A new bill making its way through the federal legislature aims to stop the spread of invasive aquatic species including zebra mussels in the Colorado River and other western United States waterways. 

Rep. Joe Neguse, D-Colorado, introduced the bill on Tuesday, Dec. 3, in the House while Sens. Michael Bennet, D-Colo., and Steve Daines, R-Montana, take a companion bill through the United States Senate. 

The bill — aptly titled the “Stop the Spread of Invasive Mussels Act” — would strengthen partnerships between the U.S. Bureau of Reclamation and state and local governments to fund and implement preventative programs such as watercraft inspection and decontamination stations. It also proposes that any federal agency involved in the Aquatic Nuisance Species Task Force will have the authority to limit the movement of invasive species into and out of U.S. waters and seek to improve data sharing between agencies. 

“We have to do everything we can to protect our rivers, lakes, and waterways that are vital to our local communities and outdoor recreation economy,” stated Bennet in a release. “This legislation invests to reduce the spread of invasive species in Colorado – saving money for taxpayers and ensuring the health of our ecosystems.”

A recent detection in Colorado was the impetus for the bill, according to a news release from Neguse’s office.

Dan Gibbs, executive director of the Colorado Department of Natural Resources, added that the bill’s proposed resources are “needed now more than ever to protect our state’s waterways and critical infrastructure” in light of this discovery. 

Zebra mussels veligers, the species’ free-floating larvae, were found in the Colorado River in early July near Grand Junction and the Government Highline Canal. This was the second time the invasive species was found in the state following detection in 2022 at the Highline Lake near Grand Junction, a lake fed by the Government Highline Canal. 

The invasive species, known for its rapid reproduction rate, can have devastating ecological and infrastructure impacts. Its presence in the Colorado River and other waterways can have negative impacts on fish populations since the mussels can kill off essential prey items including plankton. Once adults age, zebra mussels can also clog water infrastructure. One adult female can produce 1 million veligers in a single year.  

Between the July discovery and Nov. 1, Colorado Parks and Wildlife took 450 samples from the Colorado River, Government Highline Canal, James M. Robb-Colorado River and Highline Lake State Parks, as well as additional areas throughout the Grand Valley. Additional samples were taken by the Bureau of Reclamation and the Grand Valley water entities. 

It did not find any additional veligers or adult zebra mussels in these samples, making their initial presence somewhat puzzling to agency officials. 

During this time, the agency also increased its educational outreach efforts in the region, sharing the importance of clearing, draining and drying all watercraft and equipment. 

While the 450 samples mark the end of Parks and Wildlife’s efforts this year, it will resume its testing for invasive species in the spring. With the recent detections, the Colorado River and Government Highline Canal will be subject to increased testing over the next five years. 

Parks and Wildlife also drained Highline Lake as part of its plan to eradicate zebra mussels from the lake in mid-November. Staff at the Highline Lake State Park discovered five, dead adult mussels in November during routine inspections. The lake will stay empty throughout the winter to expose as many areas as possible on the lake bed and shoreline, eliminating any remaining veligers or adult zebra mussels. 

The invasive species have been found in other western waterways, including in Lake Powell, where they were discovered in 2012. 

“The spread of invasive mussel species continues to be a risk to water bodies throughout the nation and will have a significant impact for all water supplies and infrastructure, including the water projects that were built by the Bureau of Reclamation,” said Chané Polo, executive director of the Colorado Water Congress, in a statement of support for the new legislation. 

Polo said the proposed legislation would provide “necessary authorization, funding and allow additional partnerships to be developed to support (inspection and decontamination) programs on federal reservoirs, where the inspection and decontaminations are highly effective at preventing the spread of mussels.”