layer of bottom sediments was found to be rather uniform in 

 these seas, viz., 0.3 to 3.4 ng/g of dry mass of DDT, 0.3 to 

 9.2 ng/g of dry mass of PCB. 



In conclusion, it should be noted that these experiments 

 allow us to make a quantitative assessment of the influence of 

 chlorinated hydrocarbons on different elements of the Bering 

 Sea ecosystems. Therefore, on the basis of the data it was 

 calculated that the seawater in these regions contain, at present, 

 1.6 t of PCB's, 32.5 t of hexachlorocyclohexanes, 42 kg of 

 dot's, and 82 kg of chlordanes. Based on the preliminary 

 estimated data, bottom sediments have accumulated 1.8 t of 



DDT' s and 6 kg of HCH" s. Thus, the following conclusion can 

 be drawn. The PCB mass discharged into the ecosystem of the 

 Bering Sea is distributed in equal portions between the waters 

 and the upper layer (0-5 cm) of the bottom sediments. 

 Dichlorodiphenyltrichloroethanes and their metabolites are 

 mainly sorbed by the suspended solids and sedimented into 

 bottom sediments. As regards HCH isomers, their behavior is 

 conditioned by high volatility and dissolubility that results in 

 the accumulation of the main mass of the agent that is 

 discharged into an ecosystem from the waters of warmer 

 climates. 



TABLE 4 



The concentration of chlorinated hydrocarbons in neuston. 



Chlorinated Hydrocarbon Concentration 

 (ng/g dry weight) 



PCB 



3.5 

 3.7 

 2.5 

 2.3 

 2.5 

 2.6 

 2.8 

 2.3 

 3.1 

 4.1 

 3.7 

 3.5 

 3.8 

 3.5 

 1.9 

 3.5 

 6.5 

 7.1 

 5.1 

 7.1 

 3.3 

 3.5 

 2.8 

 3.6 

 5.5 

 4.3 

 6.0 

 3.3 

 3.4 

 3.9 

 3.5 

 3.3 

 4.3 

 4.6 

 5.9 

 4.8 

 4.9 

 4.8 



TABLE 5 



The concentration of chlorinated hydrocarbons in plankton. 



Chlorinated Hydrocarbon Concentration 

 (ng/g of dry weight) 



Station p.p'-DDE p.p'-DDD p.p-DDT PCB 



1 

 -I 



3 



4 



5 



6 



7 



9 



11 



13 



15 



18 



24 



27 



32 



35 



36 



41 



45 



47 



49 



50 



52 



53 



55 



57 



59 



61 



64 



67 



69 



72 



74 



82 



86 



92 



111 



1.2 

 1.1 

 0.5 

 1.1 

 0.9 

 0.9 

 0.6 

 0.6 

 0.8 

 1.2 

 1.2 

 1.3 

 1.4 

 1.8 

 0.8 

 1.9 

 1.5 

 1.2 

 1.5 

 0.8 

 1.0 

 1.0 

 2.0 

 1.3 

 I.I 

 I.I 

 2 2 

 0.5 

 0.5 

 1.0 

 0.4 

 1.3 

 1.2 

 1.3 

 0.7 

 0.9 

 1.5 



1.2 

 1.1 

 0.2 

 0.4 

 0.3 

 0.2 

 0.2 

 0.2 

 0.2 

 0.4 

 0.6 

 0.6 

 1.4 

 1.6 

 0.2 

 1.6 

 1.5 

 1.2 

 1.0 

 0.2 

 0.4 

 0.8 

 0.8 

 0.6 

 1.2 

 1.0 

 1.0 

 0.6 

 0.4 

 0.6 

 0.2 

 1.2 

 1.2 

 0.8 

 0.5 

 0.2 

 0.8 



283 



