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Are chemicals making mussels sick?

CMU researchers simulate effects of contaminated waterways

Contact: Heather Smith

​The next time you pour a drink of filtered water, you can raise your glass to a natural ally: freshwater mussels.

Each one filters bad stuff out of water to the tune of 60 gallons a day.

But today's mussels have a lot more on their plates than the fine organic matter their ancestors enjoyed back in the day. The menu now includes herbicides, medicines, toothpastes, perfumes, deodorants and any other chemicals that find their way into the water system.

And it's taking a toll. According to Daelyn Woolnough, a faculty member in Central Michigan University's biology department and Institute of Great Lakes Research, of about 45 mussel species in Michigan and some 300 in North America, around three-quarters are rare or in danger of extinction.

Mount Pleasant mussels

Woolnough is leading CMU research of the problem. More than $300,000 of Great Lakes Restoration Initiative money is being provided through a partnership with the U.S. Fish and Wildlife Service.

To get it started, Woolnough and her six student researchers brought 120 freshwater mussels to the vivarium — a controlled area where animals can be studied — at CMU's Biosciences Building. All mussels were collected from the Grand River near Lyons, Michigan, in Ionia County.

The U.S. Fish and Wildlife Service recently provided 200 largemouth bass from a Michigan hatchery.


Bass — and several other species of fish — are vital to mussel reproduction. An adult female mussel will mimic prey to nearby predator fish. The fish attacks and is sprayed with mussel larvae.

The microscopic larvae, attached to the gills "like tiny Pac-Men," in Woolnough's words, take nourishment from the fish and hitch a ride. They grow into juveniles and fall off after about 20 days.

Controlled experiments

Two vivarium rooms are dedicated to the research. In one, both species are kept in small tanks with low, medium and high mixes of agriculture chemicals, such as herbicides, insect repellants and substances added to plastics.

The other has urban bass and mussels embed2.jpgmixes such as antidepressants, diabetes medications, fragrances and personal care products such as soaps.

Each room also has a control tank containing no chemicals. The species will be kept separate until the researchers introduce the mussel larvae to the fishes' gills.

After the mussels drop from their hosts they will be counted under a microscope and checked for abnormalities.

The health of the bass will be checked, too. After all, no hosts, no grown-up mussels.

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