On Thin Ice
U.Va. researchers warn of what global warming could mean to animals.
Posted May 14, 2008, 12:19 PM EST
Photo by Tom Cogill
Copyright Richmond Times-Dispatch, used with permission.
The polar bear has become the furry face of climate change in the Arctic.
The bear is deserving, but other animals—particularly the walrus and a living sausage called the ribbon seal—are in even worse peril, a University of Virginia researcher says.
“Polar bears are very familiar to people,” said G. Carleton Ray, “but actually they are not as endangered as these seals and walruses.”
Ray, 79, has been studying animals in the Bering Sea region since the late 1950s. His wife and fellow marine ecologist, Jerry McCormick-Ray, 64, has been working there since the early 1980s. She concentrates on clams—the favorite dish of the walrus—and other small animals living on the sea floor.
Scientists say global warming is particularly apparent in the Arctic and sub-Arctic regions, where research indicates floes of sea ice are increasingly melting away.
Polar bears, walruses and ribbon seals use sea ice as platforms for reproducing and feeding. If the ice disappears, doesn’t remain long enough or becomes too thin, the animals’ numbers could drop drastically as the parents don’t adequately reproduce and abandoned youngsters starve.
Polar bears could potentially persist in much lower numbers on land, Ray said.
“The point is, these guys are totally dependent on the sea ice,” he said of the seals and walruses. “That’s it.”
The Rays’ research included a five-week trip to the Bering Sea last spring, supported by the National Science Foundation, aboard the 420-foot Coast Guard icebreaker Healy.
In the Bering Sea, between Alaska and Russia just south of the Arctic Circle, sea ice normally disappears in summer. But research has shown a “distinct trend” in ice loss from March through June, Ray said.
That’s when the seals and walruses are giving birth and nursing their young, Ray said. On his computer in his U.Va. office, Ray showed satellite images of the disappearing ice. “It is melting earlier by about three weeks, and it is forming later by about three weeks,” compared with the 1980s, Ray said.
Because polar bears and even walruses can live on land somewhat, Ray doesn’t believe they will become extinct. Ribbon seals, however, never go on land. Ray called their extinction a “distinct possibility” if warming trends continue.
Shaye Wolf, a biologist with the Center for Biological Diversity, a Tucson, Ariz.-based conservation group, said Ray is “very well-respected in the scientific community for his work” on walruses and seals.
The U.S. Fish and Wildlife Service is proposing to list the polar bear as threatened under the Endangered Species Act. A decision could come within a few weeks. Climate change, and the melting of sea ice, are the main reasons behind the proposal, said wildlife service spokesman Chris Tollefson.
Federal officials also are considering requests to protect the Pacific walrus and ribbon seal under the species act. A decision could be more than a year away.
Why care about polar bears, walruses and seals?
For one thing, people have an emotional attachment to them, Ray said.
Of the three, the public is least familiar with the ribbon seal, whose chocolate coat is marked with cream-colored bands. (Young ones are white.)
“They are the cutest darn animals you ever saw in your life,” Ray said, “and the idea of their habitat melting out under them and stranding those little baby seals would be a hot political issue.”
A severe decline in walruses and seals—Ray says some decline has probably occurred already—also would mean few animals for native Alaskans’ subsistence hunts.
There is also an ecological dimension.
Walruses root around on the sea floor for clams, worms and other food. That rooting appears to release nutrients that feed tiny plants, which in turn feed tiny animals such as shrimplike krill, which are eaten by whales, seals, fish and diving seabirds called auklets.
That chain reaction may contribute to making the Bering Sea, which to an outsider appears barren and hostile to life, a lush realm that rivals tropical rainforests in biological richness.
“It’s probably one of the most productive places on Earth,” said McCormick-Ray, also a U.Va. researcher.
The melting of sea ice could aid shipping, fishing, tourism and oil exploration. That would be good for commerce but probably disastrous, in terms of oil spills and pollution, for that little-understood ecosystem, the Rays said.
“Because it is a severe environment,” McCormick-Ray said, “when that severity is diminished, it opens up opportunities for people to do what they’ve done to the temperate areas, like what they’ve done to the Chesapeake Bay….
“I think it’s more sensible to not just rush in there like the gold rush and exploit it. Slow down until we know what’s going on. I’m not sure human appetites can do that. They see an opportunity, and they race in.”