The zebra mussel larvae, an invasive freshwater species native to southern Russia and Ukraine, have been discovered in the Colorado River, posing a threat to the local ecosystem.
The Colorado Parks and Wildlife (CPW) agency reported the detection of zebra mussel larvae (Dreissena polymorpha) in the waters of the Colorado River, as reported by Newsweek on July 22. This discovery has raised concerns among conservationists due to its potential significant impact on native fish populations, especially in areas with slow-moving water.
Zebra mussel larvae were discovered by the Colorado Parks and Wildlife (CPW) agency in the Colorado River. (Photo: CPW)
The zebra mussel is a freshwater mussel that inhabits lakes in southern Russia and Ukraine. They arrived in the Great Lakes region (five major lakes along the US-Canada border) in the 1980s via international shipping. This species is small, typically less than 5 cm in length, and has distinctive striped shells resembling the stripes of a zebra. They reproduce rapidly, with females capable of laying up to one million eggs each year, allowing them to quickly invade new areas.
Due to competition for food and space with native species, zebra mussels are harmful to the ecosystem. They are filter feeders, extracting plankton from the water, which disrupts the local ecosystem. In the Colorado River, native fish may starve as plankton becomes a food source monopolized by the mussels.
“Zebra mussels pose an extremely high ecological risk to the state of Colorado. Their presence in the Colorado River could negatively affect native fish populations due to their filtering strategy, which targets essential prey in the water like plankton. Sections of the Colorado River with slower flows, such as eddies and stagnant areas, are particularly susceptible to invasion,” stated CPW.
Zebra mussels have a distinctive striped pattern resembling that of a zebra. (Photo: iStock)
Experts found only one zebra mussel larva in two water samples from the river and did not detect any adult mussels. This means that the sampling locations are considered “suspected of zebra mussel presence.” CPW will conduct further sampling to determine if the river is indeed “positive” for this species.
The presence of zebra mussels in Colorado would also significantly affect infrastructure designed to divert water from the river. The mussels attach to surfaces using byssal threads, making them very difficult to remove. These threads can clog water infrastructure, harming the river, especially since the mussels reproduce so rapidly.
“This new challenging discovery will not only have ecological and economic impacts on the Grand Valley but could also affect the entire state. CPW is committed to collaborating with all partners to better understand the scope of this discovery and the next steps to protect natural resources and infrastructure,” said Jeff Davis, director of CPW.
