An aerial line-transect survey was carried out in Russia and Norway in 2004. Population estimate is 2,650. The trend of the subpopulation is unknown.
Status table outtake
|
Aerial survey / Mark-recapture analysis |
Additional / Alternative Analysis |
|||||||||||
| Number (year of estimate) |
±2 SE or 95% CI |
Number (year of estimate) |
±2 SE or min-max range |
Sim | TEK | Historical annual removals (5 yr mean) | Potential maximum annual removals | Status | Current trend | Estimated risk of future decline | ||
| 2650 (2004) | 1900-3600 | 1 | 0 | Data deficient | Data deficient | Data deficient | ||||||
Table comment: Population estimate is based on a new aerial survey. There was likely an increase in the subpopulation size after 1973 until recently. Current growth trend is unknown.
The size of the Barents Sea (BS) subpopulation was estimated using aerial survey techniques to be approx. 2,650 (95% CI, approx. 1900 – 3600) in August 2004 (Aars et al. 2009). This suggests that earlier estimates based on den counts and ship surveys (Larsen 1972) were too high. This suggestion is further supported by ecological data that indicate the subpopulation grew steadily the first decade after protection from hunting in 1973, and then either continued to grow or stabilized. Studies on individual movement using satellite telemetry and mark-recapture have been conducted in the Svalbard area since the early 1970s (Larsen 1972, 1985, Wiig 1995, Mauritzen et al. 2001, 2002) and continue. Studies show that some polar bears associated with Svalbard are very restricted in their movements but bears from BS, specifically, range widely between Svalbard and Franz Josef Land (Wiig 1995, Mauritzen et al. 2001). Continuing research confirms there is some spatial substructure between bears in northern and southern Svalbard. Some bears of the pelagic-type from northern Svalbard, move north to the Arctic Ocean in the summer, and return to northern Svalbard in the winter, whereas bears from southern Svalbard follow retreating ice to the east. Subpopulation boundaries based on satellite telemetry data indicate that BS is a natural subpopulation unit, albeit with some overlap to the east with the Kara Sea subpopulation (Mauritzen et al. 2002). Although overlap between BS and the East Greenland subpopulation may be limited (Born et al. 1997), low levels of genetic structure among all these subpopulations indicates substantial gene flow (Paetkau et al. 1999). There is also some preliminary evidence that home ranges of bears from the east Greenland subpopulation overlap with those of bears from Svalbard in Fram Strait.