Questions about Quagga Mussels

What Is A Quagga Mussel?

Quagga mussels are a type of mollusk, a small (usually less than 1-inch) clam-like shellfish that lives in fresh water lakes and streams.

Why Are These Animals "In The News"?

Quagga mussels are a non-native species that can harm the ecosystems of bodies of water they invade. Because they reproduce very rapidly, populations of quagga can quickly grow once they are introduced into new lakes or streams. Like many mollusks, they cling to hard surfaces and filter their food out of the water. As they grow in number, they can foul water with their waste, clog pipes and damage water treatment and power plant facilities. Government agencies and private entities in the United States have spent billions of dollars to address the impact of non-native mussels since they were first detected in the country.

How Do They Harm Native Ecosystems?

Quagga mussels compete with native water dwellers for food, breed quickly, and change the physical and chemical nature of the water they invade. By filtering large amounts of water, the allow sunlight to penetrate deeper, which can alter the type of aquatic plants that live in the area. Filter-feeding quagga also concentrate water pollution in their waste, which can then be passed up the food chain and harm native fish and fish predators.

Have They Been Found In Arizona?

Yes, in 2007, Quagga mussels were detected in Lake Mead, perhaps introduced as "hitchhikers" on a recreational boat. Since then, they have also been found in Lake Havasu and Lake Mohave, and in the CAP canal system, Lake Pleasant, and in some of the SRP canal system.

How Did Quagga Mussels Get Here?

The mollusks were first detected in the Great Lakes in the 1980s, probably imported from their native Eastern Europe in the ballast water of a trans-Atlantic cargo ship. Since that time, they have been found in at least 15 states and 2 Canadian Provinces.

What Is CAP Doing To Address Quagga Mussels?

CAP is partnering with a number of federal, state and local agencies and quagga mussel experts to determine how best to reduce quagga populations without affecting other water dwellers. CAP is currently involved in an extensive monitoring program to determine where the mussels have settled and the water quality characteristics that attract or deter quagga from colonizing new areas. For instance, the relative acidity (pH) of the water may affect the behavior of the quagga in their free-swimming larval form (veligers).

Fortunately, populations of both larval and adult quagga quickly drop as the Colorado River water flows through the CAP system. Our monitoring and research program will evaluate whether the amount of sediment in the CAP water, the type and amount of algae, the temperature of the water, or some combination of these, are damaging to quagga mussels. Determining what characteristics of the CAP water or system kills the mussels may lead to future CAP treatment strategies.  The research may also determine that active treatment for mussel infestations may not be necessary, saving CAP water users significant costs.

 What Can I Do To Help?

Education is a key element to stopping the spread of quagga mussels. Boats must be thoroughly examined and cleaned, drained, and completely dry before moving to a new body of water. Many federal and state wildlife departments require certification or other proof that the boat is "mussel-free." Some even impose fines for boaters who do not follow these procedures.

Where Can I Get More Information On Quagga Mussels?

There are many State and Federal sources of information on quagga mussels. The Arizona Game and Fish Department web site, http://www.azgfd.gov/, has information about the lakes in our state. A "Google" search will help you find other information about quaggas.

For more details about the CAP Quagga Program, contact Communications Representative Mitch Basefsky at 520-682-9077 or mbasefsky@cap-az.com.