Bad News for Ice Seals: Arctic Winter Sea Ice Hits Record-Breaking Low
It’s official: Arctic sea ice hit a historic low this winter. It’s the latest sign of a long-term, perhaps permanent shift in historic climate conditions and could affect the region’s ice-dependent marine mammals.
Now that spring weather is developing, the ice is starting to melt back. It’s not possible to guess how much the ice will decrease toward its summer minimum based on its winter maximum. But a recent study found that in addition to decreasing in area, Arctic sea ice has thinned 65 percent since 1975, from around 11 to four feet.
This year’s record-breaking low in winter sea ice could lead to a difficult summer for walruses and ice seals, said Raychelle Daniel, a marine mammal ecologist with the Pew Charitable Trusts in Alaska, as well as the Alaska Native communities that depend upon them for food. “Walruses travel north with the receding sea ice. They use the ice to give birth and rest, and as platform to go to the shallows to feed on clams and other organisms,” Daniel said.
“As the summer progresses, there’s concern the ice could recede faster and that the walruses won’t have adequate time to feed over the shallow continental shelf," she said, and "consume enough calories for themselves and their nursing calves.”
“If that happens they might haul out in greater numbers on land, and that poses some risks,” she said, because on land the animals are easily spooked into potentially deadly stampedes.
Ringed and bearded seals are also under stress as climate change transforms the Arctic, Daniel said. “With increasing temperatures and loss of sea ice, there’s concern about the habitat that’s so important for pupping and molting in the spring.”
Wildlife officials at the National Marine Fisheries Service are investigating what areas of the Arctic Ocean will be considered “critical habitat” for ringed seals to try and ensure the species’ survival as climate change continues to intensify. The public can comment on the agency’s proposals for critical habitat until March 31.
Floating polar ice covered 5.61 million square miles of the Arctic Ocean on February 25, according to information released today by the National Snow and Ice Data Center. That’s the lowest winter sea ice coverage since 1979, the year satellite data gathering began.
The three years in the satellite record with the least winter sea ice have all occurred in the past 10 years. The previous record of 5.65 million square miles occurred in 2006 and was roughly tied in 2011.
Between 1979 and 2000, winter sea ice coverage on the Arctic Ocean averaged 6.12 million square miles.
The NSIDC suggested that a variety of unusual weather patterns were partly to blame. Early March air temperatures above the eastern Arctic were 14 to 18 degrees Fahrenheit higher than average in some places, for instance, while some strange kinks in the jet stream warmed conditions over the Alaskan and Russian Arctic.