I I [ 1 I 1 1 I I I I I I 1 I I I [ I I I I I 1 I I h 



1 1 1 1 1 1 1 1 1 1 1 1 1 1 n ' 



74 



72 



70 



Ibb 



149 



143 



Figure IS. — Aerial survey tracklines flown in the western Beaufort Sea on 21 and 

 30 May 1977. No bowhead whales were seen. Dots represent presence of white 

 whales: a total of 26 whales were counted with a mean group size of l.S (SD 2.5). 



June 



1976 



In early June 1976 the bowhead whale migration along the 

 northwest coast of Alaska (Chukchi Sea) was still confined to 

 the nearshore lead. From Figure 16, however, it is evident that 

 few bowheads were present in the study area. During the 8-14 

 June (Fig. 17) aerial surveys in the southern Chukchi and 

 northern Bering Seas, two bowheads were observed just south 

 of the southern limit of the pack ice edge. They may have been 

 waiting for a lead to open, since the pack ice appeared solid 



Figure 17. — Aerial survey tracklines in the northern Bering and southern Chuk- 

 chi Seas flown on 8, 9, 10, 11, 12, 13, and 14 June 1976. The dot (highlighted by 

 an arrow) represents two bowhead whales seen just south of the ice front. One 

 whale, a large adult, remained stationary at the surface for the 5-10 min period 

 we surveyed the area. 



I II 11 I I I 1 I I 



I 1 I I I 



Chukchi 

 Sea 



72 



Figure 16. — Aerial survey tracklines flown in the eastern Chukchi and western 

 Beaufort Seas on 1,4, and 5 June 1976. Dots represent presence of bowhead 

 whales: a total of 20 whales were counted with a mean group size of 1.8 (SD 1.1). 



north of their location. By 18-20 June 1976 the bowhead mi- 

 gration along the northwest coast of Alaska was essentially 

 over; during aerial surveys flown in the nearshore leads only 

 one animal was observed (Fig. 18). 



The 1-5 June 1976 survey along the northwest coast of 

 Alaska verified that white whales were still present in the 

 Chukchi Sea (Fig. 19). On 1 June, 153 white whales were 

 observed at lat. 70°59'N, long. 158°41'W. All other sight- 

 ings were of 12 or fewer whales. 



Eighteen adult white whales were sighted near the mouth 

 of the Yukon River on 14 June 1976 (Fig. 20). White whales 

 were not encountered elsewhere during the survey, which 

 suggests that most had left the north Bering Sea by June and 

 that the Yukon Delta sightings were of a group which sum- 

 mers in Norton Sound. 



The Chukchi and Beaufort Seas were again surveyed 18-20 

 June 1976 (Fig. 21). Only two sightings of white whales were 

 made: 12 adults were observed at lat. 70°39'N, long. 161°47'W 

 on 19 June, and 49 adults with 12 immatures were observed 

 at lat. 69°28'N, long. 164° 10' W on 20 June. 



13 



