Distribution and numbers of Canadian High Arctic narwhals (Monodon monoceros) in August 1984

Abstract

Aerial photographic surveys of the numbers and distribution of narwhals (Monodon monoceros) in fjords and inlets south of Parry Channel, N.W.T., Canada, were conducted between 17 and 29 August 1984. Narwhals were concentrated in waters 350 m or more in depth and were most abundant in Prince Regent Inlet and Admiralty Inlet.

An estimate of 18 000 narwhals (90% Cl 15 000- 21 000) was obtained by combining estimates for the Eclipse Sound area, Admiralty Inlet, Prince Regent Inlet and Peel Sound. We evaluated the visibility of narwhal and white whale (Delphinapterus leucas) models submerged to different depths. Models of adult narwhals could be seen when submerged to I 0 m but could only be clearly distinguished from white whales at depths of 2 m. Such results indicate a limit to counting submerged narwhals. This problem, along with other factors, constrains the estimation of population size.