Boaters heading for area lakes this Fourth of July should expect to give an accounting of where they've been and what they may have picked up along the way.
Authorities are on the lookout for quagga and zebra mussels, invasive species known to hitchhike from one body of water to another by attaching themselves to boat trailers, hulls, engines and steering components.
Agencies from Lake Tahoe to Folsom Lake are taking measures to keep the mussels – which no one knows how to get rid of – out of their waters. Efforts range from educating the public through billboards and brochures, to surveying boat owners and inspecting watercraft before they're launched.
"We have 13 inspectors out at various launches inspecting and doing risk assessments," Nicole Cartwright of the Tahoe Resource Conservation District said last week. She is part of the Lake Tahoe Aquatic Invasive Species Working Group.
She said decontamination stations will operate around the lake this weekend to handle watercraft found to harbor mussels.
The mussels hail from Eastern Europe, around the Black and Caspian seas. They arrived in the United States about 20 years ago, likely transported on the hulls of ships.
First reported in the Great Lakes, the mussels recently were found in 19 Southern California lakes and waterways, as well as in the San Justo Reservoir in San Benito County.
The mussels can damage boats, but of greater concern are their effects on the environment and water delivery systems. Once introduced to a lake, the fingernail-size mussels attach themselves to aquatic plants, water intake pipes and fish screens. They disrupt the ecological balance by consuming nutrients needed to support native fish and aquatic plants, and clog water lines and irrigation systems.
A female mussel can produce up to a million eggs in a season, and the microscopic larvae may feel like sand on a boat's hull.
Pete Lucero, spokesman for the federal Bureau of Reclamation, which operates Folsom Lake, said the bureau has been working on eradication plans should an infestation occur, but to date no methods have been identified.
No natural predators or chemical or biological treatments have been found to get rid of the mussels in the United States, experts say.
Folsom Lake is a major water source for communities and agencies throughout the Sacramento region, including the city of Sacramento, Folsom, Carmichael, Fair Oaks, Roseville, Folsom Prison and the El Dorado Irrigation District.
The bureau has been working with the California Department of Parks and Recreation, which oversees recreational activities at the lake, to prevent mussels from being introduced.
The program currently is limited to posting notices around the lake and distributing mussel information cards to people as they drive into the recreational area, Lucero said. Monitoring devices also are being placed in the lake to detect mussels.
The El Dorado Irrigation District announced plans to install monitors at Jenkinson, Silver, Caples and Echo lakes. The district is considering spending about $135,000 this year on educational efforts and a boat-screening program.
District employees propose surveying boaters before they launch to determine whether the craft have been in infested waters, and conducting random inspections.
"We need to really take this action right off the bat and get the message out that we mean business," Don Pearson, district recreation director, said in outlining the program for board members last week.
He proposed charging boaters an additional fee of up to $8 to cover the program's cost.
Cartwright, of the Tahoe Resource Conservation District, said the program there is largely funded through grants. She estimated prevention efforts would cost about $1 million this year.
Inspections, which can take from 10 minutes to an hour, will continue through Labor Day, she said.
Some agencies, including the East Bay Municipal Utility District, are taking a tougher stance. Web sites for the district's Lake Camanche and Pardee Reservoir, southwest of Jackson, advise boaters that because of the mussel threat, all boats from outside California, as well those from Southern California and San Benito and Santa Clara counties, will be turned away this season.
For more information, or to view videos about the mussels and how to conduct a boat inspection, see the El Dorado Irrigation District's Web site at www.eid.org.
Call The Bee's Cathy Locke, (916) 608-7451.
