JACKI LYDEN, host:
Most of the world's walrus spend the winters in the Bering Sea between Alaska and Russia. They depend on the ice flows(ph) that cover the sea as their home, breeding ground and feeding area. But that home is disappearing rapidly. Scientists predict that in less than 50 years the ice will have vanished. And with the loss of the ice, walrus numbers are expected to decline.
Alaska Public Radio Network's Annie Feidt reports that a massive high-tech effort is underway, to count just how many walrus there are now, so that changes in the population can be tracked in the future.
ANNIE FEIDT reporting:
Biologists used to count walrus the old-fashioned way: with their eyes. They used low-flying planes to scan the sea ice for the animals. But the estimates had huge margins of error. The last count in 1990 found 200,000 walrus, plus or minus 100,000. This time around, biologists are still using a plane. But instead of staring out the window, they stare at a computer monitor that displays images from a thermal scanner. At an Anchorage airplane hangar recently, a mechanic installed the scanner under the tail of the small plane.
(Soundbite of hammering)
FEIDT: Biologist Doug Burns(ph) says the scanner is designed to move back and forth across the ocean like a lawnmower.
Mr. DOUG BURNS (Biologist Tracking Sea Walrus): Basically, we fly the airplane out over the Bering Sea. The walrus is sitting on top of the ice. The ice is very cold. The water that the walrus swim in is also very cold. But the walrus' skin themselves is actually quite warm and they actually show up like little glowing coals.
FEIDT: Once biologists know how many walrus are on the sea ice, they'll use satellite tags to find out how many more are probably lurking under the water. They deployed the tags last month with specially designed crossbows.
Mr. TONY FISCHBACH (Wildlife Biologist Tracking Sea Walrus): This is our mock walrus.
FEIDT: Before setting out on the Bering Sea, biologist Tony Fischbach practiced his aim.
Mr. FISCHBACH: Have your target in sights and...
(Soundbite of satellite tag fired)
Mr. FISCHBACH: ...there it goes.
FEIDT: On this day, Fischbach is wearing a dress shirt and khakis. But out on the sea ice, he wore a white gown to blend in as he approached walrus. He says he was trying to look like a slowly moving snow bank.
Mr. FISCHBACH: Sometimes it would take hours where you're crawling on your belly to get across this flat area where the walrus could clearly see you, so you have to move really slowly. You're all dressed in white. You've left your backpack behind so they won't see that. But as you're doing that, you've gotta, you know, make sure you're dancing around the active ice, so that you're not -- nobody's falling in.
FEIDT: Fischbach's team cruise the area in an icebreaker, a type of ship that could be unnecessary in the Bering Sea in a matter of decades.
Gary Hufford is a scientist with the National Weather Service in Alaska. He says that's because the ice is retreating at an incredible pace.
Mr. GARY HUFFORD (Scientist, National Weather Service): Now that's pretty scary, because we have an environment that's gonna really change with the lack of ice. We're seeing water temperatures increasing at rates like we've never seen before. The environment's not able to adjust as it would if you've got change occurring over thousands of years instead of here, changing over decades. And that's an area in which we don't have a lot of scientific expertise in.
FEIDT: When the ice does disappear, walrus will face a very different existence. University of Alaska Wildlife Biologist Brendan Kelley doesn't think walrus will become extinct, but he says the population will suffer.
Mr. BRENDAN KELLEY (Wildlife Biologist, University of Alaska): If you have an oil spill and you have lots of dead animals floating around, it's fairly dramatic and distinctive. But if you have degrading habitat, which is what we have with this reduction in sea ice, it may not be killing walruses outright, but it may be causing them to have to spend a lot more energy to get their food and nurse their calves. And the net effect of that will be fewer walruses born, fewer making it through their juvenile stages.
FEIDT: As the population declines, scientists are concerned the entire ocean ecosystem could suffer too. That's because walrus are like earthworms in the water, churning up massive amounts of nutrients that keep the ocean healthy.
For NPR News, I'm Annie Feidt in Anchorage. Transcript provided by NPR, Copyright NPR.