Zebra and quagga mussels have already invaded waterways in many eastern US states since they were first spotted in the late 1980s. They have destroyed pipelines, water pumps, power plant intakes, and other underwater structures they cling to, and are wreaking havoc on native underwater inhabitants. They were discovered in the West for the first time in several locations in 2007.
The mussels' tiny progeny can spread by attaching themselves to boats, wading boots, nets, and other objects that are then used in other waters. A variety of preventive strategies are under urgent consideration. The mussels are considered "horribly difficult" to eradicate once established.
Researchers from Oregon State Univ. and EPA predict that the mussels may eventually spread to at least 30 states. Their work, published online Dec. 3, 2007, in the journal Frontiers in Ecology and the Environment, is built on the premise that the mussels are most viable in waters above a certain calcium concentration.
- Study: "A calcium-based invasion risk assessment for zebra and quagga mussels" (abstract ). A map of watersheds and states at risk is here.  Lead author: Thom Whittier,  541-754-4455.
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