100 



90 



EMPTY STOMACHS 



10 



\\\\w\\\w^ 



% 



-AM- 



PM- 



Figure 18.— The proportion of stomachs containing 

 food in relation to the time of collection. 



(Wilke, Niggol. and Fiscus, 1958).^ In 1960, 

 a vessel operating in Unimak Pass and the 

 Bering Sea from 25 June to 21 August col- 

 lected 427 seals (Niggol, Fiscus, O'Brien, 

 and Wilke, 1960)/ In 1962, 1,482 seals were 

 collected in the western Alaska, Unimak Pass, 

 and Bering Sea areas from 16 May to 8 Octo- 

 ber. The results of stomach examinations are 

 shown in tables 21 to 24 by area, season, 

 volume, and frequency. 



Theragra, Mallotus. and squids have consist- 

 ently been the principal food of seals in the 

 Bering Sea. Lucas (1899) listed Theragra and 

 squids as major food items. Wilke and Kenyon 

 (1954) noted that bones and otoliths of gadids 

 are the most common material disgorged on 

 the Pribilof Islands. From 17 June to 20 July 

 1955, they collected 204 fur seals between 

 Unimak Pass and the Pribilof Islands. In 

 stomachs from seals collected near Unimak 

 Pass and the Aleutian Islands, Mallotus was 

 the dominant food item, being replaced off- 

 shore by Theragra and squids. In 1960, the 

 same food items were important in the inshore 

 and offshore areas. 



Figure 20 presents the major food items by 

 percent of volume of stomach contents and 

 percent of frequency. All food species con- 

 tributing more than 2 percent of the total 

 volume are shown. In western Alaska, squids, 

 Mallotus, and Ammodytes accounted for 94 per- 

 cent of the total food consumed in the area. 

 In Unimak Pass, Mallotus and Pleurogrammus 

 accounted for 97.1 percent of the total food. 

 In the Bering Sea, , Theragra, squids, and ,1/a/- 

 lotus accounted for 87.1 percent of the total 

 food. Combined area totals show that for the 

 seals collected in the three areas during 1962, 

 Mallotus, squids, and Theragra accounted for 

 88.2 percent of the food. 



The locations where food species occurred 

 in seal stomachs are shown in figures 21-28. 



The food of seals in the Bering Sea is better 

 known than for other areas in Alaska. Lucas 

 (1899) and Wilke and Kenyon (1954; 1957) 

 reported on food habits of fur seals in the 

 Bering Sea. The present pelagic research 

 program began in 1958, but only two seals 

 were collected in the Bering Sea that year 



In 1962, Mallotus. Theragra, and squids again 

 were leading food items. A discussion of 

 individual food items is given below. (Not 

 included are three seals collected 6 May in 

 the Gulf of Alaska about 110 miles west of 

 Cape Ommaney, containing the squid Gonatus 

 magister. and a fourth seal collected on 12 May 

 about 25 miles south of Sitkinak Island con- 

 taining T^A era^ro and a trace of Mallotus.) 



Food items . — 



Clupea harengus pallasi (herring) 



Clupea were found in nine seals collected 

 in or near Unimak Pass. Seven were collected 



^Ford Wilke. Karl Niggol. and Clifford H. Fiscus. 

 1958. Pelagic fiir seal investigations, California, 

 Oregon. Washington, and Alaska, 1958. Bureau of 

 Commercial Fisheries Marine Mammal Biological 

 Laboratory, U.S. Fish and Wildlife Service, Seattle, 

 Wash. [Processed.] 



'Karl Niggol, Clifford H. Fiscus. Thomas P.O'Brien, 

 and Ford Wilke. 1960. Pelagic fur seal investigations, 

 Alaska. 1960. Bureau of Commercial Fisheries Marine 

 Mammal Biological Laboratory, U.S. Fisli and Wildlife 

 Service. Seattle. Wash. [Processed.] 



42 



