AUSTIN, Texas (CBSDFW.COM/AP) — Experts say fifteen Texas lakes are infested with invasive zebra mussels, and the Texas Parks and Wildlife Department is urging thousands of boaters to clean, drain and dry their watercraft after use ahead of Memorial Day weekend.

“Memorial Day weekend is the unofficial kick-off to boating season in Texas, and while we want everyone to have a great time we also want them to avoid giving free rides to invasive species when they travel to new lakes,” Brian Van Zee of the TPWD said. “The best way to help keep Texas lakes fun for everyone and prevent the spread of destructive invasive species is to clean, drain and dry your boats and equipment — every time.”

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Zebra mussels (Photo by Kilian FICHOU/AFP/Getty Images)

Texas bars transport of prohibited invasive species, and violators can face fines of up to $500.

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The updated list includes zebra mussels detected more than once at Lake Walter E. Long, Lake Granger and Lake Dunlap. Zebra mussels or larvae have been confirmed at least once at Lake Placid.

Zebra mussels can clog pipes, damage boat motors and affect other aquatic life.

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Some Austin residents recently complained about stinky tap water . Rotting zebra mussels were discovered in a turned-off water plant pipe.