NO MUSSEL BEACHHEAD IN THE EASTERN SIERRA… YET

Published in the Dec. 27, 2025 issue.

Gold built California. Now, a different kind of gold is infesting it.

The invasive golden mussel, first detected in California last October, is spreading fast and putting nearly every waterway at risk. The mussel, which can do severe damage to fisheries and water infrastructure, has already spread through the Sacramento–San Joaquin Delta and down much of the west side of the state, effectively to the Mexican border.

Luckily, the mussel is not in the Eastern Sierra yet, and its introduction is “not inevitable,” according to CDFW Fisheries Supervisor Nick Buckmaster, who presented at both the Eastern Sierra Council of Governments and at the Mono County Board of Supervisors earlier this month. 

That is, if local agencies can pull together a management plan and pool enough funds to execute it before the fishing season opens in April.

“The analogy I’ve come up with is, we got pitched out of a plane, and we’re figuring out a parachute on the way down,” Buckmaster explained.

Golden mussels are close relatives of quagga and zebra mussels, which have plagued waterways across the United States for decades. But golden mussels are worse.

They can tolerate a wider range of conditions (saltier, colder waters) and survive longer out of water than their better-known cousins. They also have an invisible larval stage, meaning a boat can look clean and still transport live mussels in residual water trapped in motors.

Once the mussels are introduced to a body of water, they are nearly impossible to remove. They clog pipes and destroy water infrastructure, forcing early and costly replacements, and as filter feeders they strip out the base of the food chain, undermining fisheries and collapsing fish populations.

“What it looks like in the infrastructure is unreal. It’s tremendous. These mussels grow rapidly and alter the water chemistry,” described Lori Gillem, representative for the Los Angeles Department of Water and Power (LADWP). “What they’re gonna do to our fisheries and our water system up here is going to be unbelievable.” 

When they die, the mussels leave behind a rank layer of shells and decaying tissue along shorelines, degrading beaches and further harming recreation. 

Infrastructure costs can also skyrocket. In heavily infested areas elsewhere in the country, water and power bills have increased by 200-300% as agencies struggle to keep pipes clear, Buckmaster said.

Unlike the west side of California, the Eastern Sierra is not directly connected to the state’s water delivery network, which is already contaminated with golden mussels. That isolation gives the region a chance of escaping the infestation, but only if action is taken quickly.

Here, the main threat is boating. Trailered watercraft moving between infested waters on the west side and local lakes are the most likely pathway for introduction. And because golden mussels can survive in most Eastern Sierra lakes, the list of vulnerable waters is far longer than it was with earlier mussel threats.

“In the past, the risk [of invasive mussel species] was mostly limited to a handful of lakes like Crowley,” Buckmaster said. “Now, almost every recreational lake here could support them.”

CDFW and its partner organizations have developed a short-term regional plan centered on boat inspections and education. 

At the core of the proposal is a county ordinance requiring trailered boats entering Mono County and Inyo Counties to pass an inspection and display a color-coded sticker on their trailer. Similar programs are already in place in Lake County and in Tahoe. The stickers would change monthly, making enforcement easier and turning inspections into a mandatory education point for boaters.

“The safest thing to do would be to shut down all boating,” Buckmaster said. “That’s not realistic, and it’s not something my agency is pushing. Inspections are something we can actually do, and they work.”

To support the program, planners identified the need for three additional inspection stations to supplement the existing LADWP station at Crowley Lake. The estimated cost for a one-year startup phase is about $60,000, to be split among participating agencies. That figure does not include long-term administration or enforcement.

Nonprofit partners, including CalTrout, have also applied for roughly $500,000 in grant funding to cover equipment and startup costs.

State support, however, will be modest.

CDFW has received one-time funding through Proposition 4 earmarked for golden mussel prevention, which Buckmaster said will be used to hire short-term staff, train local agencies and purchase inspection and decontamination equipment. 

It will not fund a permanent, state-run inspection program.

“The state is in a huge deficit,” Buckmaster said. “We’re not going to be able to do this on our own.”

Instead, the state’s role will focus on training, monitoring and technical assistance, leaving long-term implementation to counties, water agencies and local partners.

He asked ESCOG last Thursday to consider taking ownership of the project, but board members expressed doubts about the board’s capacity to manage long-term funding or staffing for full implementation. Instead, they sent it back to the individual counties. 

On Tuesday, Buckmaster told the Mono County Board of Supervisors that a draft ordinance mandating inspection stickers would need to be ready by the end of January to allow time for outreach and enforcement before the boating season kicks off in April. 

He plans to meet with Inyo County, the Town of Mammoth Lakes, the City of Bishop, and local Public Utility Districts in the coming months to encourage a region-wide effort.

“You can rebuild after a wildfire,” he said. “You can’t get rid of these animals.”