POPULATION DYNAMICS AND EXPLOITATION OF 

 SEALS IN THE EASTERN CANADIAN ARCTIC 



I. A. McLaren 



Fisheries Research Board of Canada, Arctic Unit 



and 



Department of Zoology, Yale University 



Five species of seals are found in the eastern Canadian Arctic. Of these, the 

 Harp Seal {Pagophilus groenlandicus) is an abundant summer migrant, but is 

 not often killed by the Eskimos of most regions. The Hooded Seal {Cysto- 

 phora cristata) is a rare migrant to the north-east Arctic; the Harbour or 

 Common Seal {Phoca vitulina) is a rare and local resident throughout the 

 more southerly Arctic. Only the two remaining species are common and of 

 economic importance at present. The ubiquitous Ringed Seal [Phoca hispida), 

 which is generally less than 5 ft long, forms or once formed the basis of the 

 economy of almost all coastal Eskimos. The Bearded Seal [Erignathus barhatus) 

 is a considerably larger species, up to about 8 it long; it is far less common, 

 but is much prized for its meat and for its hide, which is used in making 

 boots, skin lines, and other Eskimo products. 



A brief account of the pertinent aspects of the life histories of these two 

 species will be given first as a necessary background to the bionomical 

 considerations which will follow. Two papers by the author (McLaren, 

 1958^, igsSb) support and elaborate the biological conclusions offered here. 

 The geographical names referred to in the text may be found on Fig. i. 



OUTLINE OF THE LIFE HISTORIES OF RINGED AND BEARDED 



SEALS 

 Accurate methods of age determination have laid the basis of our under- 

 standing of the life histories and bionomics of these seals. The ringed seal 

 may be aged by means of dentinal annuh in the teeth (Laws, 1953) and the 

 bearded seal by bands on the claws (Plekhanov, 1933)- Both tooth and claw 

 patterns depend on annual metabolic interruptions caused by fasting, the 

 moult, and other coincident drains on the animal. Unfortunately, due to 

 wear at the tip, the claws cease to be useful a few years after maturity. 

 The feeding of these seals has been studied in detail. The ringed seal takes 



