ANCHORAGE (AP) -- Beluga whales appear to be hanging around Cook Inlet this winter, but scientists tracking the mammals don't know what they eat.
Winter is desolate in upper Cook Inlet. It's a body of water dominated by silt-blackened ice floes. It's a place so harsh that virtually all marine animals, including the region's depleted beluga whales, were thought to migrate south to unknown seas to survive until spring.
Finding the mysterious winter destination of local belugas has become a critical task for federal biologists managing their recovery.
It remains an issue in a lawsuit filed by Native hunters and environmentalists: How can the genetically isolated whales that spend summers in northern Cook Inlet be fully protected until humans know where they go during winter?
The answer may have been swimming offshore all along.
Two beluga whales tracked by satellite have spent the past four months touring the frigid ocean near Anchorage's coast, undercutting conventional wisdom about how and where local whales survive winter.
Assuming the whales have been foraging for food at least some of the time, their movements suggest Cook Inlet might not be as desolate this time of year as it looks, several biologists said.
''The conventional wisdom is that there isn't much in the upper Inlet in the winter because it's such an inhospitable environment,'' said Lance Trasky, regional supervisor for habitat and restoration for the Alaska Department of Fish and Game.
But ''there might some marine fishes that come up in the winter, particularly when the salinity comes up. ... We never cease to be surprised.''
After they were captured in Knik Arm last September by federal biologists and released with satellite transmitters bolted to their dorsal ridges, the two whales basically continued their summer itinerary long after snow fell and salmon runs dwindled.
Before now, the only other beluga ever successfully tagged in Cook Inlet was tracked during summer.
An adult male named Ringo spent weeks cruising Turnagain Arm and Chickaloon Bay and was swimming north of Nikiski off the Kenai Peninsula when his tag stopped transmitting Jan. 3.
The second tagged whale, an adolescent female named Paulette, spent much of her time roaming the basin southwest of Fire Island at the head of the Inlet, moving from river mouth to river mouth.
She was swimming south toward Kalgin Island when her transmitter stopped on Jan. 16.
''She's been down there once before,'' said biologist Rod Hobbs, of the National Marine Mammal Laboratory in Seattle. ''We're assuming it was just one more of those excursions.''
Both whales made return trips up Knik Arm too, passing Anchorage several times. They were in Eagle Bay, near the mouth of Eagle River, on Nov. 6. Ringo returned once as late as Dec. 29.
What were they doing up there? And what, if anything, were they eating?
''I'm clueless,'' said beluga management biologist Barbara Mahoney.
''We don't really know what's keeping them up there,'' Hobbs told the Anchorage Daily News.
The tracking data, posted in 15 maps on the Internet by the Seattle-based lab, raises a host of other questions, too, Mahoney said.
Were these whales behaving normally, or did they remain north because the Inlet has much less ice this year than usual? Or do they maneuver among ice floes every winter? And how many other whales have stayed with them?
National Marine Fisheries Service biologists have conducted a few aerial surveys and seen only small groups of whales near the satellite fixes.
''The problem is they don't seem to be in those big groups, like they are in the summer,'' Hobbs said. ''If they're in those areas with a lot of ice, then you don't see them at all.''
Local Native leaders representing whale hunters in the region say they're not sure what to make of the findings, either.
''I think that it's kind of strange that they're here,'' said Jon James, president of the Cook Inlet Marine Mammal Council. ''I'm not sure how to explain it.''
''Very amazing,'' added Lee Stephan, the chief executive officer of the Native Village of Eklutna and the former president of the council. ''We thought they would just leave. ... It's quite surprising. If they're staying here, what are they eating?''
Once thought to number more than 1,300, the Cook Inlet beluga population has plummeted since the 1980s, with estimates ranging from about 350 to 435 whales during the past three seasons.
Federal biologist blamed the decline on subsistence harvests by Native hunters, while Natives and environmental groups have argued other factors must have played a role.
Last spring, the whales were listed as depleted under the federal Marine Mammal Protection Act and environmental groups sued to have the whales protected under the more stringent Endangered Species Act.
An element of proposed recovery schemes and harvest rules has been figuring out where the whales spend winter.
Next season, federal biologists hope to capture at least four belugas and equip them with more satellite tracking tags, Hobbs said. The agency also wants to begin surveying the upper Inlet waters for forage fish to find out what belugas might be eating.
Scientists were surprised when studies conducted for oil companies turned up lots of juvenile salmon summering in waters off the big Susitna River, said Linda Brannian, who oversees the state management of commercial fishing in the upper Inlet.
''What we're learning more and more is that some creatures do stay here year-around,'' she said.
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