Lake Mendocino mussel scare prompts fury

The verdict is still out on the degree of threat posed by stowaway mussels found clinging to a boat about to launch at Lake Mendocino this past weekend, the Department of Fish and Wildlife said Monday.

But the fallout has been profound, as water managers and public officials contemplate the vulnerability of local reservoirs to infestation by invasive mussels in the absence of a boat-inspection program long promised by the Army Corps of Engineers.

Officials around the region engaged in a flurry of exchanges Monday as word of the scare at Lake Mendocino spread and, with it, alarm about the Corps’ delayed launch of mussel-prevention efforts, despite available funds.

“All the tools are there for the Corps. They just need to implement,” said Brad Sherwood, a spokesman for the Sonoma County Water Agency, which has set aside $125,000 to contribute to inspection startup costs. “We know the Corps can do a top-quality job. We just need to make sure that this issue - mussels - are a priority of the Corps, because it certainly is a priority for all their local stakeholders.”

Nicholas Malasavage, chief of operations and readiness for the Army Corps’ San Francisco District, which operates lakes Sonoma and Mendocino, said he’s aware of the damage the mussels could inflict.

“They are a menace, and they get in easy and they do not go away, so it’s hard to think of something that’s more serious,” he said.

Yet delays in developing a local prevention program have put at risk $600,000 in state grant funds obtained in 2016 for mussel-prevention programs by the Corps.

The grants expired April 30, a result of obstacles including staffing and contract management shortages and constraints on their use, Malasavage said.

Intermittent negotiations with the state Division of Boating and Waterways are ongoing to extend the use of the funds, Malasavage said.

He said Saturday’s incident renews the urgency to find solutions. A spokeswoman for boating and waterways said the state is willing to extend the grant through Dec. 31 and work with the Corps to find a way to use it, if an agreement can be reached.

“Everybody wants to get this done,” Malasavage said.

In the meantime, “our region is left extremely vulnerable,” state Sen. Mike McGuire, D-Healdsburg said.

“There are tens of thousands of fresh-water vessels all across this great state, and we know that people travel far and wide to recreate on both Lake Sonoma and Lake Mendocino,” he said. “We know that some of those vessels have been in infected waters.”

First discovered in California in 2008 and now present in at least 43 state water bodies, the two related mussels are easily spread in water or mud, or adhering to watercraft, accounting for their appearance in lakes and reservoirs across the country since their introduction to the Great Lakes via Lake Erie in 1989, likely through ballast or bilge water.

Corps personnel at lakes Sonoma and Mendocino have been on alert for most of the past decade, aware that an infestation at one of the reservoirs could rapidly alter the ecosystem and cause millions of dollars in damage to physical infrastructure critical to providing drinking water to the 600,000 residents in Sonoma and northern Marin county who are supplied through the Sonoma County Water Agency.

“The long and the short of it,” McGuire said, “is there has been agreement on all sides - the Sonoma County Water Agency, the U.S. Army Corps of Engineers, and the counties of Mendocino and Sonoma - that a permanent mussel prevention program must be in place. A lot of people have spent a lot of time to secure these funds and the Army Corps of Engineers has continued to sit on the dollars.”

He said the prospect of quagga or zebra mussels reaching one of the reservoirs has never been a question of “if,” but “when.”

That day appeared to turn up Saturday, when a group of Bay Area dads and their daughters arrived for a weekend of camping and boating at Lake Mendocino.

The group was preparing to launch three watercraft Saturday morning when a specially trained mussel-sniffing dog hit on one of the boats, on loan from a Marin County man to one of the dads in the group, the dog’s handler, Ukiah resident Lisa Cheli, said.

Cheli found tiny bivalves encrusted on various parts of the vessel and alerted park rangers and Fish and Wildlife personnel, who seized the mollusks and escorted the towed boat to a decontamination station in Lake County. The county has three such stations, part of a well-developed, decade-old mussel-prevention program designed to safeguard Clear Lake, Pillsbury and other lakes that provide the lifeblood of Lake County’s economy. When Cheli spoke by phone with the boat’s owner he provided contradictory accounts of its recent whereabouts, she said.

But a later conversation between the owner and a Fish and Wildlife warden determined the boat had been used in San Francisco Bay, and the mussels might be a saltwater species called dark false mussels, despite their close resemblance to zebra mussels, Fish and Wildlife Capt. Patrick Foy said.

Organisms collected from the boat were shipped to state scientists for analysis, and were still en route Monday.

Whether or not those mollusks posed a threat, they did provide a frightening reminder of the two reservoirs’ vulnerability, protected only by sniffer-dogs deployed two to three days a week during the warm season.

Drew McIntyre, general manager of the North Marin Water District and chairman of the Technical Advisory Committee to the Sonoma County Water Agency’s contract water suppliers, said stakeholders were unanimous Monday in reminding the Corps of its imperative to “immediately implement mussel prevention efforts.”