Table 20. — List of taxa included in the analysis of species associations, 

 1976 Bering Sea spring trawl survey. 1 



Taxon 



Common name 



Raja spp. 



Clupea harengus pallasi 



Mallotus villosus 



Osmerus mordax 



Thaleichlhys pacificus 



Boreogadus saida 



Eleginus gracilis 



Gadus macrocephalus 



Theragra chalcogramma 



Lycodes palearis 



Coryphaenoides spp. 



Trichodon trichodon 



Balhymaster signatus 



Lumpenus sagiita 



Anarrhichthys ocellatus 



Anarhichas orientalis 



Ammodytes hexapterus 



Sebastes aleutianus 



S. aluius 



Sebastolobus alascanus 



A noplopoma fimbria 



Hexagrammos stelleri 



Dasycotlus seliger 



Hemilepidotus hemilepidotus 



H. jordani 



Icetus spiniger 



Melleles papilio 



Myoxocephalus polyacanthocephalus 



Triglops pingeli 



Hemitripterus bolini 



Agortus acipenserinus 



Careproctus rastrinus 



Eumicrotremus orbis 



Atheresthes stomias 



Glyptocephalus zachirus 



Hippoglossoides elassodon 



H. robustus 



Hippoglossus stenolepis 



Lepidopsetta bilineata 



Limanda aspera 



L. proboscidea 



Microstomas pacificus 



Platichthys stellatus 



Pleuronectes quadrituberculatus 



Reinhardiius hippoglossoides 



Octopus spp. 



Crangon communis 



C. dalli 



Pandalopsis dispar 



Pandalus borealis 



P. goniurus 



P. monlagui tridens 



Chionoecetes angulatus 



C. bairdi 

 C. opilio 

 Chionoecetes sp. 

 Hyas coarctatus almaceus 

 Hyas lyratus 

 Oregonia gracilis 

 Erimacrus isenbeckii 

 Lithodes aequispina 

 Paralithodes camtschatica 

 P. platypus 



Unidentified skates 

 Pacific herring 

 Capelin 

 Rainbow smelt 

 Eulachon 

 Arctic cod 

 Saffron cod 

 Pacific cod 

 Walleye pollock 

 Wattled eelpout 

 Unidentified rattails 

 Pacific sandfish 

 Searcher 



Snake prickleback 

 Wolf-eel 

 Bering wolffish 

 Pacific sand lance 

 Rougheye rockfish 

 Pacific ocean perch 

 Shortspine thornyhead 

 Sablefish 



Whitespotted greenling 

 Spinyhead sculpin 

 Red Irish lord 

 Yellow Irish lord 

 Thorny sculpin 

 Butterfly sculpin 

 Great sculpin 

 Ribbed sculpin 

 Bigmouth sculpin 

 Sturgeon poacher 

 Pink snailfish 

 Pacific spiny lumpsucker 

 Arrowtooth flounder 

 Rex sole 

 Flathead sole 

 Bering flounder 

 Pacific halibut 

 Rock sole 

 Yellowfin sole 

 Longhead dab 

 Dover sole 

 Starry flounder 

 .Alaska plaice 

 Greenland turbot 

 Unidentified octopus 



Sidestripe shrimp 

 Pink shrimp 

 Humpy shrimp 



Snow (Tanner) crab 



(angulatus) 

 Snow crab (bairdi) 

 Snow crab (opilio) 

 Snow crab (hybrid) 



Elbow crab 

 Decorator crab 

 Korean horsehair crab 

 Golden king crab 

 Red king crab 

 Blue king crab 



See Figure 22. 



ing the 1976 survey. The distribution patterns of group occur- 

 rences were regional with limited geographical overlap and were 

 similar to results from the 1975 Bering Sea survey (Pereyra et al. 

 see footnote 2). The associations and distributions defined by the 

 groups follow. 



Group 1 (outer shelf group): The 10 species of group 1 (Fig. 

 22) individually showed broad distribution patterns, ranging from 

 north to south limits of the survey area and from inner Bristol Bay 

 to the outer continental slope. In contrast to the extended ranges 

 of the individual species, the occurrences of group 1 members 

 together were restricted to 92 stations (depths 100-185 m) along 

 the outer continental shelf (Fig. 23). 



Group 2 (central shelf group): Group 2 consisted of five fish 

 species, plus one associated crab species, that were broadly 

 distributed over the central Bering Sea continental shelf. The two 

 most abundant species, yellowfin sole and Alaska plaice, were ap- 

 parently migrating from deep to shallow water during the survey. 

 Group 2 members occurred together at 62 stations in a large mid- 

 shelf region between bottom depths of approximately 30-80 m 

 (Fig. 24). 



Group 3 (northern outer shelf group): The three fish species 

 of group 3 occurred as an isolated northern group, showing no af- 

 finities to members from any other recurrent group. Group 3 

 members occurred together at 13 stations (depths 84-110 m) be- 

 tween lat. 58 c 45' and 60°00'N, directly south of St. Matthew 

 Island (Fig. 25). 



Group 4 (southern deepwater group): Group 4 was com- 

 posed of three flatfish species that occurred together at 50 stations 

 in deep water (depths 1 15-450 m) along the outer continental shelf 

 and slope (Fig. 26). 



Group 5 (Alaska Peninsula group): The two flatfish and one 

 crab species of group 5 occurred together at 49 stations primarily 

 in a broad area along the Alaska Peninsula between bottom 

 depths of approximately 18-65 m (Fig. 27). 



Similarities between the recurrent species groupings observed 

 during the 1976 spring trawl survey, and those of Pereyra et al. 

 (see footnote 2), support the hypothesis that the Bering Sea 

 demersal fish and shellfish community can be characterized by a 

 few major, large-scale organizational features. A relatively small 

 number of principal species accounts for most of the trawlable 

 biomass. These species apparently show recurrent, although 

 seasonally influenced, patterns of association within relatively well 

 defined geographical regions of the Bering Sea continental shelf 

 and slope. 



Distribution, Abundance, and Biological 

 Characteristics of Principal Fish Populations 



Walleye pollock. 



Distribution and abundance. — Walleye pollock were widely 

 distributed throughout the survey area, occurring at 335 (77.0%) 

 of the 435 grid trawling stations, at an overall mean abundance of 

 34.00 kg/km trawled. Regions of highest abundance by weight 

 were along the outer continental shelf (subareas 2, 3N, and 3S) 

 west and southeast of the Pribilof Islands (Table 21, Fig. 28). 

 Large numbers of juvenile walleye pollock (age 1 yr) were ob- 

 served in regions of the inner continental shelf (subareas 1, 4S, 

 and 4N), although their estimated total biomass was relatively 

 low. 



33 



