decreased sharply depending on the depth. It is considered 

 (Tanabe. 1985) that the circulation of water masses and 

 biogenous sedimentation (one of the most important processes 

 for contaminant removal from the ocean surface layers) 

 contribute to the passing of chlorinated hydrocarbons through 

 the deep-water layers of the aquatic system. 



Investigation of the ice sample in the Chukchi Sea show 

 that the concentration of HCH isomers reaches 3.4 ng/1, the 

 DDT amount reaches 0.016 ng/1 and the PCB amount reaches 

 the 0.9 ng/1 level. 



The availability of chlorinated hydrocarbons was identified 

 in practically all samples of suspended matter (Table 3 ). Thus, 

 using these data, it was found that the DDT accumulation 

 coefficients ( DDT concentration ' n the suspended matter/DDT 

 concentration in the water) for the suspensions were greater 

 than 100 and even reached as high as 1,000 in some of the 

 surface collections. 



The analyses of the suspended matter also showed that the 

 HCH isomers are mainly in a dissolved state while the PCB 

 concentration is evenly dispersed between two phases. It was 

 also noted that the dissolved PCB forms usually included 

 components with a low number of chlorine substituents, and 

 the adsorbed forms mainly consisted of components with a 

 larger number of chlorine substitutions. When studying the 

 deepwater samples, however, and the relationship between the 

 concentration of the adsorbed forms, the reverse correlation 

 was found out — that is, the lower the level of chlorinated 

 hydrocarbons dissolved in the water, the more was their affinity 

 with the suspended phase. Therefore, the agents with low 

 water solubility — for example, DDT's and highly chlorinated 

 PCB ' s are sorbed by the suspended matter and easily transferred 

 from the surface layers to the deep ones. At the same time, this 

 process for low-chlorinated PCB's (the more soluble forms) 

 ; nd lindane is less active. 



Based on the suspended sediment data it was also found 

 that the fraction of sorbed chloroorganic compounds increases 

 with the transition to the higher latitudes where the volume of 

 the suspended agents was higher. 



Chlorinated hydrocarbons were also identified in all 

 samples of plankton and neuston (Tables 4,5). Note that the 

 accumulation coefficients in zooplankton were 10,000 to 

 100,000, and the absolute concentration was 45 to 90 ng/g of 

 fat. The PCB accumulation coefficients in samples of plankton 

 and neuston also ranged from 1,000 to 100,000. In contrast 

 with the suspended solids, there was a more even concentration 

 of all polychlorobiphenyl components in samples of plankton 

 and neuston, which can evidently be explained by their 

 overriding uniform lipophilic properties. Some residue data 

 for chlordanes was also collected for the plankton; however, 

 because of some methods problems, we can only qualitatively 

 state that cis-chlordane, trans-chlordane, and trans-nonachlor 

 appear to contribute a great amount to the total of CMC's 

 measured in the plankton. 



The bioaccumulation of chlorinated hydrocarbons is even 

 more obvious in benthic organisms (Table 6). The concentration 

 of the DDT group in samples of benthic organisms varies from 

 3 to 49 ng/g of dry weight; the concentration of 

 polychlorobiphenyls ranges from 2 to 102 ng/g of dry weight, 

 with the PCB fractions having a balanced concentration both of 

 low- and high-chlorinated biphenyls, and the DDT fraction had 

 an increased concentration of 2,4'- (not reported in the tables, 

 but indeed observed) and 4,4'-DDE components, which is 

 evidently connected with the consumption of the partially 

 dehydrochlorinated DDT mixture by benthic organisms. 



This investigation did not permit a determination of the 

 dependence of the chlorinated hydrocarbon concentration in 

 benthic organisms on the concentration of this material in the 

 respective bottom sediments since contamination of the upper 



TABLE 3 



The concentration of chlorinated hydrocarbons in suspended matter. 



Chlorinated Hydrocarbon Concentration 

 (ng/g dry wt) 



Station a-HCH 6-HCH p.p-DDE p,p'-DDD p.p-DDT PCB 



282 



