Bend, Ore. – The Oregon Department of Fish and Wildlife will close the fishing season on South Twin Lake beginning Oct. 24, one week earlier than usual. The lake will close early so fishery managers can treat the lake with rotenone to remove illegally introduced bullhead catfish and begin to restore the popular rainbow trout fishery.
The lake will be treated between Oct. 24 and Oct. 28.
According to Mike Harrington, ODFW fish biologist, the department chose to treat the lake with rotenone because it is an economical way to remove unwanted fish with little threat of long-term ecological damage. The department considered other options for the lake, including fishing restrictions, draining the lake, mechanical removal of bullhead, biological controls and taking no action.
In September, ODFW temporarily suspended all daily catch limits, possession limits and length requirements on South Twin Lake to encourage anglers to harvest any many fish as possible before treatment.
The lake will re-open to fishing next spring and ODFW plans to stock the lake with legal-sized fish as soon as the lake is accessible.
Rotenone, a plant substance, has been approved as a fish toxicant by the Environmental Protection Agency. At the concentrations used to kill fish, rotenone is not toxic to human, other mammals or birds. It breaks down completely in the environment and will not be detectable within weeks of treatment. For more information about rotenone to the ODFW website at http://www.dfw.state.or.us/fish/diamond_lake/FAQs.asp.