Species and Origin: Quagga mussels are native to the Dneiper River drainage of Ukraine and most likely they arrived in the ballast water of ocean going ships. The quagga mussel was first sighted in the Great Lakes in September 1989.
Impacts: Quagga are prodigious water filterers, thus removing substantial amounts of phytoplankton from the water and altering the food web. Like zebra mussels, they clog water intake pipes and underwater screens and can damage boats, power plants, and harbors. Both quagga and zebra mussels also destroy the native mussel population.
Means of spread: Quagga mussels attach themselves to boat hulls and trailers and can be transported this way.