Federal and state officials are renewing warnings to boaters about aquatic invasive mussels. The tiny hitchhikers threaten native marine life.
Full grown quagga and zebra mussels are the size of a dime, or a human fingernail. They've infested lakes in Southern California, Arizona, Nevada and Colorado.
Water agencies spend millions of dollars trying to eradicate and control them. When the mussels number in the hundreds of thousands they can clog pumps and water systems.
A larger, prolonged infestation in the Great Lakes region has cost government there upward of a billion dollars. Quagga and zebra mussels also nudge aside native sea life and change the aquatic food web.
Federal and state officials are asking California boaters to inspect and wash down all exposed surfaces, remove plants from boats and trailers, clean and dry bait buckets, and let boats fully dry out before they move from one body of water to another.
The state lacks the money it would need to inspect watercraft everywhere people go boating. Until then, officials say, watchful boaters are the primary line of defense.