Pelagic Fur Seal Investigation, 1964 



By 



CLIFFORD H. FISCUS, Wildlife Biologist and 

 HIROSHI KAJIMURA, Fishery Biologist 



Bureau of Commercial Fisheries 



Marine Mammal Biological Laboratory 



Seattle, Washington 



ABSTRACT 



The seventh year of pelagic research on the fur seal ( Callorhinus ursinus ), 

 under the terms of the Interim Convention on Conservation of North Pacific Fur 

 Seals was carried out off California, Oregon, and Washington from 7 April to 1 June, 

 and in the Bering Sea from 4 July to 8 September 1964. Seals collected off Cali- 

 fornia totaled 305; off Oregon, 10; off Washington, 28; and in the Bering Sea, 533. 

 Fewer seals were seen off California in April and May 1964 than during similar 

 research in January to March in 1958, 1959, and 1961; young females formed a 

 larger proportion of the collections in 1964 (21-30 percent) than in previous years 

 (10, 9, and 15 percent); 76 percent of the total males taken in all 4 years off Cali- 

 fornia were collected in 1964. Summer distribution of seals in the Bering Sea was 

 similar to that m 1962 and 1963. Females, predominantly mature, made up 91 

 percent of the Bering Sea collections. The percentage of tagged seals in pelagic 

 samples increased progressively from 0.9 in 1958 to 4.9 in 1964. A seal tagged 

 by the U.S.S.R. and recovered by a U.S. vessel was collected on 28 August about 

 60 miles northeast of St. Paul Island. The pregnancy rate (76.4 percent) was lower 

 than in previous years because samples were taken off California during a period 

 when a higher proportion of nuUiparous and nonpregnant females were present. 

 Gooseneck barnacles ( Lepas sp.) and algae ( Ectocarpus sp.) growing on the guard 

 hairs of seals were more common in the spring of 1964 than in winter collections 

 of other years. Thirty-three food species were identified in 876 stomachs in 1964. 

 Merluccius productus was the major food off California, Oregon, and Washington. 

 Squids, Clupea harengus pallasi, Theragra chalcogrammus , Bathylagidae, and 

 Mallotus villosus were the leading foods in the Bering Sea. 



INTRODUCTION 



This report contains information on the 

 seventh year of pelagic fur seal research by 

 the United States under the Interim Convention 

 on Conservation of North Pacific Fur Seals. 



The first of two phases of the investigation 

 in 1964 was on the distribution, abundance, 

 migration, and feeding habits of fur seals off 

 California, Oregon, and Washington in April 

 and May; the second was on the occurrence 

 and feeding of fur seals m Bering Sea in July, 

 August, and early September. Reproductive 

 condition of females was also studied. 



Work off California was concluded by mid- 

 April in previous years. The extension of 

 observations to late May in 1964 provided 

 additional information on late migration and 

 movement. 



In the Bering Sea, information was obtained 

 on the area north from the Aleutian Islands 

 to the Pribilof Islands, and on the feeding 

 grounds to the east, north, and west of the 

 Pribilof Islands. 



METHODS, EQUIPMENT, AND 

 ITINERARY 



Vessels and equipment, and methods used 

 in hunting and in the collection of data from 

 seals killed, were described by Fiscus, Baines, 

 and Wilke (1964). Briefly, seals were sighted 

 from the vessel (or, during calm weather, 

 from small boats accompanying it); shot with 

 12-gauge shotguns; and weighed, measured, 

 examined, and skinned. Age was determined 

 by counting annuli on longitudinal sections of 



