A non-native fish is causing concern in the Snake and Salmon river systems, because of its tendency to eat native fish.
Idaho Fish and Game officials believe walleye were introduced into Lake Roosevelt about 80 years ago.
Since then, the fish have migrated into the Columbia and Snake River systems, including far upstream in the Hells Canyon area.
Idaho Fish and Game fisheries biologist Nolan Smith said the number of walleye caught in a fish trap at Lower Granite Dam on the Snake River increased significantly this year.
Transponders have been placed in some of the fish to find out where they may be headed next.
The main concern with walleye is their tendency to feed on prized young salmon and steelhead in the rivers. Those are desired fishing varieties if from a hatchery, and also endangered if they are the wild variety. Many fishers seek out walleye because of the taste.
Smith said because of that, they're asking anglers to be on the lookout for them.
“One way anglers can help us is to be dialed in on their species identification, so when they do go out, and potentially encounter a walleye, they know it's a walleye, and they're able to retain that fish, throw it in their cooler, and enjoy it as a meal,” he said.
Smith stresses there is no limit to the number of walleye you can pull from the Snake or Salmon Rivers.
He also urges anglers to record when and where the fish were caught, and then report their haul to the Idaho Fish and Game regional office in Lewiston.