Colorado Parks and Wildlife assigns temporary aquatic nuisance species designation to golden mussel

02/06/25

Travis Duncan
Public Information Supervisor
720-595-8294 / [email protected]

Colorado Parks and Wildlife assigns temporary aquatic nuisance species designation to golden mussel

DENVER – This week Colorado Parks and Wildlife (CPW) Director Jeff Davis temporarily designated golden mussels (Limnoperna fortunei), a highly invasive mussel species, as an aquatic nuisance species (ANS) “for a period not to exceed nine months.”

Although golden mussels have not yet been found in Colorado, the designation will provide CPW with the necessary authority to prevent its introduction into the state. It is illegal for any person to possess, import, export, ship, transport, release, place, or plant any aquatic nuisance species in Colorado.

“During this nine-month temporary designation, we will be considering more long-term regulatory solutions,” Davis said.

The golden mussel was detected in the California Delta near Stockton this past October and has since been discovered in several other California waterways. While this invasive species is well established in other countries, where it has been shown to have impacts even greater than those associated with the well-known zebra and quagga mussels, this is the first detection of golden mussels in the United States. 

“Much like zebra and quagga mussels, golden mussels can be transported on recreational watercraft and water-based equipment,“ said CPW Invasive Species Program Manager Robert Walters. “By implementing this temporary designation in advance of the upcoming boating season, we have the authority necessary to protect our aquatic resources from the potentially devastating impacts associated with this highly invasive species.” 

About golden mussels
Golden mussels are native to rivers and creeks in China and Southeast Asia and are known to be established outside of their native range in Hong Kong, Japan, Taiwan, Brazil, Uruguay, Paraguay and Argentina. They are highly tolerant of a wide range of environments, temperatures, pollution and low levels of oxygen, calcium and pH. Although they prefer fresh water, they are known to withstand brackish waters and estuaries. Golden mussels can also tolerate much lower levels of calcium in water than zebra and quagga mussels. The potential ecological impacts of golden mussels are even greater than those that have been seen with zebra and quagga mussels. Golden mussels attach to hard and semi-hard surfaces by releasing super adhesive filaments called byssal threads, allowing them to colonize on surfaces such as pipes, dams and other infrastructure as well as watercraft. Additionally, they are filter feeders and can dramatically reduce plankton abundance. One golden mussel can filter up to half a liter of water per hour to obtain nutrients. This is about 10 times more than zebra and quagga mussels, making them even more of a severe threat. 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. Another cause for concern is the golden mussels’ prolific reproduction capabilities. They reproduce similarly to zebra and quagga mussels, producing thousands of free-floating larvae known as veligers that move freely in the water column until settling on a hard surface to grow.

Aquatic Nuisance Species
Aquatic Nuisance Species (ANS) are aquatic plants and animals that invade lakes, reservoirs, rivers and streams. ​Aquatic Nuisance Species can also include fish pathogens and diseases, such as viral hemorrhagic septicemia (VHS) or whirling disease.  Colorado has taken the threat of these invasive species seriously through the development of the Colorado Aquatic Nuisance Species Act and the Colorado Parks and Wildlife Aquatic Nuisance Species Program. 

Learn more about the aquatic species threatening Colorado waters and CPW’s ANS program.