Lake Chemistry Protecting Canadian Shield Lakes from Zebra Mussels?
Why have zebra mussels leapfrogged over the Canadian Shield?
Thanks to lake chemistry, Canada's Shield Lakes should be OK
In what seems like a never ending and relentless march across the continent, zebra mussels are showing up in ever greater numbers of waterways well removed from the Great Lakes.
That includes in places like Manitoba's Lake Winnipeg, and Minnesota's Mille Lacs Lake. I mentioned these two specific waterways because they're extremely important world-class walleye fisheries already plagued with hugely serious challenges. I suspect the fact that zebra mussels have invaded them recently is not entirely coincidental.
Another lake where zebra mussels have been recently detected and where they are poised to explode is Lake Mendota in Wisconsin.
Now, I am sure most readers have never heard of Mendota, after all it is only a modest 3,988 hectares in size, but it is important because it has often been called, "the most studied lake in the United States," owing to the fact that the University of Wisconsin-Madison Center for Limnology is situated on its southern shore. In addition, there's a remote sensor buoy in the lake that is part of the Global Lake Ecological Observatory Network.
You can read about the impacts here, and at the same time subscribe to the Centre's blog, which I always find fascinating.
Indeed, as everyone who fishes in southern Ontario, Quebec and Manitoba is aware—and as University of Wisconsin Professor Jake Vander Zanden confirms in the blog—there is no stopping zebra mussels once they wend their way into a lake, river, reservoir, pit or pond.
But the blog also raises a question that I've pondered for some time now: Why haven't zebra mussels haven't been found in the lakes and rivers scattered across the vast Canadian Shield?
Or to put it another way, why did they leapfrog over lakes like Temagami, Nipigon, Lac Seul, Lake of the Woods and the hundreds of thousands of others on the Shield, only to show up in Lake Winnipeg?
I suspect it is because Shield lakes lack the water chemistry associated with limestone and marl (calcium) basins, which is necessary for mussels to grow their shells.