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Aquatic Nuisance Species
Aquatic Nuisance Species
Ashlee Wallace, Park Ranger, decontaminates a boat at Highline Lake State Park using high pressure.
Aquatic Nuisance Species Stamp Required in Colorado Waters
Motorboats and sailboats must have an ANS Stamp prior to launching in Colorado waters.

Boat owners are required to purchase the ANS Stamp and operators must retain proof of purchase (electronic or printed receipt) on his or her person, the motorboat or sailboat, when operating the vessel (C.R.S. 33-10.5-104.5). 

  • Motorboats and Sailboats from Colorado - $25.00
    • Colorado residents will purchase the ANS stamp at the time of registration. ​If you register/renew your vessel online or via a registration renewal postcard, the cost of the ANS stamp appears as part of your total amount due. You do NOT need to manually add another $25 to your payment for the ANS stamp.​
    • Residents with motorboats or sailboats documented by the U.S. Coast Guard or otherwise exempt from in-state registration can purchase the ANS stamp online at​, or at any CPW office or sales location​​. ​

​Funding contributes to prevention and management of ANS in the state. Thank you for protecting our waters and contributing to conservation in Colorado!

​To learn more about the ANS Stamp, see our Frequently Asked Questions​. ​


ANS Plan cover

State of Colorado Aquatic Nuisance Species Management Plan

In 2020, the national Aquatic Nuisance Species Task Force approved an ANS Management Plan to protect Colorado waterways from invasive species.

Listen to the Story: Aquatic Nuisance Species​

Aquatic nuisance species wreak havoc on ecosystems, outdoor recreation, hydroelectric power equipment, and the economy. When dreaded mussel larvae were discovered  at Green Mountain Reservoir in August, state leaders sent a plea for help all the way to the White House.

As part of the Connecting the Drops series, KGNU's Hannah Leigh Myers joined a Colorado Parks and Wildlife team as they took samples at Green Mountain Reservoir in an effort to ward off the invasive mussels and keep Colorado waters safe from threatening species​.

Listen to the interview on Water Education Colorado​.​​

​​​​​​​Aquatic Nuisance Species (ANS)

Aquatic Nuisance Species (ANS) are aquatic plants and animals that invade lakes, reservoirs, rivers and streams. Examples of ANS include:

  • ​​Zebra mussel
  • Quagga mussel
  • New Zealand mudsnail
  • Asian carp
  • Rusty crayfish
  • Eurasian watermilfoil. 
​ANS can also include fish pathogens and diseases, such as viral hemorrhagic septicemia (VHS) or whirling disease. ​

Top concerns:


​​Zebra and Quagga Mussels

Zebra mussels are native to the Black, Caspian and Azov Seas of Eastern Europe.  They were discovered in the Great Lakes in Lake St. Clair in 1988 and have since spread to 33 states in the United States. >> Learn more.​
New Zealand Mudsnails

New Zealand Mudsnails
New Zealand mudsnails are an invasive freshwater snail. They are voracious eaters that reproduce rapidly, eating much of the available food.  >> Learn more.​​
Rusty Crayfish Rusty Crayfish
Rusty crayfish are a larger, aggressive freshwater crayfish, native to the Ohio River Basin. The rusty patches on either side of their body can sometimes identify them.​ >> Learn more​.​​
​Waterflea Waterflea
Waterfleas are zooplankton aquatic crustaceans that have a jumpy or jerky mode of swimming. They are often identified by their long tails, up to 70% of total body length.​ >> Learn more.​​

ANS Program Legislative Declaration:

The General Assembly hereby recognizes the devastating eco​nomic, environmental and social impacts of aquatic nuisance species on the aquatic resources and water infrastructure of the state. The General Assembly further recognizes the potential of recreational vessels to be a significant source of the spread of aquatic nuisance species in Colorado. Therefore, the General Assembly finds, determines and declares that the purposes of enacting this article are to implement actions to detect, prevent, contain, control, monitor, and, whenever possible, eradicate aquatic nuisance species from waters of the state and to protect human health, safety and welfare from aquatic nuisance species. It is the intent of the general assembly to foster and encourage t​​​o the greatest extent possible voluntary compliance with this article. 

It is the intent of the general assembly that prevention, containment and eradiation of aquatic nuisance species have been detected or are likely to be introduced shall be the Divisions' highest priorities.