The Quagga Quandry – Coming to a Lake Near You? You'd Better Hope Not.

Zebra mussels on bottom of boat.

Zebra mussels attached to the bottom of a boat moored in Oologah Lake, Oklahoma. Photo by David Britton, U.S. Fish & Wildlife Service.

Those tiny mussels called Quaggas cause major problems in lakes and rivers, including those in national parks, and they're spreading across the country. If you think this won't affect you, better think again.

Yes, you've heard about problems with exotic species before, but this one can affect your bottom line along with the environment. So, what's the deal, why should you care, and what can you do about it?

Quagga mussels are relatives of clams and oysters that were introduced into the U.S. from the Ukraine via ballast water discharged from ocean-going ships. They, and their relatives called zebra mussels, were discovered in the Great Lakes in the late 1980s, and have since “hitched rides” to other waters in the United States on boats, trailers and equipment people transport from place to place.

In 2007, quaggas were discovered for the first time in the West in Nevada's Lake Mead and have since been found down the Colorado River in Lake Mojave, Lake Havasu and in various locations in California. In 2008, they were spotted in Colorado, including Grand Lake, Granby, and Shadow Mountain Lakes, adjacent to Rocky Mountain National Park.

Information from Curecanti National Recreation Area, in central Colorado, summarizes why these tiny creatures are causing so much concern.

They grow and reproduce exponentially. A single female can produce up to one million eggs a year. Even if only ten percent of the offspring survive, there would be 10 septillion mussels in the affected waterway at the end of five years.

They have significant economic impact. In the Great Lakes area, increased maintenance costs in water treatment plants, power plant intakes and dams have been in the billions of dollars, and much of the West depends on water from dams and canals.

They clog water infrastructure, impacting water supply and quality. They attach to most underwater structures and can clog water intake pipes, canals, aqueducts and dams. They also degrade water quality and can alter the taste and smell of drinking water. (Researchers have measured foot-thick colonies at the bottom of Lake Erie, and Great Lakes intake canals have held colonies with an incredible three-quarters of a million mussels per square meter.)

They have significant ecological impact. They have the ability to change aquatic ecosystems and native plant and animal communities. The amount of food they eat and the waste they produce had life-altering effects on the ecosystem. They remove large amounts of microscopic plants and animals that form the base of the food chain, leaving little or nothing for native fish and other aquatic species.

They have recreational impact. These mussels encrust docks and boats, and can get into engine cooling systems causing overheating and damage. The weight of attached mussels can sink navigational buoys, breakwaters, docks and small vessels. Their shells are extremely sharp, and can cut feet and hands of swimmers and waders.

They are very difficult to kill. No practical way is currently known to eradicating or even control zebra or quagga mussels in large water bodies and/or connected waterways, so prevention is very important.

They spread very quickly to other water bodies. Mussels can spread to other bodies of water by attaching to boat hulls and anchors, trailers, and fishing equipment. Larvae can be transported in bilge water, ballast water or live bait wells. Mussel larvae also disperse naturally and can be carried by water currents to other lakes or reservoirs downstream or through water diversion.


So, what can be done? The staff at Curecanti National Recreation Area in Colorado has just implemented some changes to try to help, and their actions provide an example of practical steps that can be taken.

As of May 8, 2009, Curecanti began a mandatory program that requires all motorized watercraft launching in the park to be inspected and, if necessary, decontaminated in accordance with procedures set by the Colorado Department of Wildlife.

Vessels that have either been out of Colorado or in waters infested with Zebra and/or Quagga mussels in the past 30 days will not be allowed on Blue Mesa, Morrow Point or Crystal Reservoirs until being dried for a specified period of time or washed at a suitable wash facility. The park website has information on the length of drying required.

Three inspection stations will operate seven days a week at Stevens Creek, Elk Creek and Lake Fork, between 5:30 am and 9:00 pm. Launch ramps will be closed for launching and retrieval between 9:00 pm and 5:30 am. Overnight boaters on the reservoir may camp on their boats or at designated boat-in campgrounds. If you plan to boat at Curecanti, see the park website for more details.

In addition to the mandatory inspection prior to launch ... all motorized watercraft leaving those same three reservoirs will undergo a second inspection to verify the watercraft has been cleaned, drained and dried, and will be sealed and certified.

“The threat of quagga or zebra mussels continues to escalate as waters in and near Colorado report infestations of these invasive aquatic species,” said Superintendent Connie Rudd. “Boaters are reminded that all vessels are required to be certified mussel-free prior to launch."

Rudd knows that everyone won't be happy with the changes, and wants boaters to know that park staff will provide the most efficient service possible.

“We recognize the inconvenience to boaters and understand the need for fast turnaround,” she said. “Our staff will ensure that boats will go through the inspection process as efficiently as possible.” Boaters can assist with the process by arriving at the reservoir with a clean, drained and dry vessel.

“The National Park Service and Colorado Division of Wildlife are committed to the protection of the significant fishery and recreational opportunities at Blue Mesa and ask for the public’s support in preventing mussels from colonizing this and other lakes and reservoirs,” Rudd said.

Efforts such as those at Curecanti, along with education campaigns,can help. A site that provides information about the quagga problem called 100thmeridian.org reports that last month,

Thanks to a conscientious boater, an alert boat mechanic and the protocol set up by the Utah Division of Wildlife Resources ...wildlife officials were able to prevent a boat from launching in Flaming Gorge Reservoir with an aquatic hitchhiker on board: a zebra mussel.

The boat had been recently purchased and transported from a marina at Lake of the Ozarks in Missouri, where zebra mussels are already established.

Similar close calls have been reported on launch ramps at Lake Tahoe, Lake Powell and other major bodies of water in the West.

A major challenge is that the individual mussels are very small, and can easily escape detection unless a thorough inspection and cleaning occurs prior to launching a boat.
The success of efforts to halt the spread of these serious pests is still largely in the hands of individual boaters—but all of us have a stake in the outcome.