1 umi nati on . Of the factors influencing primary 

 production in the ocean, the intensity of underwater illumination as a 

 reason for the variation in photosynthesis has been most thoroughly 

 studied. Light curves of photosynthesis are constructed for 

 quantitative description of this variation. Usually, samples from 

 different levels are exposed under different conditions of illumination 

 (at sea or in incubators) with parallel determination of the 

 concentration of chlorophyll. The data produced are used to construct 

 light curves of the assimilation number (AN). Another method is based 

 on exposure of aliquots of one sample to various light conditions. 



237 



