The Spread of Quagga Mussels
The quagga mussel has appeared in lakes Mead, Havasu and Mohave in Arizona. Now, managers at Lake Powell are doing whatever they can to keep the mussels out. If they do show up in the lake, they could cause boat motors to overheat and docks and the shoreline to be littered with sharp shells.
The species can populate to a density of hundreds of thousands per square yard and deprive fish and other organisms of food. There is no effective means of killing the organisms across a lake the size of Powell.
If the mussel gets to Lake Powell it will be by one of the 100,000 boats that visit the lake every year. If one of those boats has been exposed to the mussel and not been washed in hot or high-pressure water afterwards, then the mussel has a good chance of establishing in the lake. Lake Mead is attempting to wash houseboats and boats moored for in the lake to prevent the spread elsewhere. Lake Mead sees up to 5,000 boats in one weekend.
Quagga mussels were introduced to the Great Lakes region in the ballast of ships from Eastern Europe and the Ukraine. They can plug pipes up to 12 inches in diameter, and restrict flow in larger pipes.