Following the discovery of golden mussels in California, Colorado Parks and Wildlife is taking steps to prevent the invasive species from coming to the state. 

The state wildlife agency temporarily designated golden mussels as aquatic nuisance species, giving it authority to protect against the species in Colorado. The designation will last for nine months, during which time Parks and Wildlife will consider long-term regulatory solutions, it reported. 

With the designation, it becomes illegal for any person to possess, import, export, ship, transport, release, place or plant the mussels in Colorado waters. It also allows Parks and Wildlife officials to impound and require decontamination of watercraft and other items that are found to be transporting the species into the state.

Golden mussels are native to China and Southeast Asia and pose a more severe threat than the invasive zebra and quagga mussel species, according to a news release from Parks and Wildlife. 

They can attach to and colonize on various surfaces including recreational watercraft, water-based equipment, pipes, dams and other water infrastructure. This can impede and cause damage to water storage, treatment and distribution systems.

Much like the zebra and quagga mussels, their rapid reproduction rate allows them to produce thousands of free-floating larvae. 

What makes golden mussels a greater threat is their extreme tolerance to a wide range of environments as well as their ability to rapidly obtain nutrients from water at a rate 10 times that of the zebra and quagga species. 

This can lead to “ecosystem collapse as the nutrients in the surrounding waters that other organisms depend on, the base of the food chain, are depleted,” according to Parks and Wildlife. 

The October discovery near Stockton, California, was the first detection of the species in the United States. Since then, they have been found in other California waterways. 

While there are currently no reports of quagga mussels in Colorado — following previous detection in the Colorado River Basin in 2007 — Parks and Wildlife officials did find zebra mussel veligers in the Colorado River near Grand Junction and the Government Highline Canal in July. Between July and November, the agency found no additional veligers or adult zebra mussels after taking hundreds of samples. 

Parks and Wildlife also drained Highline Lake as part of its plan to eradicate zebra mussels from the lake in mid-November. Zebra mussels were first discovered in the lake in 2022, and several dead adult mussels were found during routine inspections in November.