Prevent Spread of Invasive Mussels

A regional effort to prevent the spread of invasive quagga and zebra mussels into local waterways, including Lake Sonoma and Lake Mendocino, continues to grow after the Sonoma County Water Agency (Water Agency) and County of Sonoma Board of Supervisors agreed to join the North Coast Zebra and Quagga Mussel Consortium.  The Consortium’s goals are to increase public awareness and encourage regional prevention planning to prevent the spread of the zebra and quagga mussels into North Coast waterways.  To date, Consortium partners include the counties of Sonoma, Mendocino and Humboldt, the Sonoma County Water Agency, and the Mendocino County Russian River Flood Control and Water Conservation Improvement District.  Additional partners will be added as the Consortium continues to grow.

“By joining the Consortium, we are agreeing to work with our partners to implement proactive methods and programs to help keep boating recreation open on both Lake Sonoma and Lake Mendocino by preventing a mussel infestation,” said Water Agency Director and Sonoma County Supervisor Mike McGuire.  “Once infested with mussels, a reservoir could be closed to all boating recreation which would be a devastating blow to our local economy.  Mussels also pose a serious threat to water supply infrastructure and crucial fish hatcheries, including the Russian River Coho Captive Broodstock Program at Lake Sonoma.”  

Zebra and quagga mussels are among the most devastating invasive species to invade North American fresh waters. Mussel infestations create an immense financial burden because of the need to continuously and actively manage them.  According to the Center for Invasive Species Research, University of California Riverside, it is estimated that it costs over $500 million per year to manage mussels at power plants, water systems, industrial complexes and on boats and docks in the Great Lakes. Similar yearly management costs are anticipated for California. 

According to the U.S. Fish and Wildlife Service, both Lake Sonoma and Lake Mendocino are susceptible to a mussel infestation because of the high level of year-round watercraft recreation traffic and the lack of mandatory inspection programs. A mussel infestation at either reservoir could potentially clog water pipes and affect the release of water, thus potentially affecting the supply of drinking water to more than 600,000 residents in portions of Sonoma and Marin counties; the hydropower facilities at Lake Sonoma; and clogging the water intake pipes to fish hatcheries, including the Russian River Coho Captive Broodstock Program, operated by the U.S. Army Corps of Engineers. 

The mussel’s primary method of travel between water systems is by water flow and tailored watercraft, such as boats. Water Agency and Sonoma County Board Chair Shirlee Zane said, “We are calling on all recreational boaters and members of the public that recreate on a waterway - Don’t move a mussel.  Ensure your watercraft is clean, drained and dry before launching it.” 

The mussels first arrived in the Great Lakes from Europe in the 1980’s and have spread to many water bodies in the eastern and Midwestern United States, including California. The first confirmed find of zebra mussels in California occurred in 2008 in San Benito County at San Justo Reservoir.  That reservoir is now closed to boating recreation due to the mussel infestation. Quagga mussels have now been found in waterways within San Diego, Riverside, San Bernardino, and Orange counties.

A mussel infestation in Lake Sonoma or Lake Mendocino could impair the Russian River Coho Captive Broodstock Program’s ability to serve as a regional recovery hatchery.  If infested with mussels, the broodstock program could only distribute fish into other waters infested with mussels.  This would eliminate the ability of the program to plant rearing fish throughout the Central California Coastal and Evolutionarily Significant Unit and thus seriously impact the program’s effectiveness.

Consortium partners and the U.S. Army Corps of Engineers are working together to implement vulnerability studies and mandatory boat and watercraft inspection programs at local waterways, including Lake Sonoma and Lake Mendocino.  The Army Corps operates and manages the recreational functions at both Lake Sonoma and Lake Mendocino.  To date, a voluntary, self-imposed inspection program is in place at both reservoirs.

“The County of Mendocino is proud to support the North Coast Consortium and its efforts to keep these mussels out of our local waterways,” said Mendocino County Supervisor Carre Brown.  “Lake Mendocino is an important resource not only for our water supply and fisheries, but also for our local economy which relies on boating recreation at the lake.”

The Water Agency has created informational boat inspection cards, which beginning this summer the Sonoma County Sherriff’s Office, which patrols Lake Sonoma, will be handing out in an effort to educate boaters on how to inspect their watercrafts.  Park rangers with the U.S. Army Corps of Engineers will also be handing out the informational cards to boaters at Lake Mendocino.  Regional Parks will be installing educational signs at local waterways, including Spring Lake in Santa Rosa.   

“The Sheriff’s Office supports educating our boating community about the real threats presented by the mussels.  We are collaborating with our partners to help with this educational effort and will participate in developing a mandatory inspection program for our local waterways,” said Sonoma County Sheriff Steve Freitas.

The informational inspection cards, along with a public service announcement and more information about the mussels may be found online at www.dontmoveamussel.com.

The Sonoma County Water Agency is working to secure our future by investing in our water resources, community and environment.  The Water Agency provides water supply, flood protection and sanitation services for portions of Sonoma and Marin counties. Visit us on the Web at www.sonomacountywater.org.