A mat of pale green stems and darker green leaves fills the screen in this underwater picture.

Invasive species made a splash in Michigan this month, with the first confirmed population of Hydrilla found in the state. This aquatic plant spreads quickly and can tolerate low light and poor water quality, giving it an advantage over native aquatic species. Hydrilla grows whorls of serrated leaves on long, slender stems that can reach as long as 30 feet. Because of its potential for harming habitats and clogging waterways, hydrilla is prohibited in Michigan and is included on the state’s invasive species watchlist. Read hydrilla’s species profile on the Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS).

Despite these precautions, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) confirmed in early October 2023 that hydrilla had been found in two residential ponds in Berrien Springs in southwest Michigan. Read the EGLE press release.

Alex Florian coordinates the Southwest by Southwest Corner Cooperative Invasive Species Management Area (SWxSW Corner CISMA). He found the hydrilla while monitoring ponds previously flagged for parrot feather, another invasive plant prohibited in Michigan. Alex credits Michigan Sea Grant’s MI Paddle Stewards training program for helping him recognize and correctly identify hydrilla in the ponds. Thanks to Alex’s report, EGLE is launching a rapid response plan to chemically treat existing hydrilla plants in the ponds and prevent them from spreading into additional waterways. Learn more about SWxSW Corner CISMA and their work to educate communities and manage invasive species in Berrien, Cass, and Van Buren counties.

If you see hydrilla in Michigan waters, take one or more photos, make note of the location, date and time of the observation, and report it by:

MI Paddle Stewards is available as a free, self-paced online training module to help paddlers and resource managers identify, report, and prevent the spread of aquatic invasive species. Sign up for MI Paddle Stewards to take action in your community.