. The Canadian field-naturalist. 504 The Canadian Field-Naturalist Vol. 110. Figure 2. Distribution of Beaided Seals in Canadian waters. on kill data collected from the Sea of Okhotsk, Fedoseev (1973) also reported an MSY of 5%. An examination of the Western Arctic data, for which conservative population indices and current kill data are available, shows that the current rate of exploita- tion probably removes no more than of the population each year. While this calculation relies on a number of assumptions and historic data for one small region of the Canadian Arctic, it suggests that th
. The Canadian field-naturalist. 504 The Canadian Field-Naturalist Vol. 110. Figure 2. Distribution of Beaided Seals in Canadian waters. on kill data collected from the Sea of Okhotsk, Fedoseev (1973) also reported an MSY of 5%. An examination of the Western Arctic data, for which conservative population indices and current kill data are available, shows that the current rate of exploita- tion probably removes no more than of the population each year. While this calculation relies on a number of assumptions and historic data for one small region of the Canadian Arctic, it suggests that the Bearded Seal populations that inhabit Canadian waters may be relatively stable. This perspective is supported by hunters who have not reported declines in sightings or catch-per-unit-effort (C. Furgal, Department of Environmental Studies, University of Waterloo, Waterloo, Ontario; L. Harwood, Department of Fish- eries and Oceans, Iqualuit, Northwest Territories; Parker; K. Seto, Department of Fisheries and Oceans, Iqaluit, NWT; personal communications). Habitat Bearded Seals prefer areas of moving ice and open water in depths of less than 150 to 200 m, and tend to avoid areas of thick shorefast ice (McLaren 1958b; Burns 1967; Mansfield 1967; Davis et al. 1975; Burns and Frost 1979; Stirling et al. 1982; Kingsley et al. 1985; Cleator and Stirling 1990). In a few areas. Bearded Seals maintain breathing holes in landfast ice throughout the winter (Mansfield 1967; Stirling and Smith 1977). This is probably because the ice in those areas freezes late and breaks up early (Stirling et al. 1983), and also because benthic pro- duction there may be high (Smith 1981). Bearded Seals have been observed in waters deeper than 500 m during March and April (Finley and Renaud 1980). They regularly use pack ice for resting, pup- ping and moulting (Fay 1974). General Biology Reproductive Capability Most males reach sexual maturity at 6 or 7 years of age (McLaren 1958a; Tikhomirov 1966; Burns 196
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