Island lo Bering Strait (11 trawl samples and 35 dredger 

 samples); and in the southwest Chukchi Sea ( 1 8 trawl samples 

 and 43 dredger samples; Figs. 1,2). In addition, five trawl 



180 



175 



170 



65 



63 



62 



61 



Fig. K Distribution of quantitative (A) and qualitative (^) samples at 

 stations in 1988 in the Gulf of Anadyr and neighbonng waters in the 

 Bering Sea. 



170 



Chukchi Sea 



Bering Sea 



Fig. 2. Distribution of quantitative (▲) and qualitative (^) samples of 

 benthos at stations in 1988 in the southeastern part of the Chukchi Sea 

 and in the northern part of the Bering Sea. 



samples and eight dredger samples were collected in sampling 

 grids further south in the Bering Sea, designated as East and 

 South Polygons. The East Polygon was in the central part of the 

 Bering Sea covering both its continental shelf and slope, and 

 the South Polygon was in the southern part of the Bering Sea, 

 near the Aleutian Islands. 



Samples were collected with the following equipment: 

 Sigsby trawl (small size version: 0.9 m entrapment width, 

 0.5- mm mesh, 20-min trawl at 3 knots); dredger Ocean 

 (entrapment area 0.25 m-), and van Veen bottom sampler 

 (entrapment area 0. 1 m'). Dredging and trawling were carried 

 out from starboard using a winch on the bow of a ship. 

 Trawling was carried out for 20-min time periods while the 

 ship was adrift. Most of the dredged samples were collected 

 with a van Veen sampler. Usually two dredger samples at one 

 station were averaged and treated as one sample. Meiobenthos 

 samples were taken from the dredger samples. Seabed fauna 

 was washed off on a washer using a set of 1 0. 5 , and 1 mm mesh 

 sieves. After treatment, the extracted organisms were fixed in 

 4% formalin or 75% ethanol. The collected material was 

 classified and treated in the ship lab. Preliminary identification 

 of organisms was carried out to lowest taxon level possible. 

 Final analysis of benthic material is still under way in the 

 Institute of Zoology (USSR Academy of Sciences). 



Results 



The following section presents a brief review of the 

 benthos of each of the investigated regions of the Bering and 

 Chukchi Seas. 



The Gulf of Anadyr and Neighboring Waters 



The research work in the studied regions of the Gulf of 

 Anadyr was carried out in the central part of the gulf and on the 

 shelf at the gulf outlet. Due to the limited quantitative material 

 obtained, only 5 biocenoses (Fig. 3) with 28 dominant benthic 

 forms were determined (Table 1 ). Average biomass of benthos 

 in the region equals 461 g m-. The most widespread benthic 

 community is the biocenosis of ark shells Macoma cakarea 

 that inhabit the entire central part of the Gulf of Anadyr at 

 depths of 47-140 m. This biocenosis is subdominated by ark 

 shells (Leionucula inflata, Cyclicardia crebricostata. and 

 Yoldia). polychaetes (Amphictene moorei, Nicomache 

 himbricalis. and Nephtys ciliata), ophiurae (Ophiiira sarsi), 

 and some other bottom organisms. Alongside Macoma, another 

 widespread organism is Leionucula: at some peripheral stations 

 its biomass is equal to that of the dominant biocenosis. At 

 Stations 24. 29, 30. and others that are situated in the center of 

 the biocenosis, Macoma dominates completely; its biomass 

 equals 80-94% of the total biomass of all benthos. Maximum 

 benthic biomass at these stations reaches over 1,000 g m- 

 (Fig. 4). Average biomass of the benthos in the Macoma 

 calcarea biocenosis equals 616 g m -. 



The biocenosis Nuculana lameUosa radiata occurs in the 

 open sea, south from the Macoma biocenosis. at a depth of 

 63-88 m within the lowest temperature region in the study area. 



252 



