Aquatic invasive species thrives in winter

Aquatic invasive species not only survives Michigan winters, it thrives under the ice.

Ice Fishing on Saginaw Bay Linwood, Michigan | Photo by Michigan Sea Grant, 2002
Ice Fishing on Saginaw Bay Linwood, Michigan | Photo by Michigan Sea Grant, 2002

When winter freezes Michigan inland lakes, the threat of the spread of aquatic invasive species (AIS) does not go away. Boats were drawn out of the water, cleaned and stored for winter.  Docks that could be pulled ashore were, but then out comes the ice fishing gear. Shanties are slid onto the ice, holes are augured and a new season of sport begins and with it the spread of AIS.

Eurasian watermilfoil (EWM), zebra mussels, spiny water fleas, and Vial hemorrhagic septicemia (VHS) and several bait species can innocuously be gathered and spread around Michigan’s lakes during the winter ice fishing season. According to Montana State University Extension bulletin EB0193, “EWM can maintain a large amount of biomass throughout the winter which aids in rapid and early seasonal growth in the spring.” This means that all boater and ice fisher equipment should be carefully inspected for any bits or pieces of plant matter (under 1”) and muddy debris that could carry animal or zebra mussel larvae. One AIS Coordinator from Oneida County Wisconsin is quoted on WJFW news as saying, "Eurasian watermilfoil is considered a perennial. However, I consider it an evergreen. A lot of people do. The reason being is it's winter-hardy. It's capable to live and grow underneath the ice."

Steps winter fishing sportspersons can take to actively prevent the spread of AIS
  • Thoroughly inspect and clean all fishing equipment, line, hooks, nets, scoops and augers after each use.
  • Drain all water from equipment and containers containing fish prior to leaving the ice.
  • If you are using live bait, buy it locally from a licensed bait dealer (in Michigan) and dispose of any unused bait properly. Michigan law prohibits the use of leftover minnows in another body of water to prevent the spread of fish diseases.
  • Pack out your waste from the ice and dispose of it in appropriate waste containers.
  • Dry all your equipment for 5 or more days or disinfect it with an appropriate disinfection solution.

Doing your part to prevent the spread of aquatic invasive species in Michigan makes you one of our Clean Boats, Clean Waters heroes! For more information about the Clean Boats, Clean Waters program and aquatic invasive species contact Beth Clawson, Extension Educator. To learn more about invasive organisms and invasive aquatic plants contact Michigan State University Extension Natural Resources educators who are working across Michigan to provide aquatic invasive species educational programming and assistance. You can contact an educator through MSU Extension’s “Find an Expert” search tool using the keywords “Natural Resources Water Quality.”

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