Shrinking sea ice is wreaking havoc on Arctic ringed seals (Phoca hispida hispida), which live throughout the Bering, Chukchi, and Beaufort seas. The seals live in and beneath the ice and even birth and nurse atop it. Now, the National Oceanic and Atmospheric Administration (NOAA) has proposed designating a vast areamore than 906,000 square kilometersoff Alaska as protected habitat for the seals. The pinnipeds, which are named for the lacy, white circles on their fur, were listed as threatened under the Endangered Species Act in December 2012.

At the Center for Biological Diversity in Tucson, Arizona, which had petitioned NOAA to address the seals’ plight, conservationists reacted with joy to the proposal. The organization’s climate science director, Shaye Wolf, said in a statement: “We’re thrilled that the ringed seals are getting the habitat protections they so desperately need as their sea-ice home melts beneath them. But Senator Lisa Murkowski (R–AK) criticized the proposal. “This is an unprecedented attempt to place restrictions on a larger than Texas-sized area of water surrounding our state, she said in a statement.

NOAA’s proposal stems from a yearlong study of the critical habitat needs of the seals and the economic effects that protecting them may have on the region, which harbors extensive oil and gas reserves and commercially valuable fish.

NOAA’s scientists identified climate change as “the principal threat to the animals. The seals rarely come ashore, but live instead beneath the ice, using their claws to open and maintain breathing holes. They also construct caves on top of the ice and under the snow, where they birth and nurse their young. They build several of these caves so that they always have a place to escape their chief predator, polar bears.

Climate change models predict that the Arctic sea ice will continue to shrink in a warming world (as much as 40% of the ice is expected to be gone by midcentury), and the resulting changesincluding later formation of ice in the autumn, rain falling on the snow, and decreasing snow depthswill make it increasingly difficult for the seals to construct their snow caves, NOAA says. And that, in turn, will likely lead to a significant decline in the seals’ population, which was thought to number about 2.5 million in 2002. Since then, researchers have recorded a decreased number of pups in some areas, probably because of climate change. A pup often dies when its cave collapses on top of it. If a species is likely to become endangered in the future throughout a major portion of its range, it is considered threatened.

If the proposed critical habitat designation is approved, other federal agencies will be required to consult with NOAA Fisheries on actions such as oil exploration and drilling that could destroy or adversely affect the area. The designation is also likely to impact commercial fishing in the region. Because the dwindling ice is lengthening the open-water commercial fishing season, certain target species (such as Arctic cod and saffron cod, which are the seals’ preferred prey) may also require “special management considerations, NOAA says. The proposed designation would not, however, stop the subsistence hunt of the seals by Alaska natives.

Although most oil and gas activities are now occurring only in the Beaufort Sea, primarily near Prudhoe Bay, there has been a recent lease sale in the Chukchi Sea, NOAA notes, and the agency expects oil exploration and drilling to increase there. Murkowski worries about the economic effects of the proposal and charges in her statement that NOAA’s decision was motivated by “several non-scientific reasons, such as “enhanced public awareness. She also expresses concern that the designation “may help focus and contribute to conservation efforts. “I remain skeptical, her statement says, “that the listing of ringed seals based on a 100 year weather projection was justified, and I am concerned that this designation would severely impact any economic development from Northwest all the way to our border with Canada.

NOAA will be accepting public comments on the proposed critical habitat designation for the ringed seals for 90 days, until 3 March 2015.

2014 American Association for the Advancement of Science