Deer Creek Reservoir adds to waters affected by mussels; boat decontamination required

Boat propeller covered in quagga mussels; stock image, not specific to the report attached | St. George News

HEBER CITY — Starting immediately, you must decontaminate your boat before you leave Deer Creek Reservoir in north-central Utah.

The requirement comes after DNA tests conducted by two laboratories found microscopic juvenile quagga mussels — called veligers — in a water sample taken at the reservoir.

Jordan Nielson, aquatic invasive species coordinator for the Division of Wildlife Resources, said the discovery does not mean Deer Creek Reservoir is infested with quagga mussels.

“We’ve found veligers in the past at other waters in Utah,” Nielson said.  “With the exception of Lake Powell, mussel populations never established themselves in the waters where veligers were found.  We’re hoping that will be the case at Deer Creek too.”

Read more: Sand Hollow loses its mussel, and Lake Powell infested with invasive mussels; more related reports below

Nielson said quagga mussels usually do not reproduce in water that’s colder than 50 degrees, so, even if there are adult mussels in the reservoir, there’s currently little risk of the population expanding.  That could change, though, once the water starts to warm in the spring.

One item biologists and water managers are concerned about now is mussels being carried to other waters in or on boats.  That’s why DWR Director Greg Sheehan signed an order on Jan. 15 that requires boats to be decontaminated before leaving Deer Creek State Park.

Upon leaving the park or any infested water in Utah, boaters must do one of two things:

  1. Clean and drain their boat, on their own.  After cleaning and draining, a DWR or Utah State Park technician will place a tag on the boat that indicates when it was cleaned and drained.  The boat will not be allowed to launch at another body of water in Utah until the boat has dried long enough to kill any mussels that might be in or on it. In the winter, boats must dry for at least 30 days.  The drying time can be as little as three days, though, if the temperature the boat is drying in remains below 32 degrees Fahrenheit for at least 72 straight hours. You can see how to do this at the DWR website.
  2. Have their boat professionally decontaminated.  The service is free. You can find the closest unit by visiting the DWR website

A DWR or Utah State Parks technician will determine whether the boat needs to be professionally decontaminated.

“This could be an isolated incident,” Nielson said.  “For example, it’s possible that the veligers made their way to the reservoir in or on a boat that had been on a contaminated water.  We’ll know a lot more after we and our partners conduct further surveys this spring.”

What’s next?

This spring, the DWR and its partners, including Utah State Parks and the Bureau of Reclamation, will take action to learn whether adult quagga mussels are in the reservoir.  That action includes:

  • Collecting and analyzing water samples
  • Sending divers into the reservoir, to search for mussels
  • Placing substrate samplers in the water; adult quaggas attach to these as they move through the water
  • Surveying shorelines

Water from the reservoir flows into the lower Provo River and then into Utah Lake.  Nielson said quagga mussel sampling work has been underway at Utah Lake for years.  “The sampling work will continue in 2015,” he says.

“Reclamation values its partnerships with the Division of Wildlife Resources, State of Utah, and other local water agencies in addressing this difficult invasive species problem,” said Provo Area Office Manager, Wayne Pullan. “We will continue to work together to address this problem and reduce the risk.”

Beginning this spring, Reclamation, Division of Wildlife Resources and Utah State Parks will take action to learn whether adult quagga mussels are in the reservoir, and whether they have spread downstream of Deer Creek Reservoir. The middle Provo River, between Jordanelle and Deer Creek reservoirs, is less at risk because quagga mussels cannot move upstream on their own and would require some other method to be transported upstream.

Why the concern?

If a quagga mussel population establishes itself in Deer Creek Reservoir, residents in Salt Lake County and Utah County, as well as anglers and those who enjoy recreating at the reservoir, have plenty of reasons to be concerned.  For example, quagga mussels can:

  • clog pipes that deliver water; the cost to remove the mussels could cost water users in Salt Lake County and Utah County millions of dollars
  • filter tiny organisms, such as zooplankton, out of the water; fish rely on these organisms for food –  a quagga mussel infestation could affect fish populations in the reservoir, which in turn would affect fishing
  • form massive colonies on popular shoreline areas;  the mussels smell bad and can cut your feet when you walk on them
  • clog your boat’s cooling system; this can cause your boat to overheat, leading to costly repairs

Quagga mussels are a small freshwater bivalve mollusk that grow to around four centimeters in adulthood. They were introduced into the Great Lakes region of the U.S. roughly 30 years ago. Since that time they have steadily spread.

Quagga mussels have the ability to rapidly colonize many surfaces within and on the waters they inhabit. This can lead to issues with clogged or encrusted water intake structures, pipes, and screens. The clogging or encrusting of these structures can lead to substantial increases in operation and maintenance costs. Their shells can litter shorelines and ruin sandy beaches. They compete directly with fish and other aquatic organisms for food.

“It will take time to know for sure, but a recent discovery in Deer Creek Reservoir could end up costing residents in Salt Lake County and Utah County millions of dollars,” said Mark Hadley of DWR. “In addition to affecting fishing and recreation at the reservoir, an established quagga mussel population could clog pipes and water control structures that deliver drinking water to much of the two counties.


  • Quagga photos
  • For more information, visit Utah Division of Wildlife Resources website

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  • Joan January 17, 2015 at 11:51 am

    That is wrong…They do slow down in water colder than 50 degrees but they still reproduce.

  • One for the road January 17, 2015 at 12:04 pm

    Dang Quaggas.!

  • Bobber January 17, 2015 at 1:45 pm

    These cute little things are totally harmless. Build the pipeline 😛

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