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It's the Law

Invasive Species

What Are They?

Invasive species are plants or animals, either indigenous to this region (native) or from other regions (non-native or exotic), that have the ability to dominate or alter an ecosystem. Most exotic species originally arrived in ballast water or were intentionally or accidentally released from aquariums. Invasive species often are spread by remaining on boat trailers, propellers, and fishing gear, or in a bait bucket, cooling water, and live well water.

Various nuisance species

Why Are They Harmful?

Interference with boating and fishing: Many invasive plants grow rapidly in our lakes. The dense mats of vegetation they form can restrict or entirely prevent boating and fishing and may make the waterway entirely impassable.

Loss of native plants and animals: Non-native plants often do not provide ideal habitat or food for fish and other aquatic animals. These plants crowd out native vegetation, and the fish and animals that depend on native vegetation must relocate or perish.

Loss of biodiversity: The spread of invasive species often reduces the biological diversity of the area and can disrupt the balance of the ecosystem.

Loss of property value: The aesthetic appeal, recreational value, and surrounding property values of a lake may decline quickly as an invasive species takes over.

Expensive: Once exotic plants are established, they are almost impossible to eradicate and are expensive to control. The United States invests millions of dollars annually to manage these plants and repair the damage.


Remove all plant parts, animals, mud, and other debris from your boat motor, trailer, anchors, fishing gear, and dive gear. Dispose of plant and animal matter, mud, and other debris above the waterline on dry land or in a trash can.

Pull all drain plugs and allow any standing water to drain completely; dispose of live well, bait, and cooling water away from the shore before leaving the area.

Never release a plant or animal into a body of water unless it came out of that body of water.

Wash your boat (see the Cleaning Solutions chart), and allow it to dry completely before entering another body of water.

  • Your boat and equipment should be allowed to dry completely for:
    • 1 week during July and August
    • 2 weeks during June and September
    • 4 weeks from October to May
  • Increase drying times if the weather is unseasonably cool or wet.
  • If your boat is exposed to freezing temperatures, it is considered decontaminated.

Familiarize yourself with invasive species by requesting one of our free color guides to invasive aquatic plants, and spread the word to others about invasive species.

Get involved. Request a free "Stop the Spread" sign for your boat ramp, or join a weed-monitoring group to identify and eradicate new infestations in your lake before they become permanently established.

Be alert for zebra mussels. They are now established in some Massachusetts waters. They are also found throughout NY, VT, and CT. Zebra mussels can destroy dive gear, boat motors, and other engines. Please report any sighting or possible infestation.

Invasive species create problems for boaters. Zebra mussels can attach in clusters on motors, and hydrilla can get tangled in propellers.

Cleaning Solutions

Disinfectant Concentration Contact Time
Steam/scalding hot wash >140°F 10 seconds
Chlorine/bleach solution 1 oz. per gallon water 10 minutes
Lysol 1% solution 10 minutes
Vinegar as sold–100% 20 minutes
Freezing <32°F 24 hours

For more information on invasive species or to report an infestation, contact the

MA Department of Conservation & Recreation Lakes & Ponds Program