St. George • A state agency is preparing to put poison in in Washington County reservoir in southwestern Utah to kill off unwanted fish that were dumped illegally.

The Spectrum reports that state Division of Wildlife Resources biologists over the summer found yellow perch, bluegill sunfish and green sunfish in Kolob Reservoir and say those fish pose a threat to other fish in the lake.

The reservoir's water level is being lowered prior to a rotenone treatment scheduled for early next week.

The division has lifted fishing gear restrictions and raised the trout limit for the reservoir so anglers can take fish that will be lost when the treatment occurs.

The reservoir will be closed to the public from Sunday to Nov. 1, and trout will be restocked into the lake next spring.