The Davis Strait - DCE - Nationalt Center for Miljø og Energi

Numbers: The status of the walrus subpopulation in Greenland and the eastern
Canadian Arctic was evaluated by the North Atlantic Marine Mammal
Commission in 2009 (NAMMCO 2009). The 2006 and 2008 aerial surveys
that were dedicated to estimating the abundance of walruses on their Central
West Greenland wintering grounds resulted in weighted averages of fully
corrected estimates of abundance. The estimate of abundance for the
southern wintering ground (i.e. between approx. 65° 30' N and 68° 15' N and
between the Greenland coast and approx. 56° W) was approx. 2,400 in 2006
and approx. 2,900 walruses in 2008 (Table 5 in Heide-Jørgensen et al. 2010a).
In 2005, 2006, 2007 and 2008 aerial surveys were conducted jointly by Department
of Fisheries (DFO, Canada) and the Greenland Institute of Natural
Resources (GINR, Greenland) during the ‘open water’ or ice free season over
the walrus summering grounds along Southeast Baffin Island between 62°
10' N and 69° 37' N. In 2007, a boat survey was conducted by DFO, GINR
and NERI along the coast of Southeast Baffin Island where walruses from
the West Greenland-Southeast Baffin Island stock haul out on land during
summer. The purpose was to arrive at an estimate of ‘minimum number of
walruses alive’ in these areas. The highest number recorded was 1,056 walruses
obtained on 3-4 September 2007 (NAMMCO 2009). This number has
not been adjusted for animals at sea and not present on or at the haul-outs
during the survey. Studies of walrus behaviour in other parts of the Arctic
indicate that walruses spend an average of approx. 25% to approx. 40% of
their time on land (cf. Born 2005). This indicates that several thousand walruses
from the West Greenland-Southeast Baffin Island stock can be found
during summer along southeastern Baffin Island.
Movements: Scattered observations offshore in Davis Strait in March–July
suggest that walruses migrate across Davis Strait from western Greenland to
eastern Baffin Island during spring (Fig. 4.8.2) (Born et al. 1982, Born et al.
1994). Satellite telemetry during spring of 2005–2008 supports the notion that
the majority of walruses that winter in Central West Greenland move west
to summer at southeastern Baffin Island (NAMMCO 2009, Dietz et al. 2010).
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