See also:

Seal abundance
 
Polar bear abundance

Arctic Borderlands Ecological Knowledge Co-op

What is happening?

• The percentage of ringed seal pups taken in the open water harvest varies between years and can be used as an index of the population's productivity. The proportion of pups was low in the mid-1970s and recovered during the late 1970s. In 1992 and 1993 the ratio of pups was low again suggesting another decline in ringed seal productivity.

Why is it happening?

• We do not know what environmental factors cause low productivity in ringed seals for several years at a time. Current research is looking at the links between regional sea ice conditions and changes in seal productivity (Lois Harwood, DFO, personal communication). Several researchers have suggested that heavy sea ice conditions may lead to a decline in algae growth and this change, at the bottom of the food chain, may have impacts further along the food web.

Why is it important?

• Ringed seals are important to Inuvialuit in many communities and also play a role in the marine ecosystem. For example, polar bears show a preference for hunting ringed seal pups in spring. This may be because pups are abundant, easier to catch (because of their inexperience) and have a high energy value (pups have a high proportion of body fat).
• Stirling and Lunn (in press) suggest that body condition of polar bears declined in years when ringed seal pups were scarce and this was a critical factor influencing polar bear reproductive success. Tracking changes in ringed seal productivity may be a useful indicator of future changes in polar bear reproduction.

Technical Notes

• Work is currently underway (Fisheries Joint Management Committee, DFO) to collect data on the ringed seal harvest (1992-1997). The study is examining ovulation rates, age (% pups) and body condition of ringed seals harvested around Holman Island as well as regional sea ice conditions of the Beaufort Sea.
• Reference: Stirling, I. and Lunn, N.J. 1997. Environmental fluctuations in Arctic marine ecosystems as reflected by variability in reproduction of polar bears and ringed seals. In: Woodin, S.J. and Marquiss, M. (eds.) Ecology of Arctic Environments, Blackwell Science Ltd. Pp 167-181