Aquatic invasive species (AIS) are plants, animals and diseases that do not naturally occur in our waters and may cause harm to the environment, the economy, human health or natural resources.
Lake Elmo lake is facing challenges from multiple invasive species, including:
Eurasian watermilfoil (since 2005, see MN DNR Lake Elmo)
Curly-leaf pondweed (since 2024)
Zebra Mussels (discovered in 2025)
Additionally, there is a Do Not Eat fish consumption advisory for PFAS (since 2018, see PFOS)
Forms dense mats at the water’s surface.
Overtakes habitat and outcompetes native aquatic plants, potentially lowering diversity.
Provides unsuitable shelter, food, and nesting habitat for native animals.
Forms dense mats at the water’s surface.
Overtakes habitat and outcompetes native aquatic plants, potentially lowering diversity.
Provides unsuitable shelter, food, and nesting habitat for native animals.
Midsummer die-offs can litter the shoreline with dead plants.
Can encrust equipment, such as boat motors and hulls, which reduces performance and efficiency and is costly to clean and repair.
Swimmers and pets can cut their feet on zebra mussels attached to rocks, docks, swim rafts and ladders.
Filter tiny food particles out of the water, which can reduce available food for larval fish and other animals, and can increase aquatic plant growth as a result of increased water clarity.
Can attach to and kill native mussels.
