by Dick Osgood
Osgood Consulting LLC

Editor’s Note: Dick Osgood is a lake management consultant based in Minnesota. Dick is past President of the North American Lake Management Society (NALMS) and is very active in lake and aquatic invasive species management throughout the upper Midwest. For more information about this author, visit his website at www.lakemanagersnotebook.com .

All the stars aligned for Christmas Lake (Minnesota).

Zebra mussels were detected early – believed to have been within weeks of their introduction. The newly introduced mussels were believed to have been contained within a very small area. Agencies, organization and individuals quickly mobilized and implemented a treatment, which was believed to have eradicated the mussels within the curtain. For insurance, a second treatment with a second chemical was performed. For even more insurance, a third treatment with a third chemical was performed. Yet, zebra mussels were found outside the containment zone again and again, requiring the barriers to be reset and retreated. Finally a large area was treated this past July.

Sadly, despite all these efforts, zebra mussels were recently discovered at the far end of Christmas Lake, meaning they are now sufficiently widespread and established to preclude further eradication or control efforts.

According to Joe Shneider, President of the Christmas Lake Homeowners Association, “It takes the very unusual case of a localized infestation and very rapid identification to have any chance. This situation might be one in a hundred. As I think about what we’ve learned at Christmas Lake, I believe that the initial treatments must occur beyond where we know there is an infestation. It seems that, at Christmas Lake the zebra mussels always moved before the barriers were set.”

What have we learned?

All of the underlying assumptions ought to be re-examined.

Were zebra mussels really detected early? Probably not, but unfortunately, there is no objective way to know for sure. Many hours of inspections conducted by qualified divers found no evidence of mussels outside the containment area. But zebra mussels are known to be illusive in the early stages of an infestation.

Were the mussels contained within the barrier? Probably not. Adult zebra mussels were found outside the barrier before and after the first treatment.

Was the first treatment using Zequanox effective? Probably, at least within the containment area. Zequanox is a natural bacterial product that is lethal to zebra mussels and nothing else. However, the application resulted in total oxygen depletion for a week following the treatment. Thus, we don’t know whether the product was lethal or the mussels died of asphyxiation.

Are the mussels now found throughout Christmas Lake from the original infestation or from a more recent introduction? We don’t know. The access through which the mussels were first introduced has been re-opened.

Here is what we should take away from this trial. Zebra mussels are pesky and we do not have the tools or techniques to detect them early enough for an effective containment or eradication. In an aquatic invasive species (AIS) plan I prepared with Dr. Dan Molloy, we referred to early detection as “early deception.” For zebra mussels and most other AIS we lack the tools for early detection as well as for an effective eradication, containment or control.

Even though all the stars were aligned in Christmas Lake, zebra mussels have become established.

It is an inescapable reality that until the underlying prevention policies are changed, more and more lakes will get zebra mussels and other AIS. According to Shneider, “I am more and more convinced that we need to consider a radical policy change from protecting access to protecting the water. When will we reach the tipping point where our legislators and the Governor recognize that the aquatic invasive species risks to our public waters cannot allow business as usual?”

There have been four newly infested lakes (with zebra mussels) in the past couple week. Shneider is correct, the AIS prevention system is broken and our lakes are suffering death by a thousand cuts.

The status quo means more and more lakes with more and more AIS.

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