Lake Sonoma and Lake Mendocino plan for stronger measures to ward off invasive mussels
Lake Sonoma and Lake Mendocino were ringed in recent years by the telltale signs of drought, their diminished water levels leaving exposed earth that in wetter years is well-submerged.
Winter and spring runoff helped to replenish the two reservoirs, which together supply much of the North Bay’s drinking water and provide popular destinations to cool off in the summertime.
But a big threat to the two lakes remains in the form of tiny mollusks — quagga and zebra mussels — that are invading fresh water bodies across California and the West, hitching rides from one lake or reservoir to another on boats and trailers.
The bivalve mollusks, imports from Eastern Europe, swiftly colonize large areas, clogging intake pipes, covering docks and damaging other infrastructure while upending aquatic ecosystems.
Their spread, from the Southwest and north from Southern California, has reservoir operators throughout the state on high alert. For several years, Lake Sonoma and Lake Mendocino have been on the front lines of that endless fight, officials say.
“Aside from the drought, the threat of invasive mussels taking hold in either of the two lakes is one of the most significant issues facing our region today,” said state Sen. Mike McGuire, D-Healdsburg, who called the reservoirs “prime targets for infestation,” given their popularity among boaters.
The federal agency that oversees Lakes Sonoma and Mendocino is set to step up its fight against the mussels with mandatory boat inspections slated to begin over the next year.
The program will be supported by $600,000 in state grant funds collected through a statewide, annual $8 boat registration fee. Already, officials are beefing up staff training at the larger Lake Sonoma under a campaign to screen incoming boats for quagga and zebra mussels.
The Sonoma County Water Agency also provides specially trained dogs at the reservoirs on weekends with the ability to sniff out the mature specimens, about the size of a fingernail, as well as the juveniles, called “veligers.” The seasonal program is in its third year.
But officials are eager to implement a more stringent system with mandatory inspections for boats coming to either of the reservoirs after exposure to other bodies of water that may be contaminated. Across California, 33 bodies of water have been infested over the past decade, with the last new discovery made in 2014.
While complex and expensive, officials say an inspection plan is imperative and overdue.
“For three years, we’ve been working to secure these dollars which will launch a region-wide program to stop these invasive buggers from invading our waterways and we couldn’t be more excited to secure this important prevention grant,” McGuire said.
The program likely would include some kind of banding mechanism, such as one used at Lake Tahoe, that would allow boaters only using one of the two reservoirs to avoid the scrutiny applied to vessels that have been launched elsewhere.
The Sonoma County Water Agency, which handles reservoir releases in cooperation with the Army Corps, applied for a two-year grant in 2014, with plans of having an inspection system by early 2015. The application was turned down because the Army Corps is the official reservoir owner and operator, Water Agency spokesman Brad Sherwood said.