Lake and Stream Rehabilitation: Rotenone Use and Health Risks


Published: January 2002

Pages: 71

Author(s): John S. Hisata


1976 through 1991 Proposed Lake and Stream Rehabilitation EIS's and the 1992 SEIS . The 1976 EIS analyzed the need for lake and stream rehabilitation. Subsequent Supplemental EIS's and the 1992 SEIS, analyzed alternate methods for fish control. These environmental impact assessments also investigated potential impacts of lake and stream rehabilitation to the environment. Rotenone was selected as the preferred alternative.

As stated in the 1976 and subsequent EIS's through 1988 on lake and stream rehabilitation, the Washington Department of Fish and Wildlife (WDFW) manages lowland lakes throughout the state according to public desires, recreational demands, ecosystem considerations and previous management efforts. Angler surveys (Mongillo and Hahn 1986, 1996) have shown that trout are the most popular of the state's game fish. Some lakes are managed to improve populations of warm water species such as bass, blue gill or crappie, the second most popular category of game fish reported by Mongillo and Hahn (1986, 1996). In response to these angler preferences, WDFW eliminates the undesirable problem and competitor species using rotenone in a small portion of the state's lakes where this is possible. This allows management for optimal populations of trout and selected warm water species that meet the state angler's preferences. The overall objective of the program is to meet the department's mandate by addressing public demand and improving public recreational game fish fishing opportunities. Additionally, rotenone is a valuable tool for use to maintain or restore native fish populations. Problems areas have been identified where introduced trout or char have adversely affected native trout or char populations by hybridization or competition and displacement.

In the scoping process, a request to review in detail the effects from the use of an alternative piscicide, antimycin, one of the two currently allowed piscicides, was received from the Washington Department of Ecology. However due to staff time constraints and since the scope of this review is focused on human health issues relative to rotenone, a review of antimycin was not undertaken. Higher cost has limited consideration of antimycin. If and when the use of antimycin becomes a probability, a detailed review will be undertaken.

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