concentration (Table 5) in the biota of these regions varied 

 depending on where the samples were taken, as did its average 

 concentration; however, they never exceeded 3.0 |ig/kg dry wt. 

 In the plankton and neuston of the Bering and Chukchi Seas 

 seven 4- to 6-nucleated PAH's were detected (Table 6). The 

 total PAH concentration in the plankton of the Bering Seas 

 ranged from 40 to 480. but in the neuston from 26 to 

 1 14.8 |ig/kg on a dry weight basis. As shown in Table 6, the 

 major PAH's in the plankton of the Bering Sea were 4- to 

 5-nucleated compounds, ( wt %): Chr, 40; BaA, 24.6; BbF, 22; 

 BaP, 11.8; and BkF, 1.6. Also BPer, lndeno( 123cd)pyrene 

 [IP], and BeP were detected in the phytoneuston of the 

 northwestern part of the Bering Sea. 



The total PAH concentration in the neuston of the Bering 

 Sea, as a rule, was somewhat lower than in the plankton and 

 varied from 11 to 115 |ag/kg on dry wt. basis. The total 

 concentration of PAH's in the neuston from the northwestern 

 part of the Bering Sea exceeded its concentration in the plankton 

 by a factor of 15-20. However, the composition and ratio of 

 PAH's were nearly identical for both the neuston and 

 theplankton; BaA plus Chr, 41; BbF, 36; BkF, 38; and BaP, 

 18.2. In the biota of the Chukchi Sea, the composition and 



distribution of PAH's was somewhat different from those in 

 the Bering Sea. 



The total concentration of PAH's in the plankton varied 

 widely, viz., from 12 to 677. For the neuston, they ranged from 

 20 to 1 88 |ig/kg on a dry weight basis. The percent weight of 

 individual PAH's in the plankton samples was 41 for Chr, 26 

 for BbF, 2 1 .9 for BeP, and 1 . 1 for BaP. In some cases, trace 

 amounts of BPer and IP were detected in plankton, and in one 

 case BeP was detected. 



In the neuston, PAH's are represented mainly by 4- to 

 5-nucleated compounds with the distribution ( wt% ) being BbF 

 (37.6%), BaA plus Chr (29%), BaP (25.8%), and BkF (75%). 

 Thus, in the biota of the ecosystem of the Bering and Chukchi 

 Seas. 4- to 5-nucleated carcinogenic PAH's are most common, 

 with Chr, BaA, and BbF predominating (Fig. 5). 



PAH's in Bottom Sediment 



The concentration of PAH's in sediment of the Bering Sea 

 varied from to 1.7 |ig/kg on a dry wt. basis. The maximum 

 of 1 .7 ng/kg was detected northwest of St. Lawrence Island 

 (Station 32), which is considerably lower than for the Baltic 

 Sea(Kirsoeffl/., 1985). 



TABLE 6 



PAH concentration in the biota (ng/1) of the Bering ( 1 ) and Chukchi (2) Seas {47th cruise of the 

 RA' Akademik Korolew July-November 1988). 



Indices 



BaA/ 

 Chr 



BPer 



BkF 



BbF 



BaP 



BeP 



IP 



71.0 



49.0 



2.1 3.0 



!1.4 11.7 



8.5 8.3 



Fig. 5. Distribution ol PAH's (wt%l in the biota ol the Bering Strait (Station 83); plankton (a), neuston (b). 



306 



