Tag: zebra mussels

AIS continues to spread in Minnesota

tiny-zebra-mussels-on-the-back-of a-hand
Zebra mussels can clog water supply inputs creating problems for homeowners and municipalities

It’s still early in season for AIS detection, but zebra mussels continue their march through Minnesota. As of June 29, 11 new zebra mussel infested water bodies were added to the MN DNR’s Infested Waters List: 6 in Wright County, 2 in Otter Tail County, and 1 each in Hubbard, Kandiyohi, and Stearns Counties.

In addition to these new zebra mussel infestations, Eurasian watermilfoil was confirmed in 1 lake in Le Sueur County and starry stonewort was confirmed in 1 lake in Kandiyohi County.

Mercury rising in zebra mussel infested lakes

Clearer water from zebra mussels? Yes. Healthier water? NO! But do zebra mussels impact the fish we eat? YES!!!

In their 2022 Annual Report, the University of MN AIS Research Lab (MAISRC) reported some startling findings about “how zebra mussels influence food webs supporting walleye and yellow perch, and how food web changes influence mercury concentrations in fish tissue.”

“Mercury in fish tissue was, on average, 66% higher for adult walleye and 91% higher for adult yellow perch in lakes containing zebra mussels compared to those in uninvaded lakes.

On average, mercury concentrations in 16-inch walleye from lakes containing zebra mussels were 0.28 pm, above the 0.2 ppm threshold triggering human consumption advisories by the Minnesota Department of Health.”

This is really a significant finding, and the MN Health Department advisor should be heeded.

For more information, check out this MAISRC project online at z.umn.edu/AIS-walleye

Rare report of zebra mussel attached to lake chub

Photo: Jaclyn Hill

No, this is not news from The Onion, but a research report published in Biological Invasions on March 6, 2023. This was a rare case of a zebra mussel attached by byssal threads to the lateral scales of a 6” lake chub. In the abstract, the authors note that Charles Darwin had previously recognized the potential for this kind of animal-assisted dispersal to occur. Also of note is that in 1882 Darwin published research entitled “On the dispersal of freshwater bivalves”