At Howard Prairie reservoir in Southern Oregon, there once was a robust rainbow trout fishery.
“They grew really well and the trout fishery absolutely thrived,” said District Fish Biologist Dan Van Dyke, about the 350,000 rainbow trout released into the reservoir each spring.
Then, about 2005, fishing in the reservoir, located just 18 miles east of Ashland, crashed.
The culprit was the illegal introduction of a surprisingly large list of invader fish: golden shiners, brown bullhead, black crappie, and both largemouth and smallmouth bass.
It’s a story that’s been repeated throughout Oregon for decades, when carefully managed fisheries of native or stocked fish are greatly damaged because of illegal introductions.
In these cases, individuals dump leftover live bait, possibly not realizing the harm. Others purposely add a different breed of fish in an attempt to alter the fishing grounds. Some also abandon fish and other sea life from a home aquarium or school project.