by Jo Latimore, MiCorps Program Director
Hydrilla is a tough plant that is tolerant of a wide range of environmental conditions and can spread by fragments, seeds, underground tubers, and overwintering parts called turions. It also has been documented growing at rates up to one inch per day, forming dense beds and thick mats in both lakes and streams. As such, hydrilla has the potential to be even worse than Eurasian watermilfoil.
At this time, the hydrilla invasion appears to be confined to a pair of private residential ponds in southwest Michigan. However, surveys are continuing to determine the full extent of its spread. The State has also begun treatment of the invasion.
This discovery should remind us all of the importance of being mindful not to inadvertently spread invasive species from one water body to another in the course of our monitoring activities. This means being sure to thoroughly clean our gear before moving from one water body to the next. We should take the same care when engaging in water-based recreational activities like boating, fishing, swimming, and waterfowl hunting, and if we engage in hobbies like water gardening or aquarium keeping. MSU Extension has highlighted recommendations for preventing the introduction and spread of invasive species like hydrilla.
MiCorps has been training volunteers to identify and monitor lakes for hydrilla for nearly 20 years through the Cooperative Lakes Monitoring Program’s (CLMP) Exotic Aquatic Plant Watch. Those training materials are available on our website. In particular, we have a video about the Exotic Aquatic Plant Watch that illustrates how to identify hydrilla. If you wish to monitor your lake for hydrilla, we will be opening up CLMP enrollment for the 2024 season very soon. Check the MiCorps Website for updates on enrollment for the next monitoring season.