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Health, Science & Environment

Invasive Quagga Mussel Could Cost State Millions

Brian Grimmett
Quagga mussels cover rocks a few feet under the water in the Castle Rock Cut at Lake Powell

The Utah Division of Wildlife Resources is fighting an uphill battle against a fast spreading, invasive species known as the quagga mussel. The DWR is doing what it can to stop its spread, but there are potentially disastrous consequences if they don’t.

The first quagga mussels in Utah showed up in Lake Powell on the Utah-Arizona border in the spring of 2013. An infected boat that hadn’t been properly drained or cleaned likely put them there. And in just two short years the mussels have already become a major problem near the Wahwheap Marina and the Glen Canyon Dam.

“In this one half a mile long channel there’s well over a million mussels in just two years. That’s the problem with them. They’re just so prolific. Each one of those individual mussels can produce one million offspring each year,” said Wayne Gustaveson.

Wayne Gustaveson
Credit Brian
DWR Biologist Wayne Gustaveson has been working at Lake Powell for almost 40 years.

He’s been working at Lake Powell as a biologist for the Utah Division of Wildlife Resources for almost 40 years. He took me out on a small flat-bottomed boat to go and see how bad it has already become in the Castle Rock Cut.

At first, it’s hard to tell if what I see is actually a quagga mussel. A quagga’s shell is mostly black and they’re only about the size of a fingernail. But soon, I realize I can’t see one, because I’m already looking at thousands of them covering the walls and cracks of the canyon.

“This little guy can suck in one liter of water per day," said Gustaveson. "And he’s got a billion buddies. So a billion liters of water every day siphoned through mussels is going to change the whole process of how the lake actually works.”

Credit Brian Grimmett
Quagga mussels are mostly black, and about the size of a fingernail.

When the mussels siphon the water they remove large amounts of microscopic phytoplankton, which essentially eliminates the food source of several species of fish.

The invasive species originates from Ukraine and was first found in the United States in the Great Lakes. They’ve now spread to the entire Mississippi river basin, and hundreds of lakes across the U.S.

Since quagga mussels established themselves in the Great Lakes, they’ve already contributed to the decline of several species of fish. Gustaveson fears the same will happen in Lake Powell.

“So if we’re on that same time frame in Lake Powell. We've had them since 2012, by 2024 stripped bass and threadfin shad might be gone," he said. "Yeah, that’s serious.”

And it’s not just damage to the ecosystem that state officials are worried about.

“If we were to get quagga mussels in the Central Utah Project, which is the network of reservoirs and pipelines and canals that feeds water into the Wasatch front for us to be able to drink, it would cost a minimum of about $22 million dollars a year to clean up,” said Jordan Nielson, Utah aquatic invasive species program coordinator.

"If we were to get quagga mussels in the Central Utah would cost a minimum of about $22 million dollars a year to clean up." - Jordan Nielson

He says that nightmare scenario might have already happened.

At the end of last year, DWR biologists found evidence of juvenile quagga mussels, or veligers, in Deer Creek Reservoir in Provo Canyon. But finding juvenile mussels doesn’t mean that an adult population is becoming established.

To determine if the scare is real, Nielson and his team of biologists will monitor the reservoir for the next three years. I went with Nielson on a recent trip to Deer Creek to watch as they took water samples and attached small pieces of vinyl fencing to buoys.

“What it does is gives it a lot of surface area for anything to settle on," he explained. "So if there are veligers floating around in the water the more surface area we can have under there, the more likely we are to find something that actually settles out and becomes an adult.”

To prevent the quagga mussel from spreading even more, boaters on Lake Powell and Deer Creek are now required to clean, drain, and dry their boats before leaving. Boaters are also required to let their boat dry for at least seven days before putting it back into another lake. Nielson says boaters are an important part of the plan.

“They can do more work and a better job than our technicians on the ramp if they just do it themselves.”

The state also offers free professional hot water decontamination. Boaters who chose not to clean their boats can be charged with a misdemeanor and receive a fine up to $2,500.

Credit Brian Grimmett
DWR Conservation Officers stop vehicles towing boats on Highway 89 outside of Big Water to check for quagga mussels.

DWR officials are also increasing the use of enforcement measures, like this recent checkpoint that took place on highway 89 near Big Water.

“Education is the key here," said Lt. Scott Dalebout. "If we can just get everybody on board, literally, and try to spread the message, these critters may eventually take over, but the longer we can put it off the more millions of dollars we can save.”

Dalebout is a conservation officer with the Division of Wildlife Resources.

“The majority of boaters are great. They understand what we’re doing," he said. "They’ve very supportive. They know it’s a very, very difficult task but they’ve actually thanked us. Every once in a while we’ll get someone who’s annoyed, they just don’t want to be delayed, and that’s fine.”

Credit Brian Grimmett
Quagga mussels in Lake Powell

“Really what it takes is for boaters to buy in and understand that they’re not the problem. They’re the solution," said Jordan Nielson. "We can put all the technicians in the world out there; we’re still not going to catch everybody. So, we really need people to just understand that they can help us.”

But Nielson also admits that with more than 100,000 boat launches a year at Lake Powell alone, keeping the quagga mussel from spreading won’t be easy.

“They are going to move around," he said. "We’re going to see them move around. Hopefully we don’t see them move around in Utah. Hopefully we’ve built a good enough wall around where mussels are that we’ll never see them in another place here.”

For now, Nielson and his team of DWR biologists can only continue to monitor and wait, to see if their efforts will make a difference. 

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