Great Lakes mussels and algae threaten migrating loons

By on December 13, 2013
Loon in Wisconsin (Credit: Kelly Sikkema, via Flickr)

Loon in Wisconsin (Credit: Kelly Sikkema, via Flickr)

A weather-dependent combination of invasive mussels and thriving harmful algae may be a recipe for loon die offs in the Great Lakes, according to a report from

The last several years residents in Wisconsin, Minnesota and Michigan have seen die offs of migrating loons stopping in Lake Michigan.

Severity of the die offs seems to relate to yearly weather.  During hot, still years when the water is prime for algal growth, loons tend to die in higher numbers. In 2012, thousands of dead juvenile loons washed ashore. 2013 has been much less severe.

Invasive quagga mussels filter Lake Michigan’s water.  It allows more light to fuel growth of cladophora algae.

Cladophora produces a botulinium neurotoxin. Once the algae die they release the poison, which can paralyze and eventually kill loons hunting for food.

Image: Loon in Wisconsin (Credit: Kelly Sikkema, via Flickr)

About Austen Verrilli

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