The propeller of a cabin cruiser boat covered by quagga mussels is inspected at Highline Lake State Park. An inspection can take as little as 10 minutes if a boat is clean and dry, but if it has to be decontaminated, it can take anywhere from an hour to a couple of days, depending on the level of contamination.

Colorado Parks and Wildlife officials are sounding the alarm about the high number of mussel-infested boats being detected this year during inspections on state waters — a number that already ties last year's record total.

Fifty-one boats have been found to have the invasive aquatic animals on them only halfway into this year's boating season, the agency says. That's how many were detected during inspections during all of last year, an amount that itself had doubled the number the year before.

"I am just being completely overrun by mussel-infested boats," Robert Walters, CPW's assistant manager for the aquatic nuisance species program, said in a news release.

CPW says the detections are occurring at waters all around the state, and mostly involve boats coming out of Lake Powell.

Colorado waters continue to be mussel-free thanks to what CPW says is a robust inspection program.

The creatures are of concern because they clog infrastructure such as dams, outlet structures and distribution systems delivering water for municipal, agricultural and industrial uses. They also infest boats and damage engines, and in consuming plankton disrupt the food web and outcompete sport and native fish, CPW says.

Alan Martinez, manager of Highline Lake State Park, said two boats have been detected during inspection efforts there so far this year.

CPW says boats are supposed to be inspected when they leave Lake Powell, but inspection stations there are overwhelmed so not all boats are thoroughly inspected. Mussels are even being found on paddleboards and canoes coming out of that reservoir, the agency says.

Martinez said the big issue right now at Powell is a result of its rising water levels. The reservoir is benefiting from runoff from a wet winter and spring in watersheds above it, including in western Colorado. Martinez said mussels typically attach to rocks or something, but many are free-floating now due to the rising waters. They're picked up by inboard motors, attach to things like water toys, and are being found in places such as the compartments where those toys are stored, something inspectors typically don't see, Martinez said.

Since CPW's aquatic nuisance program began in 2008, the agency and other entities have completed nearly 4.5 million boat inspections, more than 90,000 boats have been decontaminated, and more than 200 have had confirmed mussel infestations.

Martinez said most decontamination procedures involve flushing out things such as engines, ballast tanks and anything else that holds water.

He said an issue being seen at some waters this year is people paying a discount to buy boats that have been in Lake Powell, and learning they have mussels attached to them when they are inspected in Colorado.

"You might think you're getting a deal, but ultimately you're bringing mussels into Colorado," Martinez said.

He said what boat buyers might save on the front end of such a deal, they may end up paying on the back end if a boat requires an extensive decontamination process. CPW can seek restitution for its efforts to decontaminate boats.

Martinez said he's working with an area wildlife manager at Lake Dillon to determine how to remove mussels from a boat out of New York state that has a big ballast full of mussels. He said it may require cutting the ballast open to remove them and then patching the hole.

Action by state lawmakers led to a $25 aquatic nuisance fee being charged starting this year for motorized watercraft and sailboats owned by Coloradans to help pay for inspection and decontamination efforts. The fee is $50 for nonresidents. Martinez said those fees help fund about half the program.

CPW encourages boaters coming from Lake Powell to thoroughly inspect their boat and trailers, including lines, anchors, seat cushions, live wells and paddle craft.

More information may be found at

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