The northern pikeminnow have been preying on salmon and steelhead juveniles in the Eel river watershed since 1979, when the non native fish was first introduced, likely by fishermen using them for bass bait.
The Eel River Recovery Project surveyed pike minnow populations in the river in 2016 and released their results in February 2017. Pat Higgins, director of the Eel River Recovery Project has the details in part 1 of the Pikeminnow Invasion.