Distribution and Numbers of Bowhead Whales (<i>Balaena mysticetus</i>) in Northwestern Hudson Bay in August 1995

Abstract

ABSTRACT. There is interest among the Inuit of Nunavut in renewing subsistence hunting of bowhead whales. Managing a limited harvest while allowing for stock recovery from commercial whaling requires some estimate of stock numbers. The large geographic range of bowhead whales in the eastern Canadian Arctic precludes cost-effective estimation of total stock size; however, estimates of summer aggregation sizes can be derived from sampling of summering areas. Although these numbers do not represent total stock size, they do provide indicators of the minimum number of bowheads known to be present and may be useful as indices for monitoring stock recovery. A visual aerial survey conducted in northwestern Hudson Bay resulted in an estimate of 75 ± 27.5 (95% Confidence Interval = 17-133) bowhead whales. This estimate is conservative because it was not corrected for submerged whales or for whales that were at the surface but not seen by observers. Most sightings of whales were made in Repulse Bay and Frozen Strait.Key words: aerial survey, bowhead whale, distribution, northwestern Hudson Bay, stock size RÉSUMÉ. Parmi les Inuit du Nunavut, on s'intéresse à reprendre la chasse de subsistance à la baleine boréale. La gestion d'une récolte limitée, qui permettrait au stock de baleine boréale de se rétablir des effets de la pêche commerciale, demande qu'on ait une idée du nombre d'individus qui composent cette population. L'ampleur du territoire géographique de la baleine boréale dans l'Arctique canadien oriental écarte la possibilité de réaliser une estimation du nombre total d'individus, qui soit efficace en terme de coûts; il est cependant possible de dériver des estimations de la taille des concentrations estivales à partir d'échantillonnages de zones d'estivage. Bien que ces nombres ne représentent pas la taille totale du stock, ils fournissent des indications sur le nombre minimum de baleines boréales dont on a attesté la présence et ils peuvent servir d'indicateurs pour la gestion du rétablissement du stock. Un relevé visuel aérien mené dans le nord-ouest de la baie d'Hudson a donné une estimation de 75 ± 27,5 (intervalle de confiance de 95 p. cent = 17-133) baleines boréales. Cette estimation est prudente car elle n'a pas été corrigée pour tenir compte des baleines submergées ou de celles qui étaient en surface mais qui n'auraient pas été aperçues par les observateurs. La plupart des observations de baleines ont été faites à Repulse Bay et Frozen Strait.Mots clés: relevé aérien, baleine boréale, distribution, nord-ouest de la baie d'Hudson, taille du stock Traduit pour la revue Arctic par Nésida Loyer.

Bowhead whale Balaena mysticetus seasonal selection of sea ice

“…In spring, bowhead whales move from their winter range to the west coast of Greenland, Foxe Basin, Cumberland Sound, and the entrance to Lancaster Sound. During the summer, bowhead whales are known to be widely distributed in the fjords and bays of the Canadian High Arctic, in Hudson Bay, Foxe Basin (Cosens et al 1997, Cosens & Innes 2000, the Gulf of Boothia and Prince Regent Inlet (L. Dueck et al unpubl. data).…”

Offshore Distances of Bowhead Whales (<i>Balaena mysticetus</i>) Observed during Fall in the Beaufort Sea, 1982–2000: An Alternative Interpretation

“…Our methods are unbiased relative to survey effort or sighting conditions (Cosens et al, 1997;Cosens and Innes, 2000) and results are representative of actual distributions of fall bowhead whales using nearshore (70˚ to 72˚ N) waters in the central Alaskan Beaufort Sea (but see Moore, 2000;Moore et al, 2000). Since we were not interested in deriving density or population estimates, any biases related to survey methodology are reduced (Eberhardt, 1978;Burnham et al, 1980).…”

“…We recognize the potential for sex-and agespecific segregation to occur either spatially or temporally during fall migration of bowhead whales in the Beaufort Sea (Braham, 1995;George et al, 1995;Cosens and Innes, 2000; but see Moore and Reeves, 1993:351). However, the monitoring protocol precluded an analysis of differences in migration axes relative to sex-age cohorts.…”

Dolphins, whales and porpoises : 2002-2010 conservation action plan for the world's cetaceans

“…Range-wide abundance is thought to be in the order of 10,000 individuals, with 8200 (7200-9400) in the BeringChukchi-Beaufort Seas (IWC 1996, based on Zeh et al 1995), at least 350 in Davis Strait-Baffin Bay (Zeh et al 1993), 284 ± 49 in Hudson Bay-Foxe Basin (Cosens et al 1997), 100 or less in Svalbard-Barents Sea (Zeh et al 1993), and 150-200 in the Okhotsk Sea (Zeh et al 1993). All bowhead populations were severely depleted by commercial whaling, which began in the north-eastern Atlantic in the 1600s.…”

“…The purpose of this project is to encourage more intensive research on bowhead whales in eastern Canadian and western Greenland waters (the Davis Strait/Baffin Bay stock moves between the two countries). It is important that initial efforts to estimate abundance (Cosens et al1997;Cosens and Innes 2000) and determine the genetic distinctiveness of whales in the two stock areas (Maiers et al 2001;Rosenbaum et al 2001a) be continued and expanded, and that factors potentially relevant to conservation, in addition to deliberate removals by whaling, be thoroughly examined. Moreover, it is important that results of the research that forms the basis for hunt management be subjected to peer scrutiny, and that Canada's management regime for these stocks be risk-averse.…”