Critter of the Month: Curlyleaf Pondweed

Crulyleaf Pondweed

Curlyleaf pondweed (Potamegeton crispus) is a rooted submerged plant that quickly forms dense mats at the water surface of lakes and rivers in late spring and early summer. In late fall and early winter, it sprouts from rhizomes and turions (overwintering buds) shading out later growing native plants. Mats interfere with boating, fishing, waterfowl hunting, and swimming. Summer die-offs can form windrows of decaying plants on shore, sometimes followed by algal blooms. Curlyleaf pondweed displaces native plant communities and decay can deplete oxygen levels, leading to fish kills and impacts on other aquatic life.

Native to Eurasia, Africa and Australia, curlyleaf pondweed was first discovered in North America in the mid 1880’s. By 198, it had spread across most of the United States and Canada. It spreads by seeds, rhizomes, turions, and plant pieces that break off and float on water currents. It can spread overland to new waters by clinging to watercraft trailers, and equipment. Eradicating established curlyleaf pondweed infestations is nearly impossible. Your actions and your help in reporting new infestations are vital for preventing their spread.


What you can do to help:

*Learn to recognize curlyleaf pondweed.

* Inspect and remove visible aquatic plants, animals, and mud from boat, motors and trailers before transport.

* Drain lake or river water from bilge, livewell and motor before leaving access.

* Dispose of unwanted live bait, worms and fish parts in the trash.

* Never dump live fish or live bait into another body of water. If it didn’t start in there it doesn’t belong in there, take it back with you.

* Rinse boat and equipment with high pressure, hot water, AND/OR

* Dry everything for a minimum of five days or more before reuse.

* Report suspected new sightings – not exact location; wrap a plant fragment in a wet paper towel, place in a sealed plastic bag; and call the Minnesota Sea Grant Program in Duluth, (210-726-8712; or a Minnesota DNR Invasive Species Specialist (see, 1-888-MINNDNR or (651) 259-5100.

Reminder: Know the rules!

Specimens are needed to confirm sightings, but some jurisdictions prohibit possession and transport of invasive aquatic plants and animals. Unauthorized introduction of plants, fish, or invertebrates into the wild is illegal. Protect your property and our waters.


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