thin ice coverage was extensive. North of the island there was 

 nearly 90% ice coverage and pack ice was thick. No bowhead 

 whales were observed. White whales were most common just 

 northwest of St. Lawrence Island (Fig. 5). 



During the 6-23 April 1976 survey pack ice was thick be- 

 tween lat. 64° and 65°N in the vincinity of St. Lawrence Island. 

 South of lat. 64°N pack ice was of medium thickness. Ice 

 coverage at this time of year was still extensive: 70-100%; 

 80% coverage was most common. Large expanses of 100% 

 coverage occurred northwest of St. Matthew Island. South- 

 east of St. Matthew Island, and in Bristol Bay, sea ice was 

 extensive to the southern limit indicated by aerial survey 

 tracklines (Fig. 6). 



No bowheads were seen during the 6-23 April 1976 survey 

 in Bristol Bay (Fig. 6)'\ Three bowheads were observed in 

 the northern Bering Sea, one on 19 April about 20 km south 

 of Little Diomede Island (Bering Strait), migrating north- 

 easterly in a lead. 



White whales were observed most often in the region from 

 northwest of St. Lawrence Island to the Bering Strait during 

 the 6-23 April 1976 survey (Fig. 7). Twenty-five white whales, 

 18 adults with 7 presumed immatures (grey skin) were seen 

 on 9 April in Bristol Bay (Fig. 7). 



1977 



In the region near St. Lawrence Island, aerial surveys were 

 flown 31 March-3 April 1977 (Fig. 8). No bowheads were ob- 

 served in Norton Sound, but a pair was observed southwest of 

 St. Lawrence Island and another, or one of a pair, observed 

 later in the same area. Two more were observed in the lead just 

 southeast of the Bering Strait. 



During the 31 March-3 April 1977 surveys white whales were 

 most common north and west of the west end of St. Lawrence 

 Island, and in a large polynya off the coast of the Seward 

 Peninsula (Fig. 9). 



"One bowhead was observed on 9 April 1976 west of (he Pribilof Islands by 

 Patrick McGuire. National Marine Mammal Laboratory, from the NOAA ship 

 Surveyor. 



May 



1976 



Results from the 30 April to 14 May 1976 (Fig. 10) and the 

 15 to 31 May 1976 (Fig. 11) aerial surveys indicate that the 



157 



175 



Figure 6. — Aerial survey tracklines flown on 6. 8. 9. 12, 13, 15, 17, 18, 19, 20,21, 

 22, and 23 April 1976. Each of the three dots represent a sighting of a bowhead 

 whale. No bowheads were observed below lat. 63° N. 



Figure 7. — Aerial survey tracklines flown in the Bering Sea on 6, 8, 9, 12, 13, 15, 

 17, 18, 19, 20, 21, 22, and 23 April 1976. Dots depict presence of while whales: a 

 total of 135 were counted with a mean group size of 5.4 (SD 6.2). 



10 



