(2013-519 Oct. 16)
The Washington Department of Fish and Wildlife (WDFW) intends to chemically rehabilitate Spectacle Lake in Okanogan County with the aquatic pesticide rotenone during the week of October 28th through November 1st, 2013. Typically, lake rehabilitations only take one to three days to complete; however, treatments may take more time depending upon weather, equipment breakdowns, logistical constraints, and/or water quality conditions.
Rotenone is a naturally occurring and organic compound classified as a pesticide by the Environmental Protection Agency (EPA) due to its relative toxicity to fish. Rotenone is non-persistent in the environment and non-toxic to humans, livestock, and other warm-blooded animals at concentrations used to eradicate fish. The two formulations of rotenone that will be used during treatment include liquid and powdered. The percentage of active ingredient in each formulation is 5.0% for liquid and ranges from 6.0-8.0% for powdered. Target concentration of rotenone in Spectacle Lake will be less than or equal to 2.0 parts per million. Rotenone toxicity normally lasts one to four weeks, but may persist for up to eight weeks depending upon water quality conditions. The target fish species for eradication in Spectacle Lake is yellow perch, bluegill sunfish, smallmouth bass, and largemouth bass. Rainbow trout will be planted into these lakes the following spring.
Notices will be posted along the shorelines, public boat launches, and other areas of normal access to the water. Please obey the following use restrictions within the posted treatment area:
1. No fish can be taken and eaten from the lake during the treatment period.
2. Do not use water to irrigate crops during the treatment period.
3. Do not use as a potable water source during treatment period.
4. Do not swim in the lake until the rotenone product is thoroughly mixed.
The above list details the water use restrictions applicable to Spectacle Lake for the duration of rotenone toxicity. Rotenone toxicity will persist for 3 to 8 weeks. Assays will be done to determine lake toxicity, and water use restrictions will be removed when the lake detoxifies.
For more information concerning the treatment, contact the applicator, WDFW, Region 2 Fish Program Manager, Jeff Korth, 509-754-4624, ext. 224 or District 5 Fish Biologist, Chad Jackson at 509-745-4624, ext. 250.
This pesticide treatment is regulated under permit by the Washington Department of Ecology Water Quality Program, Eastern WA Regional Office, 509-456-2926. These pesticides have been approved for this purpose by the Environmental Protection Agency and the Washington Department of Agriculture.
Published by Omak-Okanogan County Chronicle.