Zebra mussel DNA detected in Utah’s Colorado River for first time, raising alarm over invasive species threat across the Upper Colorado River basin |

An invasive species threat has reached a new stretch of the Colorado River, after scientists detected zebra mussel DNA in Utah’s portion of the river for the first time. The discovery has raised concerns among wildlife officials because zebra mussels can spread rapidly once established, potentially damaging infrastructure, disrupting recreation and altering freshwater ecosystems. The Utah Division of Wildlife Resources (DWR) announced the detection on 25 August 2026, saying fragments of zebra mussel DNA were found in water samples collected near the Potash Boat Ramp, about 14 river miles downstream from Moab. The finding does not confirm that live zebra mussels are present at the site, but it signals that an animal may be somewhere upstream. The discovery comes after an established infestation was documented near Loma, Colorado, in 2025, increasing concern about the invasive mussel moving further through the Upper Colorado River basin.

Zebra mussel DNA detected in Utah’s Colorado River for the first time

The Utah Division of Wildlife Resources began sampling the Colorado River in 2025, covering waters from the state line to Moab as officials monitored for invasive mussels. During June and July 2026, an environmental DNA autosampler was installed near the Potash Boat Ramp. The device collected water samples every day, which were subsequently analysed by the US Geological Survey for zebra and quagga mussel DNA. Four of 22 samples collected during that period tested positive for zebra mussel DNA. However, the DWR stressed that environmental DNA is not proof of a live infestation at the sampling location. It indicates that genetic material from a zebra mussel was detected in the water and that the animal could be somewhere upstream. Other environmental DNA and veliger samples collected from different locations along Utah’s Colorado River during spring and summer did not test positive.

Invasive zebra mussels pose a growing threat to the Colorado River basin

Zebra mussels are an aquatic invasive species capable of creating serious ecological and economic problems when populations become established. The DWR said the species is already an emerging threat in the Upper Colorado River basin, following an established infestation documented near Loma, Colorado, in 2025. Once zebra mussels establish themselves, they can attach to hard surfaces in large numbers and interfere with water infrastructure by clogging pipes. They can also create hazards for people using rivers and beaches, while their presence can alter aquatic ecosystems. Utah wildlife officials are therefore working with the U.S. Geological Survey, National Park Service and Bureau of Land Management to determine the status of zebra mussels in the river. The latest DNA detection has made monitoring especially important as officials seek to understand whether the species is spreading into Utah waters.

Utah urges boaters to clean, drain and dry watercraft

The new detection has also prompted Utah officials to reinforce prevention measures among people who use the Colorado River. The DWR is urging boaters, paddleboarders, kayakers, canoe users and other river visitors to follow measures designed to prevent aquatic invasive species from being transported between waterways. According to the agency, all river users in Utah, including people operating non-motorised watercraft, are required to complete the state’s annual mussel-aware boater course. Anyone launching a motorised boat in Utah must also pay an annual aquatic invasive species programme vessel enrolment fee. Officials are particularly encouraging users to clean, drain and dry their watercraft whenever they move between water bodies. The approach is intended to stop mussels or their larvae from hitching a ride to previously unaffected waters, where a new population could become difficult to control.