Zebra Mussel DNA Detected in Utah’s Colorado River for the First Time
Fragments of zebra mussel DNA were recently detected in the Colorado River in Utah for the first time, prompting the Utah Division of Wildlife Resources and partner agencies to urge heightened vigilance among watercraft users to prevent the spread of aquatic invasive species across regional waterways.
Environmental DNA Sampling Reveals Emerging Threat
The detection of environmental DNA in the water indicates the presence of an animal somewhere upstream, though it does not confirm that live mussels are present, according to the Utah Division of Wildlife Resources (DWR). Zebra mussels represent an emerging threat throughout the Upper Colorado River basin. State and federal agencies note that an established infestation was previously documented near Loma, Colorado, in 2025.
“Once established, zebra mussels can clog pipes and infrastructure, create recreation hazards on rocks and beaches, and alter ecosystems,” said Lt. Bruce Johnson, Utah Department of Natural Resources Law Enforcement Aquatic Invasive Species Statewide Operations Lt. “It is critical for anyone who uses boats, paddleboards, kayaks and any other watercraft to adhere to all the laws and to clean, drain and dry their watercraft in order to prevent these aquatic invasive species from spreading further into Utah.”
Timeline of Discovery and Monitoring Efforts
DWR began sampling for invasive mussels in the Colorado River in 2025, covering the stretch from the state line down to Moab, Utah. In June and July, an environmental DNA autosampler was deployed at a new location near the Potash Boat Ramp, situated approximately 14 river miles downstream of Moab.
The automated device collected daily water samples, which were subsequently analyzed by the U.S. Geological Survey for zebra and quagga mussel DNA. Out of 22 samples collected during that period, four tested positive for zebra mussel DNA. Meanwhile, environmental DNA and veliger (larval) samples collected this spring and summer from other monitoring locations along the Utah stretch of the Colorado River returned negative results.
State wildlife officials continue to coordinate monitoring operations with the U.S. Geological Survey, the National Park Service, and the Bureau of Land Management to evaluate the full status of the mussels within the state’s river corridors.
Mandatory Compliance and Preventive Actions for Water Users
Utah regulations require all river users—including individuals operating nonmotorized watercraft such as canoes, paddleboards, and rafts—to complete the state’s annual mussel-aware boater course. The educational program informs river users about the ecological risks posed by invasive species and how to help protect all of Utah’s waters from this threat.
Additionally, anyone wishing to launch a motorized boat in Utah must pay an annual aquatic invasive species program vessel enrollment fee, which directly funds DNR operations aimed at keeping AIS from spreading around Utah.
“As one of the primary users of the Colorado River, nonmotorized boaters are our first line of defense in helping reduce this risk of transporting this species from the Colorado River to other waters in the state,” said DWR Sportfish Coordinator Trina Hedrick. “All boaters are encouraged to clean, drain, and dry all watercraft when moving between waterbodies to help prevent the spread of aquatic invasive mussels. There is no time like right now to get serious about this threat.”