64 to 85 ng/1 (the East Polygon and the Chirikov basin) and 

 185 ng/1 in the Bering Strait. These high levels were found in 

 photic layers of the water column (0.5 to 25 m). At the same 

 time, BaP concentrations up to 40 ng/1 were recorded in deep 

 water 1,000 to 3,000 m, the East Polygon, Station 3; and 

 20 ng/1 at the South Polygon, Stations 109 and 1 10. 



The BaP vertical distribution was also relatively 

 homogeneous and, unlike the 1984 samples, did not tend to 

 accumulate in the surface samples. However, 14 maxima out 

 of the 42 that were measured (18% of the total number) 

 corresponded to the 0.5 and to the 1 1 to 25 m horizons. 



The most homogeneous vertical distribution of low BaP 

 levels was found in samples from the southern area of the Gulf 

 of Anadyr (Station 6 — 0.6 to 1 .6 ng/1 ), in the central part of the 

 Gulf of Anadyr (Stations 22, 24, and 27—0.8 to 4.0 ngA) and 

 in the 10 to 500 m water layer at the East Polygon where it was 

 1 to 6 ng/1. 



The South Polygon contained BaP concentrations in the 

 water between 1 to 21 ng/1, with those samples in the 0.5 m 

 surface layer at 4.15 ng/1. The average for this entire station 

 was 4.15 ± 0.37 ng/1. The highest BaP concentrations were 

 found in deep water ( 1 ,000 to 3,000 m) in the western part of 

 this polygon at Stations 109. 110, and 111. The southwest 

 Station 1 1 1 showed relatively high concentrations at 0.5 and 

 45 m depths; this area also produced higher levels in 1984. 



At Station 1 13, which was east of the South Polygon, the 

 BaP concentrations at the depth range of 25 to 2,000 m were 

 characterized by considerable homogeneity, 1 .2 to 3 ng/1, and 

 only in surface water (0 to 1 m ) were the levels higher, ranging 

 from 8 to 13 ng/1. 



At the East Polygon, the BaP concentrations at the depth 

 of 1,000 m was also relatively homogenous and low. 1 to 

 3 ng/1, which was the same in 1984. However, some individual 

 horizons showed BaP concentrations that were among the 

 highest concentrations found in 1988 (i.e., 25 to67 ng/1). Also, 

 some of the highest values recorded in 1988 were at the 0.5 m 

 layer (up to 59 ng/1) and at the depths of 100 to 1 .000 m (see 

 Fig. 1 ). Note that the highest BaP concentration recorded in 

 1984 in the southeast part of this sampling area was 46.6 ng/1. 

 The average BaP value in the East Polygon water was among 

 some of the lowest compared with the other areas tested this 

 year (i.e., 3.34 ±0.54 ng/1). 



The Gulf of Anadyr was investigated for the first time. It 

 showed a pronounced BaP homogeneity and was uniformly 

 characterized by low levels of 0.5 to 5.8 ng/1 (93% of the 

 determinations). At anumber of stations, the BaP concentration 

 throughout the whole water depth varied over even a smaller 

 range (i.e., 1 to 3 ng/1). The exceptions were the 3 stations in 

 the southern part of the gulf where the concentrations in the 

 surface horizons ( 10 to 25 m) ranged from 1 6.5 to 23.9 ng/1 ( see 

 Fig. 1 ). The average BaP value for the entire area of the Gulf 

 of Anadyr was 2.22 ± 0.22 ng/1, the lowest among all the 

 investigated northern regions. 



On the shelf near St. Lawrence Island, in the water of the 

 larger part of the investigated horizons of the North Polygon, 

 low BaP concentrations of 1 to 6 ng/1 dominated, with the 

 average value being 3.68 ± 0.65 ng/t. The most homogeneous 

 BaP distribution with depth was observed in the southern part 



of this polygon. Higher concentrations, up to 25 ng/1 in the 1 

 to 25 m horizon and 34 to 52 ng/1 in the 0.5 meter surt'ace layer 

 were confined to the northern part of this region nearest to 

 St. Lawrence Island (see Fig. 1). However, these recorded 

 maxima were lower than in 1984. 



At higher latitudes the BaP distribution was characterized 

 by generally higher concentrations. 



The water of the shallow Chirikov basin, the area between 

 St. Lawrence Island and the Bering Strait, contained an average 

 BaP level of 4,63 ± 0.54 ng/1. with the maximum values for 

 individual samples being 2 to 4 ng/1. However, most stations 

 ( see Fig. 1 ) at the to 25 m depths showed increased BaP levels 

 up to 68 to 85 ng/1. The highest BaP concentrations, both for 

 this area and other areas in the north, were recorded at the 

 45 m depth in the western part of the Bering Strait that had a 

 value of 185 ng/1. 



Of considerable interest are the samples that were collected 

 for the first time from the southern part of the Chukchi Sea 

 ( Stations 44 to 8 1 ). In the southern region of this investigated 

 area, the BaP concentration over the water depth profile, 

 including the surface layer, was within 0.8 to 3 ng/1; however, 

 in the northern part of this area, BaP concentrations up to 

 15-56 ng/1 were measured, with maxima near the Alaska 

 coastline (Station 64). The distribution of the high BaP water 

 plume covered quite a pronounced area interacting in the north 

 with the floating sea ice boundary (see Frontispiece station 

 map). The vertical BaP distribution in this relatively shallow 

 area (50-60 m) did not have any pronounced stable maxima 

 since the higher BaP levels were found throughout the whole 

 water depth from the surface to near-bottom horizons. 



Special note should be taken of the BaP concentrations in 

 the samples of sea ice and the water collected from the surface 

 microlayer (0 to 200 |a) that were taken at 68°N latitude. 

 (Station 45). These values were 13 to 18 ng/1 and 20 ng/1, 

 respectively. There was significant BaP concentration in the 

 ice. With considerable ice areas occurring in the Chukchi Sea 

 even in summertime, this would indicate that there is a potential 

 danger from PAH accumulation in this substrate and the levels 

 are reaching those that might pose a real threat to this vulnerable 

 northern sea ecosystem. 



The results of this investigation show a wide distribution 

 of BaP in the water and even ice cover of this subpolar region. 

 The most frequently occurring concentrations were low levels, 

 near the natural levels of 5 ng/1, with the BaP concentrations 

 slightly higher at the northern latitudes (65°N latitude and 

 higher). It was at these latitudes that most of the higher BaP 

 concentrations (60-80 ng/1) were found. These areas include 

 the East Polygon (deep water horizons) and the North Polygon 

 (northern stations), as well as several locations in the Chirikov 

 basin and the northern part of the investigated regions of the 

 Chukchi Sea. 



Not only is BaP present in the waters of the Bering Sea and 

 the Chukchi Sea, it is also found in the bottom sediments of 

 these regions. In 1988, BaP was recorded in sediment at most 

 of the 43 investigated stations. The exceptions were only 6 of 

 the 43 locations that were in the southern part of the Gulf of 

 Anadyr ( Station 6 and 7 ), to the north from St. Lawrence Island 

 (Station 102), and along the Alaska coast (Stations 66, 



310 



