Will Global Warming Doom the Pacific Walrus?

from Wildlife Promise

I was a little boy when I checked a book called The Son of the Walrus King out of the local public library and fell so in love with its story of a young Pacific walrus’s Arctic travels with his mother that I couldn’t bring myself to return the book until I had run up a hefty fine.  The tale was full of adventures with Inuit hunters and polar bears and dangerous seas.  The story made me want to head for the Far North and see these massive animals for myself (this was only shortly after the period in which Rudyard Kipling’s Mowgli stories—about a boy raised by wolves in India—had made me determine to run off to Asia and live with wolves).  My imagination was invigorated by that walrus story, but not enough to conjure up what would happen to Pacific walruses within the next few decades.

Walrus by Mark Carwardine

A walrus in the Canadian Arctic's Foxe Basin is at home on the ice.

I am talking, of course, about global warming, a term that was not part of the common parlance when I was a child, though the phenomenon was already a concern for many scientists.  As the Earth has warmed in the wake of increasing greenhouse-gas pollution of the atmosphere, Arctic ice—critical to walrus survival—has been melting.  Any young child today who became inspired by a book about walruses might just live to see the last walrus sink, literally, into extinction.

What’s So Great About the Pacific Walrus?

Well, its size for one thing.  Pacific walrus males, or bulls, average about 2,700 pounds and measure 10.5 feet long, making them one of the largest pinnipeds—a term meaning “fin foot” that refers to seals and sea lions as well as to walruses, dugongs, manatees and their relatives.

Walrus by Peter Hemming

A walrus at Foxe Basin in the Arctic Ocean clings to an ice floe too small to support its weight.

The Pacific walrus is the largest of three surviving walrus subspecies. The Atlantic  walrus, found more in the eastern end of the Arctic Ocean, is the smallest, and the Laptev walrus, of Russia’s Laptev Sea, is middle sized.   The walrus is the only pinniped armed with long, curved, ivory tusks, which can weigh up to 3 pounds each.  Here are some Pacific walrus facts that should impress an adult and wow a child:

  • When born, walruses weigh 100 to 150 pounds and are more than 4 feet long.
  • Bulls aren’t fully grown until about 15 years old; females mature at 10, topping out at about 1,900 pounds and 9 feet long.
  • Walrus blubber can grow up to 5 inches thick, insulating the animals from sub-freezing Arctic sea water.
  • Migrating Pacific walruses travel up to 1,800 miles.
  • Walruses eat sea cucumbers, sea worms and other marine animals, but their main food is clams, which they eat on the ocean floor.
  • Walrus numbers were much reduced by years of uncontrolled hunting in the 19th and early 20th centuries, but thanks to protection by laws such as the Marine Mammal Protection Act, the Pacific walrus seems to be recovering—it numbers about 200,000 animals (the Atlantic, much harder hit by hunting, languishes at only about 20,000, and the Laptev Sea walrus numbers about 10,000).

The Global Warming and the Pacific Walrus

Unlike the Atlantic walrus, which tends to stay close to shore, the Pacific walrus typically summers on ice in the Chukchi Sea, floating over the continental shelf.  Shelf waters are shallow enough—less than 630 feet—to allow the animals to dive for food.  But in recent years the ice has been retreating toward the pole, thanks to global warming.  According to the Intergovernmental Panel on Climate Change, Arctic temperatures have risen during the past century by 1.1 to 1.6 degrees °F.  The panel predicts that the Arctic could warm by 5 to 14 degrees F by the end of the century, and that sea ice could disappear in summer within the next 40 years.

Walrus group by Larry Wan

Walruses group up in tight quarters at the Arctic's Round Island.

As the sea ice retreats in summer, it takes walruses far from shore and away from the shallow waters they need for feeding.  To stay near the continental shelf, the animals have been seeking resting places on land rather than on ice.  Unfortunately, whereas the sea ice was widely scattered and allowed walruses to disperse throughout feeding areas, the beaches, limited in number and often in size, tend to concentrate the animals within restricted feeding areas, increasing competition for food.

In some areas thousands of walruses are cramming on to beaches that can hold only a fraction of their numbers, with these terrible results:

  • Young and small walruses are being crushed.  On Alaska’s Icy Cape scientists in 2009 found 131 dead calves that apparently had been crushed.  Biologists also found thousands of crushed walruses near Russia’s Cape Schmidt in 2007, where tens of thousands had packed ashore.
  • Thousands of young walruses also probably drown in open waters when they cannot find ice for resting, but accounting for such animals is difficult if not impossible.
  • Stress on walruses increases as more of the animals crowd into feeding areas near shore, jeopardizing their nutritional health and reducing the number of young that are born or survive.

The U.S. Fish and Wildlife Service, which is studying whether the walrus should go on the endangered species list, has warned that as ice in the Chukchi disappears, there is a 40 percent chance that the walrus will be extinct or in danger of extinction by the end of this century.  Ominously, the state of Alaska is working to open the Chukchi Sea to oil drilling and opposing the listing of Arctic pinnipeds dependent on ice (the state is trying to have the polar bear, also jeopardized by loss of sea ice, taken off the endangered list, too).

What’s the Future for the Walrus?

One hope for the walrus is that it will be listed as an endangered species, which will give it protections designed specifically to spur its recovery.  However, recovery plans for marine species are difficult to initiate.  The problem is compounded because the greatest threat to walrus survival, as well as to the survival of many other Arctic species, is global warming.  If climate change is not abated, then measures taken to protect the walrus will likely fail, leaving the animal to survive only in books.  Global warming is so dangerous on so large a scale that its threat extends well beyond the Arctic.  “The science is clear, that unless we act now we will likely see 20 to 30 percent of all plant and animals species extinct or on the road to extinction by 2050,” says Larry Schweiger, NWF president.

NWF and Global Warming

Combating a warming climate is an NWF priority.  Aside from working to pass federal laws designed to reduce greenhouse gases, NWF offers you many ways to help fight global warming and ensure a future for wildlife and habitat.