(reverent orchestral music) - I'm Starla Sampaco in the Crosscut KCTS 9 newsroom.

(soft ambient music) In February, a Petco store employee in Ballard find tiny fingernail-size zebra mussels nestled in imported aquarium plants known as moss balls.

Alarm bells went off all over the state, as an invasion of zebra mussels here would be an environmental nightmare, according to biologists.

Benign in their Black Sea ecosystem, they are disastrous everywhere else.

The rapid-spawning shellfish have infested every watershed in the lower 48 states except the Columbia River Basin.

Zebra mussels create havoc by weaving colonies out of themselves in such dense clusters that they physically block key water passageways, which has drastic implications for hydropower, irrigation, salmon passage, and drinking water.

Wildlife officials are now tracing moss ball sales and conducting zebra mussel recovery drills.

I'm Starla Sampaco.

If you have concerns about your recent purchase of aquarium plants, go to crosscut.com for more information.

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