Invasive mussel threat on the rise at Ruedi, other Colorado reservoirs |

Invasive mussel threat on the rise at Ruedi, other Colorado reservoirs


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Ruedi Reservoir and other Colorado waterways are facing an increased threat of infestation by invasive mussels that could interfere with the function of dams and irrigation systems and harm native fish, according to state and local authorities.

It’s not an issue that can be taken lightly, Colorado Parks and Wildlife says, because operators of reservoirs might be forced to close them to boating to protect their infrastructure.

At a statewide level, inspectors have intercepted 51 boats infested with mussels this year — equaling the total for all of last year.

The numbers are also up at Ruedi Reservoir where inspectors intercepted four boats in June and decontaminated them, according to April Long, executive director of the Ruedi Water and Power Authority. No mussels were detected at Ruedi Reservoir prior to 2018, when two craft were intercepted and decontaminated. Once clean, they are allowed to enter the water.

“The numbers show this is an increasing threat.” — April Long, Ruedi Water and Power Authority

“The numbers show this is an increasing threat,” Long said.

All four boats intercepted this year came from Ruedi from Lake Powell, which has been infested with mussels for several years, according to Long.

In all cases, the boats were carrying Quagga Mussels, a small shellfish native to Eurasia that was inadvertently transported to North America by cargo vessels in the late 1980s.

Long said the shellfish pose a threat to all infrastructure at Ruedi — particularly the mechanical system used at the power and water authority’s hydroelectric plant beneath the dam and the mechanism the U.S. Bureau of Reclamation uses to control flows.

The shellfish reproduce rapidly and attach themselves to any surface in still water. They do not pose a threat in rivers and other running water, according to CPW officials. However, they could ruin the fishing at Ruedi. They consume plankton and disrupt the food web. They out-compete sport fish and native fish, according to the wildlife service.

Boats are supposed to be inspected when they leave Lake Powell, but inspection stations are regularly overwhelmed so some boat owners sneak through. Boaters are also supposed to clear, drain and dry their craft in between uses but that doesn’t always happen. Mussels can also be found on paddleboards and canoes that have been in Powell. That poses an even greater danger that they could end up in Colorado waterways where inspections aren’t undertaken.

At Ruedi, the aquatic nuisance species program began in 2008 but was not fully implemented until last year, when enough funding was secured to provide inspectors at the main ramp for extended hours.

The concessionaire that runs the campgrounds at Ruedi — Rocky Mountain Recreation Co. — runs the inspection program under contract to Ruedi Water and Power Authority. Several parties contribute funds to the program.

All boats entering and leaving the reservoir must be inspected. The main boat ramp is open from 6 a.m. to 10 p.m. during July, which is the busiest month at Ruedi. The ramp is closed to all boat traffic when inspectors are not on site.

“We’ve had our lock broken this year and it’s happened in the past,” Long said.

She thinks it is more a case of people wanting access during off-hours rather than opposition to the inspection program. Nevertheless, scofflaws could end up getting Ruedi infested with mussels, she said.

Colorado Parks and Wildlife said this would be a record for the number of boats intercepted with mussels statewide. Since the invasive species became an issue, more than 200 vessels with confirmed mussel infestations have been intercepted and decontaminated.