ANCHORAGE, Alaska - The beluga whales swimming off Alaska's largest city are at considerable risk of going extinct unless something changes, a federal study says.
The study by the National Marine Mammal Laboratory in Seattle says if the Cook Inlet belugas go extinct, another group of the white whales probably won't come in to swim the silty waters off Anchorage.
"The population is discrete and unique with respect to the species, and if it should fail to survive, it is highly unlikely that Cook Inlet would be repopulated with belugas," the study says.
The study found there is a 26 percent chance the Cook Inlet belugas will be extinct in 100 years and a 68 percent chance they'll be gone in 300 years.
To make matters worse, it finds that the whales are becoming increasingly vulnerable to a catastrophic event because they are tending to gather in a restricted area in the upper Cook Inlet.
"At reduced numbers and with contraction of their range, this population is far more vulnerable to stranding, predation or disease," the report says.
Alaska has five distinct geographic populations of beluga whales. Apart from about 300 Cook Inlet belugas, other groups are doing well with a total population estimate of between 35,000 and 40,000 animals. The others swim the western Alaska coastal waters of Bristol Bay, the eastern Bering Sea and the eastern Chukchi Sea; others are located in the Beaufort Sea, north of Alaska and Canada.
The report is disheartening in light of efforts made in recent years to save the belugas. One of the problems is that scientists still do not know why numbers are declining.
It was thought that subsistence hunting, where about 70 whales were killed each year, was to blame. However, severe restrictions on subsistence hunting in place since 1999 have failed to turn the situation around.
"We thought it was entirely the result of the subsistence harvest but the subsistence harvest may have been masking another problem," said Rod Hobb, a biologist who helped prepare the extinction assessment.
New population numbers released Monday show a slight increase, but do little to change the overall picture, he said Tuesday.
"The overall trend is downwards," Hobb said.
There are now an estimated 302 beluga whales in Cook Inlet, slightly higher than the 2005 estimate of 278 animals, according to annual surveys conducted by NOAA Fisheries Service biologists.
The numbers are well below an average of 370 whales.
"If you step back to look at the big picture, the annual estimates from 1994 to 2006 show an average decline of 5.6 percent per year," said Doug DeMaster, administrator of the Alaska Fisheries Science Center.
The Cook Inlet beluga population declined by more than half between 1994 and 1999. The population was declared depleted in 2000 under the Marine Mammal Protection Act.
Now, the National Marine Fisheries Service is looking at whether the whales deserve increased protection under the federal Endangered Species Act. A recommendation is expected by April.
Hobb said 2,000 or more belugas likely swam the Cook Inlet but numbers had dropped to about 1,300 by the 1970s.
In 1994, the first year that the Alaska Department of Fish and Game conducted a complete survey of Cook Inlet, it found 653 belugas. The annual survey has trended downward since, reaching a low of 278 whales in 2005. The 2006 survey shows the slight increase.
"They have this downward trend and we don't know why that is," Hobb said.
