By Michael Booth | Colorado Sun
New rounds of samples for the voracious creatures keep turning up positive, complicating containment
The Colorado River is now officially “positive” for invasive zebra mussels in the latest failure of containment for the voracious species, after three new samples came up with larvae July 3, from between Glenwood Springs and Silt.
The main stem Colorado River discoveries piled on top of a confirmed “large number” of adult zebra mussels in a private body of water in western Eagle County, and two more positive larvae tests, at Highline Lake and Mack Mesa Lake, both near the Utah border, Colorado Parks and Wildlife officials said Wednesday. Sampling was redoubled throughout June after tests found a single zebra mussel larvae, or veliger, in the Colorado River from a June 9 collection.
It’s the second year in a row veligers are being discovered in the West’s key river channel through Colorado, and now CPW officials are also dealing with a full-blown adult zebra mussel invasion in the privately owned Eagle County water. A year ago, researchers called the first discovery of larvae in the main stem river “devastating.”
Wildlife officials are trying to stay positive this time around, though zebra mussels have eaten their way through other states with a multiplication rate of a million eggs per female mussel per year, and 700,000 adult mussels massing in one square meter. They can eat up all the food sources needed by native wildlife, and clog and erode river and lake infrastructure.
“Not great news,” acknowledged regional CPW spokesperson Rachael Gonzales. “But from the very beginning, it was never great news. But these little steps are crucial in helping us figure out, OK, where do we go next? What do we do next?”
For now, “next” means even more sampling up and down the river, while considering options for how to eradicate the adult mussels in the private Eagle County water body, Gonzales said. The state continues to emphasize boater and floater education, with boat inspections and cleanouts a key to preventing the spread of mussels that can survive relatively long periods out of the water.