September 17, 2012
Climate Change Shrinking Sea Ice, Seal Species Threatened
Lee Rannals for redOrbit.com — Your Universe Online
The ringed seal uses ice to build caves for its young, which need at least 8-inches of snow drifts on sea ice in order to be supported. Without sea ice, the platform that allows the snow to pile up disappears, reducing the area where seals can raise their pups.
The researchers were responding to a government need to evaluate whether climate change was causing the ringed seals to be considered for protection.
The Center for Biological Diversity is suing the agency in an attempt to try and compel it to go ahead and grant the seals threatened status.
The National Marine Fisheries Services agreed to a proposal in 2010 that justifies Endangered Species Act protection for the seals due to Arctic climate change. A spokeswoman for the National Oceanic and Atmospheric Administration (NOAA), the parent agency, said the seal listings were still underway.
Now, researchers following up on the matter found that snowfall patterns will change during this century, which could negatively affect the seals trying to build caves. However, they said the biggest threat was the disappearance of the sea ice.
Sea ice is expected to start forming later in the year than it does now, and the slightly heavier snowfall in the winter will not compensate for the fact that in the fall, snow will drop into the ocean instead of pilling up on the ice.
The team is anticipating that the area of the Arctic that accumulates at least 8-inches of snow will decrease by nearly 70 percent this century. Without this accumulation, and the ice surface beneath it to hold it, the seals will have no caves for their young.
Snow and ice not aligning up isn't the only concern for the seals. Scientists also worry the snow caves will not last until the young seals are old enough to venture out on their own. Also, more precipitation will fall as rain in the upcoming century, causing some caves to collapse.
To come to these conclusions, the scientists first examined 10 different climate models, looking at historic and future changes of things like sea ice area, precipitation, snowfall and snow depth on sea ice.
The research comes too late to be cited in the report about ringed seals that was written up by the NOAA in response to the lawsuit. However, it confirms results that were based on a single model that was provided for the agency two years ago.
The government agency expects to issue its final decision on the ringed seals' threatened status soon.