A survey of Alaska's Cook Inlet this summer found more beluga whales than last year, but government scientists say when the long view is taken numbers for the endangered animals continue to slide downward.
National Marine Fisheries Service scientists estimated Friday that there are 340 beluga whales in Cook Inlet. That's up from 321 last year. The number was arrived at from aerial surveys conducted in early June when the whales were gathered near the mouths of rivers to feed on fish.
Cook Inlet's beluga whales were listed as endangered in 2008. Scientists say the overall trend going back to 2001 shows about a 1 percent decline each year.
The Cook Inlet whales, which swim mainly off Anchorage, are considered a genetically distinct population and don't mix with the other four beluga groups in Alaska.
Rod Hobbs, leader of the beluga project at the National Marine Mammal Lab in Seattle, said not too much should be made of this year's increase because the Cook Inlet beluga numbers vary from year to year.
Looking at the long-term trend provides a better indication of what is actually happening to the belugas, he said. A healthy population of whales would be expected to grow at between 2 and 4 percent a year, Hobbs said, and that's not happening.
"We need a lot more research before we can actually narrow down the reason for why they are not increasing," he said.
While overharvesting by Alaska Natives was largely responsible for the initial decline, the whales have not recovered despite years of nearly no hunting.
There were about 1,300 Cook Inlet belugas in the 1980s but numbers had declined to an estimated 653 in 1994. Numbers reached an all-time low of 278 in 2005. Alaska's other four beluga groups are not endangered and number in the thousands.