6-10°C, and salinities >33% in surface water. In the Chukchi 

 Sea, the ecograms differed between Stations (Fig. 7). The 

 largest mean number of PCBB (8.8x1 0' cells/ml ) again found 

 in the waters with salinities of 3 1 .35-33.009; and temperatures 

 >6°C (Fig. 7). 



The resemblance of ecograms between the Chukchi and 

 Bering Seas (Fig. 6) indicates the variety of functional groups 

 that exist in these seas and that these groups are widely 

 distributed and comprise an integral part of the ecosystem. 

 These ecograms illustrate again the variability and patchiness 

 of these groups in these seas. 



In summary, from the results on the number and distribution 

 of saprophytic, hexadecane-oxidizing. BaP- and PCB- 

 transforming bacteria in the Bering and Chukchi Seas, and 

 comparison with investigations conducted in 1981 and 1984, 

 we found: 



/. In the summer of 1988, SB were ubiquitous, albeit 

 highly variable, in the Bering and Chukchi Seas. In the Bering 

 Sea, these bacteria occurred most frequently at hundreds of 

 cells/ml, whereas in the Chukchi Sea, they exceeded 

 10' cells/ml. Based on boreal concentrations of SB. the Bering 

 Sea can be characterized as oligomesotrophic and the Chukchi 

 Sea as mesotrophic. 



2. Hexadecane bacteria were also highly variable in the 

 Bering and Chukchi Seas. In the Bering Sea, maximum 

 numbers changed little since 1984 and were most abundant in 



the Bering Sea (South Polygon) where significant concentrations 

 of anthropogenic hydrocarbons occurred. 



3. Benzo(a)pyrene-transforming bacteria were also variable 

 in the Bering and Chukchi Seas. These bacteria were widely 

 dispersed in the Chukchi Sea, generally at lOcells/ml. Although 

 the distribution of BaP-transforming bacteria was also patchy 

 in the Bering Sea (the Chirikov basin, the Bering Strait, South 

 and East Polygons), BaPB were most abundant at 1 00 cells/ml. 



4. PCB-transforming bacteria covaried with the distribution 

 of BaP-transfomiing bacteria. 



5. Relative to 1981 and 1984, numbers in each functional 

 group and their distribution increased significantly in summer 

 1988. suggesting that the Bering Sea ecosystem is experiencing 

 anthropogenic inputs. 



6. From characterizing the number and distribution of 

 each functional bacterial group ( in particular. PCB-transforming 

 bacteria) in the Bering and Chukchi Seas, we conclude that 

 there exists an anthropogenous effect on the ecosystems. The 

 degrees of entrophication varies with each region. In the 

 central Bering Sea, as well as in the Gulf of Anadyr, 

 anthropogenic impact is minimal. However, in the northern 

 Bering Sea and in the southern Chukchi Sea, anthropogenic 

 influences are evident. Because of the remoteness of the area 

 from big industrialized centers, the presence and distribution of 

 PCB- and BaP-transforming bacteria indicates the global 

 propagation of organic pollutants via atmospheric processes. 



4.2.2 Taxonomic Composition of Heterotrophic 

 Bacteria 



ALLA V. TSYBAN\ GENNADIY V. PANOV\ SVETLANA P. BARINOVA, VLADIMIR I. IVANITSA', and 

 GALINA V. KHUDCHENCO= 



'Institute of Global Climate and Ecology. State Committee for Hydrometeorology and Academy of Sciences. Moscow, USSR 

 ^Odessa State University. Odessa, USSR 



Introduction 



Methods and Materials 



The study of the morphologic characteristics and taxonomic 

 composition of microorganisms of the Bering Sea was started 

 in 1 98 1 and 1 984, and continued in 1 988 during the Third Joint 

 US-USSR Bering & Chukchi Seas Expedition. In 1988, 

 investigations included microbial structure (microbial 

 population including taxonomic diversity ) of the Chukchi Sea. 

 It is noteworthy that these microbiological investigations were 

 conducted over extensive areas of the Bering and Chukchi Seas 

 and that they included the taxonomic determination of 

 heterotrophic bacteria that were isolated from different sites of 

 the marine environment. 



The taxonomic investigation included 829 strains of 

 bacteria isolated from different sites of the marine environment 

 (the water column, bottom sediments, and biota): 432 strains 

 isolated from the Bering Sea in summer 1981; 320 strains 

 isolated from the Bering Sea in summer 1984; and 77 strains 

 isolated from the Chukchi Sea in 1988. In addition, the results 

 are compared to bacterial cultures isolated from the Baltic Sea 

 impact region of the World Ocean. 



Bacteria from the marine environment and their culture 

 were isolated using fish broth and fish peptone agar prepared 

 with fresh seawater(Tsyban. 1980). The inocula were incubated 

 at 28°C. 



87 



