Shrnutí

Popis

Bowhead whales were documented during their spring migration most years from 1979 to 1992 by biologists from NMML. This documentation consisted of flying aerial surveys in an area generally north and east of Barrow, Alaska, (avoiding whaling operations to the west) to record sighting information and conduct vertical photography of the whales. Flight lines were sometimes on systematic transects perpendicular to the nearshore ice edge, providing an offshore distribution of whales (used in calculating the proportion of the population within sighting range of ice-base observation teams). Often, the flight lines were not prescribed, following instead the openings in sea ice (leads) to maximize opportunities for finding whales. These latter surveys were designed primarily for aerial photography, which provides information on individual, recognizable whales and, through photogrammetry, provides lengths of whales.