How serious is the threat of invasive mussels such as zebra or quagga mussels?

The zebra mussel and its close cousin, the quagga mussel, have become the most serious non-native biofouling pests to be introduced into North American fresh waters. An infestation causes mussel colonies to form on all surfaces including boats, engines, buoys, pipes, water intakes, ladders, beaches, native shellfish, aquatic vegetation, adversely affecting the ecosystem and anyone who uses the lakes.

The most serious measurable economic impacts are suffered by water districts and other users of lake water who may have increased maintenance costs due to plugged water pipes, intake screens, and possible damage to pumps and other equipment. It even impacts citizens who don’t use the lakes through increased costs for drinking water and food prices passed along to consumers by the water and agriculture industries brought on by their increased costs in maintenance and equipment repair. It impacts the local fisheries, and in some lakes, has caused a collapse in the populations of sport fish.

These mussels have the ability to tolerate a wide range of conditions and are extremely adaptable. Once they have infected a water body, they cannot be eradicated. They have no predators native to the US. They cannot be prevented from spreading into downstream waters.

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