FISHERY BULLETIN: VOL. 83, NO. 3 



BEAUFORT 



SEA ^ / 



Tuktoyaktuk 

 Kugmallit Bay 

 N.W.T. 



100 



I30*» 



Figure l.-The eastern Beaufort Sea. 



Stall speed. An OnTrac VLF/Omega navigation 

 system indicated the latitude and longitude. A hand- 

 held color video camera (JVC-CV-0001 in 1980 and 

 1981, Sony HVC-2000 in 1982) connected to a por- 

 table video cassette recorder (Sony SLO-340 in 1980 

 and 1981, Sony SL-2000 in 1982) was used through 

 the side windows to record oblique views of 

 bowheads. 



Our usual strategy was to search until we encoun- 

 tered bowheads, and then circle over them as long as 

 possible while making observations. If contact was 

 lost, we searched for another group. We created a 

 fixed reference point about which to circle when 

 bowheads were below the surface by dropping a 

 fluorescein dye marker. Near the start of most 

 periods of circling above whales, a sonobuoy 



(AN/SSQ-41B or AN/SSQ-57A) was dropped to 

 broadcast underwater sounds to the aircraft, where 

 they were recorded. 



In 1980-82, we flew for a total of 340 h during 71 

 offshore flights. Of this time, we circled over bow- 

 heads for 97.7 h during 46 flights. Flight duration 

 was typically 4-5.5 h. Flights were made between 3 

 and 31 August 1980, 31 July and 8 September 1981, 

 and 1 and 31 August 1982. We encountered bow- 

 head whales during every day we flew in 1980, and 

 during the majority of days in 1981 and 1982. 



We usually did not fly when wind speed exceeded 

 25 km/h; in more severe conditions whales are dif- 

 ficult to detect and behavior cannot be observed 

 reliably. While searching for whales, we usually flew 

 at 457-610 m (1,500-2,000 ft) above sea level (ASL), 



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