Invasive Plants and Animals

Water Chestnut

Non-native (or exotic) species are plants and animals that were brought to an area from another region. Many of these species do not have natural predators in their new homes to keep their populations in check, and they often spread rapidly. A species that is able to invade and disrupt an ecosystem, often out-competing the native flora and fauna, in considered invasive.

Invasive species of aquatic plants that are established or have been identified in the watershed include:

Floating species:
Water chestnut (Trapa natans)
Water hyacinth (Eichhornia crassipesz)
Water lettuce (Pistia stratiotes)
• European water clover

Submerged species:
Variable milfoil (Myriophyllum heterophyullum)
Eurasian milfoil (Myriophyllum spicatum)
• Fanwort (Cabomba caroliniana)
• Curly-leaved pondweed (Potmogeton crispus)

Emergent wetland species:
• Purple loosestrife (Lythrum salicaria)
• Common reed (Phragmites australis)

Other invasive plant species listed by Mass DCR’s Lakes and Ponds Program include: swollen bladderwort, European naiad, South American waterweed, yellow floating heart, and hydrilla. Potential invaders include: hygrophila, parrot feather, and zebra mussel.

What OARS is doing!
Organizing volunteer water chestnut hand-pulling events.
Mapping and managing invasive water chestnut.

What can you do?
Volunteer to help pull water chestnut. OARS has been working to manage water chestnut on the Assabet River since 2008, and since 2012 to map water chestnut and other invasive aquatic species in the watershed.

Prevent the introduction of invasives: The International Waterlily & Water Gardening Society also compiles a comprehensive list of state-regulated invasive aquatic plants. Check the IWWGS and Mass. List of Prohibited Plants before buying any plant for water gardening, and never release non-native plants to our local ecosystem.

Prevent the spread of invasive aquatic plants and animals - Aquatic Hitchhikers!:
• Remove all plants and animals from boat, trailer, anchors, fishing gear and diving gear.
• Flush engines and dispose of bait, bilge water and bait bucket water on land away from shore.
• Never release any plant or animal into a body of water, unless it came out of that water.
• Dispose of all foreign matter far from water.
• Always check your boat, trailer and gear before entering or leaving a waterbody.

References and links:
Invasive Plant Atlas of New England
New England Wild Flower Society
SuAsCo Cooperative Invasive Species Management Area
Massachusetts Lakes and Ponds Program