Nez Perce Tribe
Department of Fisheries and Resources Management
Aquatic Invasive & Nuisance Species Program
Fish species such as Walleye, Smallmouth Bass, and Northern Pikeminnow, are known to be voracious predators and can feed heavily on juvenile salmonids as they migrate throughout the Columbia River Basin. Now that Walleye have successfully established themselves in the Lower Snake River Basin along side Smallmouth Bass and Northern Pikeminnow, there is a growing concern for the level of predation on juvenile salmonids as the three predatory fish inhabit the same space as spawning and rearing salmon, steelhead, and lamprey. The loss of these vital cultural resources will lead to dramatic implications for indigenous culture including treaty rights, availability and use of first foods, traditional place names, and language all of which are critical to the Niimiipuu's identity.
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Predatory Fish
Walleye
Sander vitreus
Species Information
Description:
Typical adult size is 14-20 inches, often appear green or brown with gold flecks, white under belly, and white spot on the lower tip of the tail. There are two distinct dorsal fins with one being spiny-rayed and the other soft-rayed with distinctively cloudy looking eyes.
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Impacts:
Walleye are voracious predators which notably feed primarily on salmonids and can account for about 1/3 of annual salmonid predation loss in the Columbia River. Walleye have been encountered at Lower Granite Dam on the Lower Snake River since 2016 and are now being caught on the Salmon River upstream as far as Riggins, ID. Walleye becoming established in the Lower Snake River Basin, which includes the Salmon and Clearwater Rivers, is a major threat to salmonid spawning and rearing.
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Native Range:
Walleye are native to the Great Lakes and Mississippi River Basins and can be found in lakes, reservoirs, rivers, and large slow moving streams.
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Walleye Distribution within NiMiiPuu U&A Homelands:
Ongoing reports of angler caught Walleye above Lower Granite Dam suggests that a population has become established within Nez Perce U&A homelands. Predatory fish management will target Walleye removal and population control.
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What to do if Encountered:
If caught, do not release back into the water alive, take a picture, and report your findings to the Nez Perce Tribe's Aquatic Invasive & Nuisance Species Program @...
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AINS Program Lead, Clark Watry at 208-621-3549
AINS Biologist, Anthony Capetillo at 208-621-3553
and/or contact Idaho Department of Fish & Game Biologist Marika Dobos at 208-750-4228.
Invasion Timeline
1940s
Late 1990s
2016
2024
Walleye are already present in the Columbia River Basin.
Walleye reach the Snake River.
Walleye begin to be detected at Lower Granite Dam on the Snake River indicating that they have reached vital Snake River Basin salmonid spawning and rearing habitat.
Idaho Fish & Game begin "Catch, Kill, Report" initiative which sparks reports of walleye being caught by anglers up the Salmon River as far as Riggins, Idaho, and on the Snake River up as far as the Hells Canyon Dam.
Smallmouth Bass
Micropterus dolomieu
Species Information
Description:
Typical adult size is 10-16 inches, generally a green or brown color with dark vertical bars on their sides and 13-15 rays on their dorsal fin.
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Impacts:
Smallmouth Bass are known to feed on juvenile salmonids with an estimated 860 thousand sub-yearlings being lost to predation by smallmouth between the upper Hells Canyon production areas and Lower Granite Dam each year. Smallmouth bass also threaten salmonid spawning and rearing habitat.
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Native Range:
Smallmouth Bass are native to east and central North America and can be found in lakes, reservoirs, rivers, ponds, and streams. Smallmouth Bass were introduced to the Snake River in the 1980s.
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Smallmouth Bass Distribution within NiMiiPuu U&A Homelands:
Smallmouth Bass are established within the U&A homelands of the Nez Perce. Tribal and state governments have begun discussions on predatory fish monitoring and removals which include addressing Smallmouth Bass in the Columbia River Basin.
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What to do if Encountered:
If caught or being used as fishing bait, do not release back into the water alive.
Invasion Timeline
1874
1924
1946
Smallmouth Bass are introduced to California for sport fishery opportunities.
Smallmouth Bass are first introduced to the Columbia River Basin in Oswego Lake, Portland (adjacent to the Willamette River). Stocking continued throughout the Pacific Northwest with Smallmouth Bass being introduced to the upper Willamette River in 1925.
Smallmouth Bass have become established in the lower Columbia River Basin which includes; the Yakima River, and the upper and lower Willamette River.
Northern Pikeminnow
Ptychocheilus oregonensis
Species Infromation
Description:
Northern Pikeminnow, not to be confused with Northern Pike (Esox lucius), are dark or dusky green back, with a silver, creamy, or white belly, and clear fins. They have a long snout with a large toothless mouth which extends back to the eye. They can reach up to about 35 inches, they have a deeply forked tail and large scales.
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Impacts:
Northern Pikeminnow are known to consume millions of juvenile salmonids throughout the Columbia River Basin.
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Native Range:
Northern Pikeminnow are native to western North America and can be found in lakes or bodies of water that are slow moving.
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What to do if Encountered:
If caught, do not release back into the water alive, check with Washington State on bounty reward programs, and report your findings to the Nez Perce Tribe's Aquatic Invasive & Nuisance Species Program @...
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AINS Program Lead, Clark Watry at 208-621-3549
AINS Biologist, Anthony Capetillo at 208-621-3553
Invasion Timeline
1991
1998
2023
Northern Pikeminnow sport reward program to protect juvenile salmonids in the Columbia River Basin begins.
Northern Pikeminnow officially gets its name changed from the formally known, more offensive name.
Nez Perce Tribe Aquatic Invasive & Nuisance Species Program begins looking at Northern Pikeminnow as a predatory nuisance species and starts exploring management options.