(Heber City, UT) — Utah wildlife officials are monitoring a popular reservoir after a fisherman found an invasive fish. The Utah Division of Wildlife Resources says it was contacted by an angler who caught a walleye at Strawberry Reservoir last month. Officials say they believe someone released the walleye into the reservoir, which is both illegal and harmful. The reservoir is stocked with cutthroat trout, rainbow trout and kokanee salmon, and officials warn that illegally introduced fish can prey on and out-compete native and endangered fish.