Be On the Watch for Eurasian Watermilfoil

Identifying Eurasian Watermilfoil: Submerged, limp aquatic plant 12 to 21 leaflet pairs per leaf. Whorls of 4 feather-like leaves around the stem. The native look alike, Northern watermilfoil can be identified by its lesser number of leaflets, typically, 10 leaflets or less per leaf.

By Zach Peklo, NCCISMA Invasive Species Technician

Eurasian watermilfoil is an invasive plant that plagues many of Michigan’s lakes.  Submerged below the water’s surface, this limp aquatic plant has four delicate leaves arranged in a whorl around its stem. Each leaf is typically comprised of 12 to 21 leaflet pairs.  Eurasian watermilfoil can tolerate a wide range of pH’s, water depths, salinities and temperatures, allowing it to colonize in a variety of habitats such as ponds, lakes, slow moving rivers, reservoirs, and brackish waters.

Eurasian watermilfoil offers little nutritional value for waterfowl species.  Its dense growth shades out native vegetation, often resulting in monocultures.  Dense patches of Eurasian watermilfoil inhibit water access, impeding activities such as swimming, fishing and boating.

First documented in Washington D.C. around 1942, this common aquarium plant did not take long to spread throughout the U.S.  Now found throughout most of North America, Eurasian watermilfoil’s rampant spread can be attributed to its ability to establish from just a tiny fragment.  With this trait, it can hitch hike on trailers, boats, kayaks or other equipment being transported from water body to water body.  For this reason, following the steps of the clean, drain, dry slogan are especially important in stopping the spread of Eurasian watermilfoil.

Eurasian watermilfoil is one of five invasive species monitored in the Exotic Aquatic Plant Watch (EAPW) program.  In this program volunteers learn how to detect, monitor and respond to invasive aquatic plants in lakes.  Early detection and rapid response is critical to preventing damaging invasions. Many lakes within the region already have occurrences of Eurasian watermilfoil and are currently conducting treatments to address these infestations.

For more information about invasive species or the EAPW, contact

NCCISMA at (231)429-5072 or email at vicki.sawicki@nullmacd.org.