Fluridone: Magic Potion or Snake Oil?

Many of you likely read the Susan Lampert Smith column “Why Not Try Magic Potion On Our Lakes” in the July 17 Wisconsin State Journal. If not, you almost certainly heard about it from your neighbors, as it caused quite a stir among lake users. For all of us feeling depressed by the floating green mats off the end of our piers, the piece revitalized our hopes for shimmering clear waters in the Yahara Lakes. In her column, Smith related the reported success of Houghton Lake, Michigan, a lake more than twice the area of Mendota, where Eurasian milfoil was eradicated through the whole-lake application of the herbicide fluridone. The lake was reported to have gone from an often unnavigable carpeted mess to clear water in six weeks, and to have stayed weed free three years later with only spot follow-up treatment.

For many of us reading the article, our first response was “Give me some of that!”

Not so fast, was the message relayed from the scientific community in a July 22 WSJ article (Ron Seely, ‘DNR Wary of Fluridone to Clear Lakes of Weeds’). Dr. Jennifer Hauxwell, a DNR researcher who has studied the use of fluridone in Midwestern lakes, doesn’t see a panacea just yet. Her initial assessment, based on a review of fluridone’s use on four Wisconsin lakes and information from 28 other states across the country indicates that the positive effects of fluridone may only last two to four years, and that weeds often come back thicker than before. The effects on fish and other species are not yet known. Furthermore, experience to date indicates that fluridone is less effective in nutrient-rich lakes such as the Yahara chain, than in nutrient-poor environments. Overall, scientSific review reveals a much more mixed bag than the rosy claims coming from fluridone’s manufacturer.

Obviously, we’re all frustrated with weeds and algae sullying our lakes. YLA has long supported and provided constructive input for the initiatives of the Dane County Lakes and Watershed Commission, designed to protect the lakes from further long term degradation. We continue to believe that such efforts are essential for the long term health of our lakes. But the idea of aggressive remedial measures to provide more immediate results is certainly attractive and should not be dismissed out of hand. Many of our members apparently agree, and have signed a petition calling on the state and county to take the fluridone idea seriously.

Still, many questions remain unanswered regarding the whole-lake application of fluridone:

• Does it work long term? Or will it ultimately make matters worse?
• What are the effects on fish and the overall lake ecosystem?
• Even if fluridone’s effectiveness is verified elsewhere, how will we know that it will work here?
• Finally, who will pay? And through what mechanism? Houghton Lake residents were assessed $1.4 million. How would we divvy the cost here?

To address these and other questions, the YLA Board has formed a working group to expeditiously focus on the issues of fluridone treatment and other whole-lake remedies. It is our intent to ensure that such remedies are given thorough consideration by our elected officials, government agencies, and the research community.

YLA will be actively involved in not only the discussion, but also in the planning and implementation of promising techniques that pass technical scrutiny. The YLA has always worked closely with the county, DNR, Wisconsin Association of Lakes (WAL), the UW, and citizens’ groups. It is those working relationships that will ensure that the voice of lake residents doesn’t ‘mire in the weeds’ while Eurasian milfoil turns our lakes to astro-turf.