Smallmouth bass
Brian Gratwicke/Flickr
The Oregon Department of Fish and Wildlife begins a process Monday that will poison fish in 10 different ponds around the state, so those ponds can be restocked with trout.
Species like brown bullhead catfish, smallmouth bass, black crappie and goldfish have been illegally introduced over years.
As they've multiplied, they've crowded the trout, said Jessica Sall, with Oregon Fish and Wildlife.
"And for many people, trout is the preferred fishery," she said. "These other fish out-compete trout for food and they can also affect water quality as they dig around in the bottom, looking for food and so can make it more difficult for the trout to survive."
Sall said that the EPA approved fish-toxicant called rotenone is mixed into the pond water, and that it is not harmful to humans, other mammals or birds.
Related: See how rotenone poisoning worked at Diamond Lake in this earlier story from Oregon Field Guide.
Bill Bakke with the Native Fish Society said he supports the plan.
"It’s time that the state takes action to start removing these animals from our waters," he said.
The ponds will be treated over the next few weeks. They are Luger, Boundary and Peach ponds in Union County; Keyhole, Granite Meadows, Goldfish, Yellowjacket and Windy Springs ponds in Umatilla County; Kinney Lake in Wallowa County; and Balm Reservoir in Baker County.
They’ll remain closed to the public for up to four weeks for detoxification.