Aquatic invasive species (AIS) pose a grave and growing threat to the Greater Yellowstone Ecosystem. An AIS is a freshwater or marine organism that has spread or been introduced beyond its native range and is either causing harm or has the potential to cause harm. AIS can quickly and drastically transform habitats and food chains, causing permanent declines in fish and food resources for native wildlife. At least eight AIS already exist in Yellowstone's waters: New Zealand mud snail, red-rimmed melania, five nonnative fish, and whirling disease.

Our Goals

We promote aquatic invasive species awareness and communicate how to prevent them from spreading.

Using Clean, Drain, Dry procedures is an effective way to stop the spread of AIS. Some invasive species, such as mussels, can survive as long as 30 days out of water.

We work with partners to inspect incoming watercraft for aquatic invasive species.

Yellowstone National Park, Grand Teton National Park, and surrounding states aim to inspect all boats entering the region before launch to maximize protection of park and surrounding waters and minimize inconvenience to visitors.

We monitor Yellowstone waters for aquatic invasive species.

Early detection of AIS, including the use of environmental DNA surveys, can prevent the accidental spread to other areas.

Preventing Aquatic Invasive Species

Prevention is the best tool in AIS management. Once an AIS is established in an area, it’s usually impossible to eradicate, or the eradication methods come with serious environmental consequences. Also, controlling an established population is difficult and expensive. Yellowstone works to prevent new AIS from entering the park through public education and awareness, a permit and inspection process, and aquatic resource monitoring.

Education & Awareness

The Stop Aquatic Hitchhikers! national education campaign was launched by the Aquatic Nuisance Species Task Force in 2002. The goals of the campaign are to raise awareness, change behaviors, and build community capacity to stop the spread of aquatic invasive species across the United States and beyond. Currently, there is a network of over 1,400 campaign partners across the country.

As a proud Invasive Species Action Network partner, Yellowstone empowers recreational users of aquatic resources to “Clean, Drain and Dry all watercraft, trailer, motors, and gear every time, everywhere.”

Inspections & Permits

Yellowstone has a dedicated team of inspectors who examine all watercraft before they enter park waters. Visitors play a crucial role in protecting Yellowstone’s waterways by cleaning, draining, and drying their watercraft before arrival. Together, these efforts help prevent the spread of harmful aquatic invasive species.

Before launching in Yellowstone, ALL watercraft—both motorized and non-motorized—must pass a Yellowstone AIS inspection to receive a permit. This requirement includes but is not limited to:

• Any boat with a motor
• Canoes
• Kayaks
• Paddleboards
• Inflatable boats & angler float tubes

Monitoring & Early Detection

Yellowstone biologists monitor the distribution of known AIS populations and screen for new populations or introductions. Monitoring efforts are focused on quagga and zebra mussels in waters open to boating or with high recreational use. Early detection of AIS is key to limiting the spread and preventing introduction into additional waterways. Park researchers utilize several techniques to monitor for AIS, including environmental DNA sampling, plankton sampling for veligers (the microscopic juvenile stage of mussels), and visual surveys for invasive plants and invertebrates.

Report Sightings

If you think you’ve found a new AIS in Yellowstone, note its location, take a photo, and contact us immediately.

Incoming Threats

The greatest threat to Yellowstone’s aquatic resources is from zebra and quagga mussels. In recent years, they have been detected in Colorado, Idaho, and South Dakota. Yellowstone, Wyoming, and Montana are currently mussel-free. To reduce the risk of spreading AIS, Wyoming and Montana have increased staff and inspection stations. Biologists from Yellowstone, Wyoming, and Montana will continue to monitor aquatic resources and may implement additional preventative measures.

If nonnative mussels are detected in the Greater Yellowstone Ecosystem or surrounding area, park managers will consider a temporary closure of all park waters to all watercraft. If nonnative mussel larvae or adults are found in Yellowstone, all park waters would close to all watercraft (except authorized boats) to prevent the spread to other waterways. The park is currently developing an AIS rapid response plan.

Questions & Answers

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