Scientists say invasive mussels may be to blame for dead loons


Researchers are trying to solve the mystery of what caused the deaths of loons that died migrating across Lake Michigan, but they suspect zebra mussels may have played a role, MPR reports.

It's likely that at least some of the iconic birds that have died were from Minnesota, MPR says.

Scientists suspect invasive species could be to blame – specifically, invasive zebra and quagga mussels. The mussels trigger a complex ecosystem cycle that ultimately clears the way for a type of botulism that works its way up the food chain to the loons. The deadly toxin leaves the birds without muscle control, and in some cases, unable even to hold their head up out of the water.

The fast-evolving ecology of the Great Lakes Basin is due largely to invasive species that are devastating some of Michigan’s waterfowl, the Oakland (Mich.) Press reported. Thousands of dead loons washed ashore along Lake Michigan's northern shore last fall, the Press reports.

In one case last fall, biologists found 300 dead or dying loons and other birds on a single stretch of beach in northwestern Michigan's Sleeping Bear Dunes National Lakeshore, the Detroit Free Press reports.

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List of waterways with invasive species grows

Just in time for Minnesota's warm-weather boating season, state conservation officials Thursday released a list of waterways newly discovered to be infested with invasive species such as Asian carp, zebra mussels and Eurasian milfoil. Added were nearly two dozen lakes and stretches of the Mississippi and St. Croix rivers.

Penalties double for invasive species violations

Tougher laws aimed to prevent the spread of aquatic invasive species, like zebra mussels and spiny waterfleas, go into effect Sunday, July 1 -- doubling fines for Minnesota boaters who are caught violating the rules. The Department of Natural Resources says about 20 percent of boaters are not taking the basic precautions to comply with the laws. The new fines range from $100 to $500 dollars.