Quagga mussel (Dreissena bugensis)

Invasive characteristics

Byssal threads allow adult quagga mussels to hitch a ride on any solid surface, including aquatic plants, watercraft, aquatic equipment, and gear. Once attached, they can survive out of the water for up to a month in cool, damp conditions.  

Microscopic larvae can be transported in anything that holds water including bilges, live wells, motor cooling systems and other water systems.

Free from predators and conditions that restrict their growth and spread in their native range, quagga mussels attach to all available surfaces, forming dense carpets that smother native species leading to habitat loss. Loss of aquatic plants leads to increased water transparency, increasing water temperature and encourages aquatic weed growth. Loss of habitat leads to declines in native species populations. 

Quagga mussels bioaccumulate pollutants and toxins. Animals that eat the mussels then spread toxins through the food chain to animals that eat them, eventually making fish and wildlife unsafe for human consumption. They also lead to increases in botulism causing bacteria, a serious neurotoxin and risk to human health.

Once introduced to freshwater bodies in the U.S., quagga mussels have proven nearly impossible to eradicate. The best way to avoid the catastrophic threats posed by quagga mussels is to prevent them from establishing in Washington’s waters. 

Prevention

Once introduced to freshwater bodies in the U.S., quagga mussels have proven nearly impossible to eradicate. The best way to avoid the catastrophic threats posed by quagga mussels is to prevent them from establishing in Washington’s waters. 

While WDFW monitors waterbodies statewide each year for zebra mussels and prepares to address a potential detection, anyone who recreates or works on Washington’s waters can help prevent invasive mussels from reaching our waters. 

Overland transportation of invasive mussels on contaminated gear, equipment, and watercraft is preventable by remembering to Clean, Drain, Dry and stopping at all mandatory watercraft inspection stations. Prevent contaminated aquarium plants from introducing invasive mussels to our waters by properly disposing of them. 

If you suspect your gear, equipment, watercraft, or aquarium plants may be carrying invasive mussels, take a photo and report it online using the Washington Invasives online reporting form or download the app. More information on preventing the spread of aquatic invasive species like zebra mussels can be found on the prevention webpage.