Polar bear sea ice habitat highs and lows in early February

Reposted from Polar Bear Science

Posted on February 10, 2021 | 

Sea ice across the Arctic in the first week of February is a mix of highs and lows. Bering Sea is back up to almost normal coverage, as is the Barents Sea. However, ice coverage on the East Coast of Canada is the lowest its been in four decades. This is not yet a worry for polar bears because harp seals don’t pup until mid-March in this region so there is at least four weeks of potential ice growth that can happen before the seals are forced to pup on much reduced ice – where polar bears are sure to find them.

Here is a close-up look at sea ice conditions by region at the edges of the Arctic.

BERING SEA

All of the ice coloured brown in the chart below from the Alaska Sea Ice Program for 10 February is multi-year ice while the yellow and green is first year ice:

Bering Sea ice at the end of January was well below average in 2018 but was close to normal levels in 2021, as it was in 2020 (see below):

Few polar bears venture into the Bering Sea on their hunt for seals, which means low ice over the Bering Sea in winter and spring is not the end of the world for the bears. The Chukchi Sea, north of the Bering Strait, is their primary habitat.

BARENTS SEA

After low ice coverage since mid-summer, ice coverage is back up in early February (above), with more ice off the west coast of Novaya Zemlya than there’s been in years and Svalbard ice is back up to almost ‘normal’ levels (below):

You’ll see from the graph below from the Norwegian Ice Service that sea ice is back up to where it was in 2020 and much higher than it was in 2012.

As a consequence, it’s not surprising that ice has again reached Bear Island (Bjørnøya) to the south of Svalbard (below) although earlier than it did in 2020 (yellow line in graph above): ice reached the island a few days before 8 March when a polar bear was spotted by the crew of the Meteorological Station:

CANADIAN EAST COAST

All the red in the chart below is ‘much less’ ice than usual in the Gulf of St. Lawrence and off Labrador and Newfoundland:

For the first week in February, this is the lowest that ‘East Coast’ ice has been since 1981. In a future post, I’ll address the issue of whether or not harp seal pupping (which occurs about mid-March) is likely to be impacted by such low ice levels.

Here is a closeup from the Canadian Ice Service showing the pitiful amount of ice present for the week of 8 February 2021 over the East Coast:

For comparison to the above, below are the same charts for 2018 (a fairly heavy ice year), same week (light green is thin first year ice, 30-70 cm thick):

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February 12, 2021 at 12:51AM

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