ANCHORAGE - The white whales of Cook Inlet that have delighted locals and tourists for decades are slowly disappearing and perhaps headed toward extinction.
With fewer than 300 beluga whales swimming in the silty waters of near Anchorage, one cataclysmic event - a large stranding in the inlet's 20-foot tides, perhaps, or an oil spill or tsunami - could push them over the edge, said Lloyd Lowry, a professor of marine mammals with the University of Alaska Fairbanks.
"Having a small population for a long time is very risky," said Lowry, former marine mammal coordinator with the Alaska Department of Fish and Game. "If the decline continues we are going to get to very critically low numbers soon."
The National Marine Fisheries Service is embarking on a status review to determine if the belugas need the protection of the federal Endangered Species Act. A listing was rejected in 2000 because then it was believed overharvesting was to blame.
Seven years of strict limits on hunting have proved that theory wrong, Lowry said Monday.
"There is something else going on," he said.
Brad Smith, a biologist with the National Marine Fisheries Service, said the status review will be expanded this time. It will include a prediction at what point the whales - considered a genetically distinct population - could go extinct. The last review was done about a decade ago.
Data on the whales shows the decline.
"It certainly does not look encouraging," Smith said.
There used to be about 1,300 belugas in Cook Inlet in the 1970s. Last year the number was estimated at 278. The goal is to restore numbers to about 800.
NMFS recently set a harvest limit of eight whales through 2009, alternating a harvest of one and two whales a year. The harvest amounts to an overall increase of two in the previous five years.
Only Alaska Native subsistence hunters are allowed to kill the whales. Before the restrictions were put in place in 1999, the subsistence harvest averaged about 70 whales a year.
The harvest now is set so low that the population should be growing 2 percent to 4 percent a year, but it's not, Lowry said.
"This population, according to pretty good survey data, is not growing at all," he said.
The status review will look at possible reasons for the decline. That includes changes in habitat, such as noise from shipping, recreational boating and pile driving. The noise could be interfering with the whales' ability to locate each other and find food, Smith said.
Scientists also will look at development around the inlet, including the expansion of the Port of Anchorage. Waste discharges from the municipality will be considered, as well as the impact of oil and gas development.
"There are a lot of things we are looking at," Smith said. But so far, he said, nothing jumps out as a likely cause.
"There is no smoking gun," he said.
An endangered species listing would require that critical habitat be designated for the whales. That means that federal agencies needing a permit would have to go through a process to make sure their projects would not harm the whales. Those projects likely would include most shoreline development, municipal waste discharges, the Corps of Engineers and the Port of Anchorage.