LAKE COUNTY, Calif. – State and local agencies battling the spread of invasive quagga and zebra mussels are asking boaters to be especially vigilant over the three-day Labor Day weekend.

Quagga and zebra mussels are non-native freshwater mussels that multiply quickly and can encrust watercraft and infrastructure. They also can compete for food with more desirable species

The mussels spread easily from infested bodies of water by attaching to nearly anything that has been in an infested waterbody, or by being transferred in water held in boat engines, bilges, live-wells or buckets.

Boaters are asked to clean, drain and dry motorized and non-motorized watercraft and any equipment that comes into contact with lakes, rivers or other waterways both before and after boating.

Anyone who launches a vessel into any body of water in the state is subject to watercraft inspections.

In Lake County, all registered water vessels must be screened before they are launched in local waters. Failure to comply is a misdemeanor that brings with it a potential $1,000 fine.

The screening requirements in Lake County do not apply to canoes, kayaks, car-top boats, float tubes, rafts, wind surfers/boards, boogey boards, nonmotorized paddle boats, and nonmotorized sail boats that are 8 feet or less in length.

County ordinance bans the disposal of live bait and any liquid that contains or has contained live bait into Lake County water bodies.

More about Lake County rules can be found at http://www.nomussels.com/ .

To ensure that watercraft is clean, drained and dry, many local agencies are conducting boat inspections.

DFG has posted the list of these inspections on its Web site, www.dfg.ca.gov/invasives/quaggamussel , along with information about invasive mussels and what people can do to help prevent their spread in California.

Boaters should call ahead to check for restrictions prior to visiting their destination.

To prevent the spread of invasive mussels and pass inspections, boaters should inspect all exposed surfaces, remove all plants and organisms, drain all water, including that contained in lower outboard units, live-wells and bait buckets, and allow the watercraft to thoroughly dry before launching.

Watercraft should be kept dry for at least five days in warm weather and up to 30 days in cool weather between launches in different bodies of fresh water. These measures are vital to safeguard California waterways.

DFG also has developed a short video demonstrating the ease of implementing the clean, drain and dry prevention method, which can be seen above.

In addition, a detailed guide to cleaning vessels to prevent the spread of mussels is available on the Department of Boating and Waterways Web site at www.nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=4957 .

Travelers also are advised to be prepared for inspections at California Department of Food and Agriculture Border Protection Stations.

Inspections may include not only a check of boats and personal watercraft, but also of trailers and onboard items. Contaminated vessels and equipment are subject to quarantine or impoundment.

Quagga mussels were first detected in the Colorado River system in January 2007 and were later found in San Diego and Riverside counties. They are now known to be in 24 water bodies in Southern California.

Zebra mussels were discovered in San Justo Reservoir in San Benito County in January 2008.

Both species can attach to and damage virtually any submerged surface.

They can ruin a boat engine by blocking the cooling system and causing it to overheat; can jam steering equipment, putting occupants and others at risk; and require frequent scrapping and repainting of boat hulls.

The mussels also can colonize underwater substrates such as boat ramps, docks, lines and other underwater surfaces, necessitating constant cleaning, and can do damage requiring costly maintenance, repair or replacement of equipment.

A multi-agency effort that includes DFG, the Department of Boating and Waterways, Department of Water Resources and Department of Parks and Recreation has been leading an outreach campaign to alert the public to the quagga and zebra mussel threats.

A toll-free hotline at 1-866-440-9530 is available for those seeking information on quagga or zebra mussels.