Part II. PELAGIC FUR SEAL INVESTIGATIONS, 1968 



The objectives of pelagic research in 1968 

 were: (1) to collect information on the distri- 

 bution of fur seals in winter, including the 

 arrival time of the year classes, and their 

 feeding habits off Washington; and (2) to re- 



survey migration, distribution, and feeding 

 habits of fur seals in waters of western Alaska 

 with special emphasis on collecting young 

 females for studies of reproductive condition 

 in late spring and summer. 



RESEARCH IN 1968 



We carried out our investigations off Wash- 

 ington from 27 Novennber to 21 December 1967 

 and from 2 January to 26 February 1968. In- 

 vestigations were conducted in Alaska waters 

 from 18 May to 25 August. The M/V Tonquin' ^ 

 was chartered for the cruise (No. 29) off Wash- 

 ington and the M/V New St. Joseph ^ for the 

 cruise (No. 30) in Alaska waters. Table C-1 

 shows participants and their itineraries. Ka- 

 zumoto Yoshida from the Japanese Fishery 

 Agency observed pelagic sealing methods 

 aboard the M/V New St. Joseph from 10 June 

 to 2 July 1968. 



Equipment and methods used to collect and 

 examine seals are described in previous re- 

 ports (Fiscus, Baines, and Wilke, 1964;Fiscus 

 and Kajimura, 1967). 



Sonar (Western Marine Electronics [Wes- 

 mar] Horizontal-scan sonar model SS200) was 

 installed in the Tonquin so that the equipment 

 could be evaluated for use in locating and 

 tracking fur seals. Factory representatives 

 calibrated and demonstrated use of their sonar 

 during the cruise. We concluded, however, that 

 sonar is currently of no advantage in pelagic 

 fur seal research. Seals encountered during 

 tests of the equipment behaved normally; they 

 were usually lying on the surface when sighted, 

 and dived and changed course rapidly when ap- 

 proched and disturbed. We found it extremely 

 difficult to find a seal on the surface by sonar 

 because we could not separate surface and 

 wave returns from seals on the sonar screen. 

 Air bubbles in the vessel's wake were detected 

 and shown on the screen. They forn-ied an ef- 

 fective barrier to sonar through which a seal 

 could escape undetected. Seals below the sur- 

 face were apparently detected just after they 

 dived, but most disappeared rapidly from the 

 screen when followed. The sonar operator could 

 then only scan in the direction the seal appeared 

 to be traveling, a futile effort in each instance. 



DISTRIBUTION OFF WASHINGTON 



Seals were present off Washington in late 

 November and in early December. Their nun^- 



bers increased along the Continental Shelf in 

 the second and third week of December. In 

 January and February seals were abundant 

 along the Continental Shelf from Grays Harbor 

 to the Columbia River and present in lesser 

 numbers from Grays Harbor northward along 

 the shelf to Cape Flattery. Figures 10 to 13 

 and tables C-2 to C-5 show the distribution of 

 seals. 



DISTRIBUTION IN ALASKA WATERS 



Figures 14 to 18 and tables C-6 to C- 1 1 show 

 the distribution of seals in areas we surveyed 

 from the New St. Joseph . A concentration of 

 seals (105 sighted) was found on 21 May in the 

 eastern Gulf of Alaska. 



We cruised the western Gulf of Alaska and 

 waters off Kodiak Island the last of May but 

 failed to locate any concentrations of seals 

 where they were in previous years. Only 21 

 animals were sighted on 1-2 June west from 

 Kodiak Island toward the Shumagin Islands. We 

 saw seals south of the Shumagin Islands on 

 3-4 June. We found concentrations of seals on 

 17-18 and 27-28 June south and east of Akutan 

 Pass while working south of the eastern Aleu- 

 tian Islands 6-30 June. 



The M/V Pribilof* carried U.S. observers 

 from the Pribilof Islands to Medny Island, 

 Commander Islands, and back between 26 June 

 and 10 July 1968. One to three observers 

 watched for seals during most daylight hours; 

 the officers and crew of the Pribilof assisted. 

 Figure 19 shows the daily run and seals sighted. 



Seals were abundant on 6 July near Medny 

 Island but most of the seals seen were sighted 

 on 27 June and 9 July off the Continental Shelf 

 148 to 370 km. (80-200 miles) from the Prib- 

 ilof Islands. Only three seals were seen north 

 of the western Aleutian Islands. 



We surveyed the Bering Sea and the Pacific 

 Ocean near the eastern Aleutians in July. No 

 concentrations of seals were located vintil 21 

 July, when 78 were sighted north of Akutan 

 Island. 



"^ Registered length 29.4 m. (96.6 feet), 200 net tons, 350 

 horsepower, cruising speed 16.7 km. per hour (9 knots). 



' Registered length 22.4 m. (73.6 feet), 53 net tons, 340 

 horsepower, cruising speed 18.5 km. per hour (lOknots). 



^ Bureau of Commercial Fisheries Pribilof Islands sup- 

 ply vessel; registered length 64 m. (210 feet), 1,200 gross 

 tons, 14,000 horsepower, cruising speed 22.2 km. per 

 hour (12 knots). 



34 



