Banging together steel pipes might be one way biologists can herd three possibly stressed killer whales out of the Nushagak River and back into their normal habitat in Bristol Bay, said a spokeswoman with the National Oceanic and Atmospheric Administration.
The whales have been lingering for three weeks some 30 miles up the Southwest Alaska river, an apparently unprecedented event, and biologists worry they may become sick because they're not in their normal environment, said NOAA spokeswoman Julie Speegle.
"I guess this is the first time in Alaska that killer whales have been seen this far upstream in fresh water," she said.
Oikami, or pipe-banging, has apparently been used to herd whales before. If the whales don't move on their own, biologists are considering boarding boats in the area south of Ekwok and effectively creating an uncomfortable wall of sound that drives the whales toward saltwater.
The agency is moniting the situation with first-hand reports from people in the area and doesn't have scientists on scene. That could change if the animals continue to loiter.
"We're going to give them a bit more time to move downstream before we take any action," maybe next week, Speegle said.
In case they don't, NOAA marine biologists are putting together a team that includes the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service to come up with a plan that might include oikami or other methods to "encourage the whales" along, Speegle said.
It's not known why the Orcas entered the river and kept going, though such behavior isn't unusual for other whales, such as beluga whales that have been seen well upriver in many areas.
Perhaps they were chasing prey, Speegle said.
Scientists don't know why the whales are hanging around, or how long they have before the river begins to freeze or fall enough to endanger them. They also don't know if the whales have been feeding or not. They were last spotted on Tuesday near a fork in the river north of Dillingham, she said.
Officials are warning the public to keep away from the whales.