What You Can Do To Prevent the Spread of Aquatic Nuisance Species

There are many ways by which non-native species may be introduced into Washington waters. Sometimes non-natives are spread by other species or they may be carried into other areas by natural events, such as a tsunami or flooding. However, most introductions related to human activities are preventable.

It is against the law to release into state waters any non-native species whether by intentional introduction or simply by a failure to act to prevent unintentional introductions. This includes animals and plants hitchhiking on boats or field gear; aquarium or terrarium pets or plants; animals or plants used in research or education; or unused live fishing bait or live seafood purchased from a store.

Transporting aquatic invasive species from one waterbody to another is illegal in the state of Washington. Violators face a maximum penalty of one year in jail and $5,000 in fines.


Boaters, kayakers, anglers and anyone who recreates or works in Washington's waters should take measures to help prevent the spread of aquatic invasive species. There are two methods recommended including the basic "Clean/Drain/Dry" and the more rigorous "Decontamination" protocols for known or suspected infested waters.

Note: Boaters and anglers should contact the Washington Department of Fish and Wildlife if they suspect their boats or gear have been used in waters of states infested with zebra or quagga mussels (see map).

Clean / Drain / Dry

This method includes:

  • Clean equipment that has come into contact with Washington's waters by removing all visible native and non-native plants, algae or mud from shoes, waders, life vests, boat hulls and engines, trailers and other gear. Use a stiff-bristled brush to clean equipment.
  • Drain any accumulated water from boats or gear – including water used in cleaning – back into the lake, stream, or other waterbody from which it came.
  • Rinse all surfaces with potable water.
  • Let boats or gear fully dry before using again.


Aquatic invasive species can be difficult to see. Therefore, the Clean/Drain/Dry method isn't always enough and additional decontamination may be necessary.

There are multiple ways to for the general public decontaminate boats, footwear and gear:

Drying method:  Once gear is fully dry, allow it to remain dry for an additional 48 hours before using again in Washington waters. This technique is not suitable for felt-soled shoes which must use one of the other methods described below.

Hot water: Hard non-porous surfaces, like trailers, engines and shovels, require constant exposure to water heated to a minimum of 140 degrees Fahrenheit for 15 seconds by soaking or using a hot water pressure washer. Porous materials and gear with multiple folds or cavities, such as boots, waders or nets, require constant exposure for in water heated to 120 degrees Fahrenheit for a minimum of five minutes. This method is not recommended for gear made of Gortex.

Freeze: Freeze your gear to a temperature of 14 degrees Fahrenheit for a minimum of eight hours or 15 degrees to 32 degrees Fahrenheit for a minimum of 24 hours.

Chemical method: Chemical treatments should not be done near a waterbody. Soak gear in undiluted antibacterial Formula 409® for 10 minutes. Rinse thoroughly in a contained area. Rinse water must be disposed of down a sewage drain, not a storm drain. Always follow label instructions before use. This method may cause surface cracking of rubber or loss of water repellency.

WDFW does not recommend other chemicals including salt water at this time as there are no published scientific studies showing effectiveness by minimum dilutions and soaking time or potential effects on gear.

Inspecting and decontaminating your watercraft for Quagga & Zebra Mussels
Aquatic Nuisance Species Management Plan
Tunicates Fact Sheet
Zebra Mussel (Quagga) Fact Sheet
Ballast Water Rules
STOP the spread of Aquatic invasive Species

to transport or spread
Aquatic Invasive Species

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