species with its center of abundance in the Bering Sea (along 

 the Aleutian Islands) or Arctic Ocean (Hart and McHugh 

 1944). Capelin are a bathypelagic (benthopelagic) fish during 

 most of the year and are located near the bottom, moving in- 

 shore as the spawning period approaches (Andriyashev 1954; 

 Trumble 1973; Macy et al. 1978 18 ). In some parts of the range, 

 capelin spawn from April to October, spawning on beaches 

 composed of fine gravel at high tide. In southern British Co- 

 lumbia, this fish spawns in late September and/or early Octo- 

 ber (Hart and McHugh 1944; Hart 1973). 



Capelin ranked 17th by frequency of occurrence (•%) of the 

 20 most common taxa in the eastern Bering Sea survey con- 

 ducted in 1975 (Pereyra et al. footnote 13). Little is known as 

 to the relative abundance of capelin in the Bering Sea but the 

 species was observed in large numbers along the Alaska coast 

 in shallow water at about the same time as spawning Pacific 

 herring (Barton and Steinhoff 1980). Based on the analysis of 

 fur seal feeding studies and because it is also an important link 

 in the food chains of the North Pacific and Bering Sea for 

 many fishes, marine mammals, and seabirds (Ainley and San- 

 ger 1979; Kawamura 1980; Kajimura et al. 1980), capelin is 

 probably a large and important resource in the North Pacific 

 Ocean and associated seas. Based on an ecosystem model, 

 Laevastu and Favorite (1980) estimated the pelagic fish spe- 

 cies, consisting primarily of capelin and Pacific sand lance, 

 biomass to be 4.3 million t for the Bering Sea. Capelin was also 

 found in stomachs of humpback whales (Nemoto 1957). Cape- 

 lin is not fished commercially but is considered an excellent 

 food by those who capture them on the spawning beaches. 



During an ichthyoplankton survey of the Bering Sea in 1977, 

 capelin was the only smelt collected and its larvae were among 

 the largest caught, ranging from 31 to 65 mm in length. The 

 larvae are known to move offshore to deeper water after 

 hatching but little is known of the deepwater phase of the life 

 cycle of this fish. Eighty-six percent of the capelin were caught 

 at night, primarily over the continental shelf within about 140 

 km (75 mi) of Unimak Pass. The larvae of this species were the 

 sixth most abundant taken (Waldron and Vinter footnote 14). 



"Macy, P. T., J. M. Wall, N. D. Lampasakis, and J. E. Mason. 1978. Resources 

 of non-salmonid pelagic fishes of the Gulf of Alaska and eastern Bering Sea, Pan 

 1. Unpubl. manuscr., 335 p. Northwest and Alaska Fish. Cent., Natl. Mar. Fish. 

 Serv., NOAA. 2725 Montlake Blvd. E., Seattle, WA 981 12. 



Atka mackerel. — Atka mackerel was second only to capelin 

 as the principal forage species based on percentage of total 

 stomach content volume for seals collected in Unimak Pass 

 and beyond the shelf area between the Aleutian and the Pribi- 

 lof Islands during 1962 (Fiscus et al. 1964). When sampling 

 was limited to a distance of 55 km around the Pribilof Islands 

 in 1974, Atka mackerel was the third ranking principal forage 

 species of fur seals. This species was found in the stomachs of 

 seals taken south and west of St. George Island along the shelf 

 edge in 1974 (Fig. 31). 



Atka mackerel is distributed from off California northward 

 to the Bering Sea and in the Sea of Japan (Miller and Lea 

 1972). During the breeding season it is concentrated in waters 

 off the Aleutian Island chain from Attu to Unimak Islands, 

 the Alaska Peninsula, the Shumagin Islands, and Kodiak Is- 

 land and is widespread in the open ocean at other times. Ever- 

 mann and Goldsborough (1907) reported that at Atka Island 

 the larger males arrive first in May to await the females' arrival 

 on the spawning grounds which is always near the various 

 passes in the Aleutian Islands. They also reported that sea 

 lions, killed at various times throughout the winter, frequently 

 had stomachs filled with Atka mackerel, an indication that 

 some fish stay near the Aleutian passes year-round. Larkins 

 (1964) reported Atka mackerel catches incidental to high seas 

 salmon gillnet sampling as the fourth most abundant species 

 caught. Chum, Oncorhynchus keta, sockeye, O. nerka, and 

 pink salmon, O. gorbuscha, were numbers 1, 2, and 3, respec- 

 tively. Atka mackerel catches were more abundant in gillnet 

 catches in the southern Bering Sea-Aleutian areas than in the 

 northern or southern portion of the Gulf of Alaska. 



Ichthyoplankton surveys in 1955-78 were summarized by 

 Waldron (1981) who reported that Atka mackerel larvae were 

 caught at 1 18 stations on 1 1 cruises in winter, spring, and sum- 

 mer from late February to August. These larvae were distrib- 

 uted from the Aleutian Islands to lat. 62°N and from long. 

 160°W in Bristol Bay to long. 175°E. In 1977, larvae of the 

 family Hexagrammidae were the second most numerous larvae 

 caught with Atka mackerel larvae consisting of about 29% of 

 the Hexagrammidae catch (Waldron and Vinter footnote 14). 

 The larvae were relatively large, ranging from 12 to 30 mm in 

 length, and were caught at stations throughout the survey area 

 during April and May over the shelf and extending well 

 beyond the continental slope. The highest abundance was 



♦ 



* 



t Pribilof Is. 



f 



A 











+ 





Bering Sea 



♦ ♦ * a <Tr- 



>s 





■H- ,4X- 



°*- ^* 







4* 



I , 



— i i i 



III 



Figure 31. — Locations where 133 northern fur seals were collected whose stomachs contained Atka mackerel, 195&-74. 



25 



