Photo courtesy of Don Schloesser, Great Lakes Science Center, National Biological Services

Quagga Mussels

Discovered in January 2007 at Lake Mead, non-native quagga mussels have caused quite a stir in Southern Nevada. Similar to its cousin, the zebra mussel, the quagga mussel is described by scientists as one of the most invasive species worldwide and can live at depths of nearly 400 feet.

Sometimes referred to as "biological pollution," species like the quagga mussel can cause irreversible harm to the environment. Quaggas pose a serious threat to the ecosystem as well as the water intake system located at Lake Mead.

Quaggas filter up to a liter of water per day, impacting the food chain of native fish and other aquatic wildlife by decreasing the food supply. They also clog and restrict water flow in pipes of all sizes, requiring costly upkeep and repairs. To make matters worse, they multiply at an alarming rate. A single female quagga can produce more than one million eggs in a spawning season.

Quaggas in Lake Mead

Initially discovered in Boulder Basin, the mussels also are in the Lake Mead fish hatchery and Callville Bay, according to the Nevada Department of Wildlife.

The Southern Nevada Water Authority (SNWA) has established a monitoring program that includes regular diver inspections of its facilities. To date, no adult quaggas have been found at SNWA treatment facilities. However, veligers (quagga larvae) have been found in the raw water as it comes into the plant. It should be noted that SNWA's water treatment processes destroy all quaggas before they can get into the drinking water system.

Preventing infestation

Perhaps the best way to control the quagga mussel is through prevention. The quagga moves from one body of water to another in bait buckets or bilge water or by attaching themselves to boat hulls and trailers.

In addition, a chemical treatment system is already in place on Intake 2, and SNWA treatment managers are evaluating the options for treatment on Intake 1 to control the species.

With the goal of preventing the further spread of the quagga, agencies across the West are working to establish protocols for cleaning boats and other marine equipment and increase public awareness.

On the national front, a bill was recently introduced in the U.S. House of Representatives by Rep. Jon Porter of Nevada, giving the National Park Service the authority to combat invasive species like the quagga mussel beyond park borders.