Polar Bear Abundance
Arctic Borderlands Ecological Knowledge Co-op
What is happening?
- Relative abundance of ringed seals varied over the four years of the study and was highest in 1982. In most years ringed seals were clumped in large areas; over the years of the study these aggregation areas varied in size, number (1 in 1984, 2 in 1982 and 3 in 1986) and location. The aggregation areas in late summer were most often north of the Tuktoyaktuk Peninsula.
Why is it happening?
- Recruitment of ringed seal pups appeared to be low in 1984 as reported by hunters from Sachs Harbour. Recruitment stayed low between 1984 and 1987; the reasons are uncertain but researchers noted that the decline coincided with heavy ice conditions in the summer of 1985.
Why is it important?
- Ringed seals are an important part of the diet of polar bears and declines in the productivity of ringed seals (e.g. 1974-75 and 1985-1987) translated into decline in productivity of polar bears. One way of tracking future changes in polar bear populations might be to monitor the recruitment of ringed seal pups, an important part of the bear's diet.
- The estimates of seal numbers are based on aerial survey flights in August and September and reflect relative abundance because it was not possible to correct for seals that were either missed at the surface or were underwater.
- Reference: Lois Harwood and Ian Stirling 1992. Distribution of ringed seals in the southeastern Beaufort Sea during late summer. Can. J. Zool. 70:891-900.