New Zealand Mudsnails
New Zealand Mudsnails Confirmed In Canyon Creek
May 1, 2023
Anglers and others recreating in Canyon Creek are now required to clean, drain, dry and decontaminate their equipment after each visit
The Arizona Game and Fish Department (AZGFD) has added Canyon Creek to its list of "Aquatic Invasive Species Affected Waters" (also known as Director's Order 2) after recently confirming the presence of invasive New Zealand mudsnails in lower Canyon Creek about 3 miles downstream of Canyon Creek Fish Hatchery.
Director's Orders are authorized by ARS §17-255.01 and include lists of aquatic invasive species and waters, as well as decontamination protocols.
What This Means For You
What does this mean for you? Anglers and others who recreate at Canyon Creek are now required by law to clean, drain, dry and decontaminate their equipment as prescribed in Director's Order 3 before using in another Arizona water, just as they are required to do so at other waters having New Zealand mudsnails or other aquatic invasive species (AIS). Other waters confirmed as having New Zealand mudsnails are: Oak Creek, Verde River below Bartlett Dam, lower Salt River from confluence of Verde River to Granite Reef, Lake Mead, Lake Mohave, and the Colorado River from Davis Dam to I-40.
Cleaning, draining, and drying watercraft, equipment and fishing gear is an effective way to prevent the spread of AIS to other locations. Below are the requirements for decontaminating your waders, equipment and gear.
Requirements For Decontaminating
• After fishing, scrub the bottom of boots or waders with a brush to remove all mud, plants and other organic materials. Then choose one of the following options before using the equipment and gear in the next body of water:
• Option 1: Submerge waders and gear in a large tub filled with a quaternary ammonia-based institutional cleaner. If using consumer-grade 409*, the solution does not need to be diluted. If using a product such as Super HDQ Neutral*, mix 6 ounces per gallon of water. Equipment must be soaked for at least 20 minutes, scrubbing and inspecting all items before rinsing. The rinse water must be from a source free of AIS (to avoid re-exposure), and the chemical bath must be properly disposed of away from the body of water.
• *Note - The Arizona Game and Fish Department does not endorse any particular product. Mention of any brand is for example only. Additional information regarding watercraft decontamination can be found at azgfd.gov/ais.
• Option 2: Place waders and boots in a freezer overnight between uses.
• Option 3: Dry waders and equipment completely for seven consecutive days (May through October) or 18 consecutive days (November through April).
• Option 4: Spray or soak waders and gear with 140 degree Fahrenheit water for at least 10 minutes.
One Snail Can Start A 'Village'
The New Zealand mudsnail is an invasive snail that is ovoviviparous (live bearing) and parthenogenic (reproduces asexually). Therefore, it only takes one snail to start a new population. The snails are very small and can easily be tracked to other areas with waders and shoes.
These snails were first found in Arizona in 2002 in the Colorado River below Lake Powell in Lees Ferry, and then progressively moved downstream through the Grand Canyon and into Lake Mead and Lake Mohave. In 2019, they were detected in AZGFD's Page Springs Hatchery, and they are also known to exist in other Arizona waters listed above.
Compete With Natives
New Zealand mudsnails are a concern because they compete with native invertebrates for food, posing potential harm to Arizona's native and sportfish populations, as well as native mollusks.
The Arizona Game and Fish Department reminds boaters, anglers and other water recreationists to "clean, drain and dry" – and especially decontaminate - their watercraft and equipment before exiting waters designated as having AIS.
Be Stewards Of What We Love
"It is everyone's responsibility to be stewards of the places that we love," said AZGFD Aquatic Invasive Species Program Coordinator Kate Dukette. "Cleaning your gear after use is one of the best ways to protect Arizona's waters and fisheries, regardless if you are in an AIS-affected water or not."
Aquatic invasive species are non-native species that are often unintentionally introduced by human movement. They do not have predators outside of their native range, and are able to outcompete native species. They can be animals, plants and even pathogens that cause disease in native fish or other aquatic animals. They can often be invisible to the naked eye, making them even more difficult to control. Once introduced, they can alter ecosystems by interrupting food chains, cause damage to boats and other recreational gear, clog up water and power infrastructure, and pose safety hazards.
For more information on Arizona's rivers and streams go to Arizona Rivers And Streams.