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Fish & Aquatic

Cutthroat trout
Chris Schnepf, University of Idaho, bugwood.org
Cutthroat trout, a threathened native species

US Forest Service research on invasive aquatic organisms is mostly focused on non-native fish. Introduced fishes have caused major changes in abundance and distribution of native amphibians, zooplankton, and benthic invertebrates. These changes are likely to threaten species persistence, especially in the face of climate change. Forest Service scientists are studying the impacts of introduced fishes on invertebrates, amphibians, reptiles, birds, and bats. See, for example Nonnative Trout.


Sacramento pikeminnow
Carl Page
Sacramento pikeminnow, native & invasive

Sacramento pikeminnow are native to the Sacramento San Joaquin drainage but invasive in the Eel River. They prey on adult native salmonid fishes, and their young compete aggressively for food. Pacific Southwest Research Station scientists have found restoring cooler temperature to waters of the Eel River could help tilt the balance in favor of native fishes.