VIDEO: Mussels coating ancient reefs in Lake Michigan

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When people talk about restoring the Great Lakes, they’re not looking back as far as John Janssen, professor at the University of Wisconsin-Milwaukee School of Freshwater Scientists.

“I want to bring the coral reefs back,” Janssen said.

Ancient coral reefs are peppered throughout some of the Great Lakes where glaciers carved out tough rock formations 400 million years ago.

Remnants of reefs can be seen on the eastern side of Lake Michigan, the Bruce Peninsula of Lake Huron, the southwestern side of Lake Erie and near Niagara Falls. Lake Superior is the only lake that never had reefs.

In 2001, Janssen shot a video of an ancient reef outside of Highland Park, Ill.

If he were to go back and take more footage today, the scene would be quite different. The zebra mussels would be replaced with quagga mussels, and round gobies would be appearing in abundance.


Footage taken by John Janssen of the Great Lakes WATER Institute, University of Wisconsin-Milwaukee

Video provided by the Great Lakes Environmental Research Laboratory – GLERL

Featured image: Wendy S. Smith (Flickr)

4 thoughts on “VIDEO: Mussels coating ancient reefs in Lake Michigan

  1. Lake Michigan is the safest place in the world for any invasive species, including Asian Carp. This is by design. At the Asian Carp meeting yesterday Portage Indianna. Asian Carp spawn at 65 degrees, spawn more during high water, but spawned during low water as well. Plenty of food here, they can eat muck. A fouth barrier is planned for Chicago, (sound like they’re planning to close the canal to you?) Most plans/actions are 5 year studies. If asian Carp continue to double every year, how many will we have in 5 years? High tech will not control Asian carp, only cost money, lots of money. $75 million in barriers so far, that’s just Chicago. From everything i’ve seen once they start spawning the end comes fast. We have native predators for Asian Carp/invasive species if we don’t use them, the shames on us. I see a lot of woulda, coulda, shoulda, in our future.

  2. Perhaps in an effort to write this piece with efficient wording the writer has taken a few too many liberties with the geologic facts.

    Consider the statement “…glaciers carved out tough rock formations 400 million years ago.” There were no glaciers here 400 million years ago. Michigan was in the southern hemisphere tropics. See for a map of the world in Devonian time. Thanks to that tropical climate, and appropriate sea depths, reefs did flourish here then, but they were not attacked by glaciers until the Pleistocene (our most recent period of glacial activity).

    Also, I find it hard to believe that Janssen said “I want to bring the coral reefs back” if he were referring to the Great Lakes. There are no known fresh-water corals.

  3. The primary reason why exotic species become such a problem is because the native species are not adept at controlling their populations. Quite to the contrary, many of these exotic species tend to hamper the success of the native species. In the case of Zebra and Quagga Mussels, which are filter feeders, they remove many of the food sources which native fish depend upon.

    The Great Lakes ecosystem is very complex and there are no simple and easy solutions to the careless and destructive introduction of exotic species into the lakes. Even so, working to restore native fish populations should be our primary goal…but understand that it will not be a magical “cure-all” for the massive problems we have created.

  4. Native Yellow Perch feed heavily on zebra/quagga mussels, and gobies. If you google (Biotic resistance on the increase:native predators), you will see the mussels or any invasive species can be controled. Sufficent numbers are required. Had they only planted say, 10,000 Salmon for the alewives, you could say. salmon feed heavily on alewives but not enough to control them. (current statement for Perch) It wasn’t until they planted predators heavily (salmon) until reductions or control of alewives occurred. Perch retain the least PCB of any fish in the Great Lakes, (Salmon are in the top 3 worst, fat content) Restoration of native fish would put serious predator pressure on all the fish from out of town. Right now we have invasive pressure the results are obvious.

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