Quagga and zebra mussels have devastated fishing waters, plugged water delivery systems and ruined boats all across the nation.

But those things haven’t happened in Utah. How come?

Counterattack

In 2007, the Utah Legislature, the Division of Wildlife Resources and several statewide partners launched a massive effort to keep mussels from doing the same things in Utah.

Larry Dalton, aquatic invasive species coordinator for the DWR, says so far the effort has been successful.

Since 2007, evidence that quagga or zebra mussels might be in Utah has been found in eight waters. However, as of January 2012, only one of those waters is still classified as possibly having mussels in it:

• Lake Powell has not shown any evidence of quagga or zebra mussels since inconclusive evidence that mussels might be in the reservoir was found in 2007.
• Inconclusive evidence that mussels might be in Joe’s Valley Reservoir, Huntington North Reservoir, Pelican Lake and Midview Reservoir was found in 2008. But DNA testing failed to confirm that what appeared to be juvenile mussels also called veligers were actually quagga or zebra mussels.Since 2008, no DNA evidence or evidence of adult mussels or veligers has been found in any of these waters.

  “This is very good news for the state of Utah,” Dalton says.

• In 2008, DNA testing did confirm that juvenile mussels were present in Electric Lake and Red Fleet Reservoir. But no evidence has been found since that time.”We’ll watch these waters closely to make sure the mussels haven’t gained a foothold,” Dalton says.
• Sand Hollow Reservoir in southern Utah is the only water in Utah that’s still classified as having mussels in it.An adult quagga mussel was found in the reservoir in 2010. And recent DNA tests of the water indicate mussels might still be in the reservoir.

  “Fortunately,” Dalton says,” no more mussels or their veligers have been found since the initial discovery in spring 2010. We’ll monitor Sand Hollow closely for at least three more years.”

Keys to success

So why haven’t mussels gained a foothold in Utah?

Dalton credits the statewide effort that started in 2007.

“That effort has allowed us to decontaminate boats, including boats that have mussels attached to their hulls,” he says.

He says the effort has also allowed biologists to detect the presence of mussels early in a body of water. “If we find mussels quick enough,” he says, “we can take measures that will lessen the chance that more mussels are introduced to the water.

“If we can prevent additional mussels from being introduced to the water, the mussel population that’s already in the water may die off.”

Despite the good news, Dalton says the fight continues. “We can’t afford to let our guard down,” he says. “If we let our guard down, the results to the state of Utah could be catastrophic.”

Efforts since 2007

When invasive mussels were discovered in neighboring states in 2007, Utah’s natural resource managers immediately bolstered their resources to fight back.

The National Park Service at Lake Powell and the DWR, aided by the Utah Legislature and many statewide partners, put a small army of boat inspectors on the ground at boat ramps across Utah.

(Boaters in Utah can’t launch their boats unless the boats have been properly decontaminated to kill any mussels that might have attached themselves to the boat.)

Laws were also changed to make it easier for DWR personnel to check boats. And water sampling to monitor for the presence of mussels began in waters across the state.

Those efforts, coupled with a significant outreach program that informed boaters about the risks invasive mussels pose to Utah, represent the core of the fight.

“Boaters listened,” Dalton says. “They joined the effort to protect Utah’s complicated water delivery structure, the state’s world-class, water-based outdoor recreation areas and the state’s economically valuable sport fisheries.”

Dalton says his surveys show that more than 95 percent of the state’s boaters understand the risks quagga and zebra mussels pose to the state. “That explains why more than 80 percent of the boaters say they always decontaminate their boats and other wet equipment after every use,” he says.

“Certainly, Utah’s water managers understand the risk, too, since they’re helping with the fight.”

Even though news from the mussel front is good, Dalton says Utah cannot give up the fight. “Utah cannot afford a widespread infestation of quagga or zebra mussels,” he says. “Not today. Not ever.”

Why the concern?

The following are reasons why Utahns should be concerned about quagga and zebra mussels:

• Mussels can plug water lines, even very large diameter ones.Dalton says widespread infestation by quagga or zebra mussels could cost Utahns more than $15 million every year to maintain Utah’s water delivery systems. “That cost would likely be passed on to every citizen in the form of higher utility bills,” he says.
• Mussels remove plankton from the water column, the same plankton that support Utah’s sport fish and native fish. The mussels could devastate fisheries in Utah.
• Mussels can damage your boat by attaching themselves to your boat’s hull and fouling the boat’s engine cooling system.
• When mussels die in large numbers, they stink. And their sharp shells can cut your feet as you walk along the beaches where the mussels died.