Beluga whales frequent Knik River

MAT-SU -- Commuters crossing the Knik River bridge recently might be rubbing their eyes in disbelief, but it's true -- those are beluga whales in the water.

There have been several sightings of the marine mammals in the Knik River during the past week, and one man reported seeing a group of 10 or so traveling together. While this may come as a surprise to motorists, Alaska Department of Fish and Game biologist Dave Rutz said it isn't all that unusual.

"I got two calls this year because the guy thought he was going nuts," Rutz said from his Palmer office.

The fishery biologist says he has often seen whales in the Knik River, especially during high tides in the autumn. He believes belugas are coming in to feed on the salmon carcasses that are drifting down from Jim Creek and other streams this time of year.

"You see the same thing in the Susitna River," Rutz said. "I've seen them as far up as the confluence of the Yentna and Susitna."

According to Fish and Game's "Wildlife Notebook" on its Web site, belugas feed on a variety of fish, including salmon, herring and smelt. It is not unusual for belugas to ascend large rivers, and they do not seem to be affected by the change in the amount of salt in the water, according to Fish and Game. In 1982, a group of whales was spotted at Tanana, 750 miles from the river's mouth. In 1993, four belugas were seen near Fort Yukon.

The Knik River bridge is a relatively short distance from the saltwater of Knik Arm, and Rutz said throughout the summer belugas can be seen in Knik Arm near the Birchwood airport.

While the change from saltwater to fresh doesn't seem to be particularly threatening to the whales, Rutz said there is some danger of the large animals becoming stranded when the tide goes out. Adult males can weigh close to a ton and reach lengths of 15 feet.

"There can be big problems," Rutz said. But while beachings have occurred in Turnagain Arm, Rutz said the whales for some reason have not encountered such problems in the Knik River.

Belugas are the only kind of whale Rutz has seen or heard of in the Knik River, but they are not the only marine animals to follow the salmon into the streams of the Mat-Su Valley. Seals have also been spotted in fresh water in the area, including in the Big Susitna River and its tributaries, Rutz said. And perhaps even more than whales, the seals seem unaffected by the change from salt to fresh water.