Quagga Mussel Threat

Quagga Mussels

Ruby Lake National Wildlife Refuge is facing the threat of Quagga Mussel invasion. These mussels destroy ecosystems, damage your boats, and send toxic pollutants up the food chain into the fish you catch. They have the potential to decimate wildlife populations dependent on the marsh as well as put an end to favorite recreational pastimes including fishing, boating, hunting, wildlife viewing, and wildlife photography.


Quagga mussels are freshwater mollusks resembling small clams. The shells are marked by concentric dark and light brown bands.  Quagga mussels are not native to Nevada or anywhere in North America; they originate from the Ukraine in Eastern Europe.  However, they have managed to hitch a ride on ocean-going ships, and establish themselves in the United States.  Quagga mussels were first detected in the Great Lakes and St. Lawrence Seaway in 1989, and have since spread throughout the eastern and southern regions of the U. S., including the Mississippi River drainage. Link to distribution map (1380KB JPG) 

In 2007, quagga mussels were discovered at Lake Mead, Nevada and Lake Havasu, Arizona.  These detections showed that quagga mussels can jump over 1,000 miles to infect new areas of the West.  Much of the lower Colorado River drainage is now heavily infested with quagga mussels. In May 2011, Lahontan and Rye Patch Reservoirs in northern Nevada became suspect waters for quagga mussels.


Quagga mussels feed by filtering small microscopic plants and animals from the water.   These small plants and animals, called plankton, form the basis of the food chain.  Plankton are typically consumed by a wide variety of aquatic invertebrates and insects, which are themselves very important food sources for many species of fish and birds, including waterfowl, like canvasbacks, and sportfish, such as bass and trout.  

A single adult female quagga mussel can produce over a million eggs each year, and they have the potential to quickly populate and overwhelm a water body.  Their prodigious filtering can collapse the food chain and decimate the amount of food available for birds and fish.  Waters infested by quagga mussels are typically quite clear, but not very productive.  In addition, as quagga mussels filter feed; they may accumulate organic pollutants within their tissues to levels over 300,000 times greater than those in the environment. These pollutants can then be passed up the food chain, if waterfowl or fish consume quagga mussels, or when these pollutants are excreted in the mussel's feces.  The feces can pollute shorelines and recreation areas, and millions of razor-sharp quagga mussel shells can wash-up on once sandy beaches.

Lake Mead Quagga - boatQuagga mussels, unlike their relative the zebra mussel, can attach to both hard and soft surfaces.  They are capable of growing all over boats, water control structures, intake valves, pipes, and other aquatic infrastructure.  At Ruby Lake, they may be capable of attaching to the multitude of bulrush and cattail stems found throughout the marsh.  If they ever become established in the marsh, it will be almost impossible to eradicate the quagga mussels and restore the system to what we have come to know and love.

What You Can Do 

Adult quagga mussels and their free-swimming microscopic larvae, which are called veligers, are pretty tough.  They can survive out-of-the-water for up to five days, and even longer if they are in a wet area.  This means they can be transported on boating and fishing equipment from one lake or reservoir to another.  Frequently, fishing or ski boats have damp areas in the bilge, dark recesses, or under piles of life jackets or other gear that can harbor mussels or veligers.  Plus, outboard motors use lake water for cooling, by drawing water up into the engine, circulating it, and discharging water back into the lake.  When you pull your boat out of the water some water is left inside the engine, and if the boat is transported to a new water body, the left over water could accidentally introduce quagga mussels.

Boaters should:

1. Drain the water from your boat motor, live well, and bilge on land before leaving the immediate area of the water you are on.

2.  Remove all visible mussels and check for rough or gritty spots.  These may be young mussels that are hard to see.

3.  Flush the boat hull, motor, bilges and other equipment with hot soapy water.

4.  Clean all boat, fishing, and skiing equipment with a 5% bleach solution or water hotter than 104 degrees.

5.  Air-Dry your boat, personal watercraft and other equipment for at least five days before moving to a new body of water.

6.  Do not re-use bait in a new body of water.

Fortunately, Ruby Lake NWR already has a high-tech power washing system that can generate the high temperatures (104 º F) needed to kill quagga mussels.  In 2012, the Refuge implemented a voluntary inspection and cleaning program. If your boat has been in the water anywhere outside Ruby Valley, we ask that you stop by the Headquarters Office for a free inspection and consultation.  If needed, we will power wash your boat - no charge.

Thanks for taking the time to learn about quagga mussels.  There are other potential invaders, such as zebra mussels and New Zealand mud snails, which could negatively impact Ruby Lake.  Luckily, the same measures listed above for quagga mussels are also effective on these other aquatic threats.