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Thick multiyear ice between Wrangel Island and the shore is now more than 2m thick, potentially impacting fall feeding for bears that routinely summer on Wrangel or the north coast of Chukotka.

Rapidly-forming sea ice in the Laptev and East Siberian Seas this fall – generated by cold winds from Siberia in late October despite warmer than ususal temperatures earlier in the month – has trapped a number of Russian ships that are being rescued by ice-breakers (below), according to a report in the Barents Observer earlier this week.

As I mentioned last month, much of the ice along the Russian coast of the Chukchi Sea adjacent to Wrangel Island (see map above) where Pacific walrus have hauled out in recent years remained covered in ice all summer and thus unavailable to walrus. By the middle of October, as new ice began to form in the area, that ice officially became ‘multiyear’ ice.

Progression of Sea Ice Conditions

See conditions at mid-October (18th), showing walrus haulouts (where polar bears congregate to feed on carcasses):

Below are conditions one month later (17 November):

The area both north and south of Wrangel Island is critical to ships using the Northern Sea Route to get from western Russian ports to those south of the Bering Sea but according to DMI was covered in ice 2-3.5m thick by 17 November (below).

That’s why ice-breakers have had to rescue transport ships caught in the ice. But it also will have had an impact on polar bears in the region who will have had to move onto thinner ice forming towards the Bering Strait in order not to have their important fall feeding period cut short.

Mixed walrus herds of cows and calves will already be in the northern Bering Sea waiting for adult males to join them. In the fall, males leave their summer haulout beaches in the southern Bering Sea to meet the mixed herds massing to the north. Mating takes place in the water in December/January, which is why walrus need mobile pack ice with access to open water in winter.

via polarbearscience

November 18, 2021