Prolific alien invaders’ threaten waters in the West

Zebra mussels are now in the upper Colorado River system, and the minuscule mollusks can wreak massive damage.

Washington Post | Karin Brulliard

LOMA, Colo. — Water is a driving force in the American West, and today it’s at risk more than ever. Not just from overuse, not just from megadrought, but from minuscule invaders that pose a nearly unstoppable threat to the region’s rivers, lakes, dams and reservoirs.

Typically smaller than a nickel, zebra and quagga mussels have spread across Europe and the eastern United States, doing billions of dollars in damage by clogging infrastructure, wreaking havoc on ecosystems and eating food on which native fish and other animals rely.