{"id":271314,"date":"2025-11-04T17:30:09","date_gmt":"2025-11-04T17:30:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/271314\/"},"modified":"2025-11-04T17:30:09","modified_gmt":"2025-11-04T17:30:09","slug":"emerging-threat-an-invasive-species-is-upending-life-in-the-delta-with-no-help-on-the-way","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/271314\/","title":{"rendered":"‘Emerging threat’: An invasive species is upending life in the Delta, with no help on the way"},"content":{"rendered":"

By Rachel Becker<\/a>, CalMatters<\/p>\n

\t\t\t\t\""An\"
\n\t\t\t\tAn underwater view of golden mussels growing on a dock at a Delta boatyard in Stockton on Oct. 23, 2025. Photo by Fred Greaves for CalMatters<\/p>\n

This story was originally published by CalMatters<\/a>. Sign up<\/a> for their newsletters.<\/p>\n

Spurts of goo oozed between Jeff Wingfield\u2019s fingers as he methodically crushed a handful of golden mussels, popping the shells of the tiny invaders like bubblewrap.\u00a0<\/p>\n

\u201cYou can just push your way right through them,\u201d said Wingfield from the dock where he stood at the Port of Stockton, looking down at the thimble-sized debris in his palm.\u00a0<\/p>\n

Last October, a couple of miles down the Stockton Deepwater Shipping Channel, state water managers first discovered<\/a> that golden mussels had invaded North America.\u00a0<\/p>\n

Seeing how fast they\u2019ve multiplied in the last year \u201cwas like a gut punch,\u201d said Wingfield, a deputy director at the port.\u00a0<\/p>\n

The mussels are infamous for voracious appetites that fuel their rapid growth. Now, state and local water managers are battling to keep golden mussels<\/a> from reaching uninfested lakes and reservoirs. They\u2019re racing to keep them from damaging the pumping facilities that send Delta water to farms and cities in Central and Southern California.\u00a0<\/p>\n

But here, in the web of waterways where the Sacramento and San Joaquin Rivers meet, a new reality is setting in. Thick colonies of the mussels already coat boats and piers and threaten water supplies for cities and farms.\u00a0<\/p>\n

In the urgency to\u00a0 stop the spread, state agencies have prioritized protecting the rest of the state from the Sacramento-San Joaquin Delta, over protecting the Delta itself. Residents and local leaders feel overlooked. And they fear that the stigma of a golden mussel infestation will drive visitors and boaters away from one of the country\u2019s largest estuaries.\u00a0<\/p>\n

\u201cThat\u2019s almost like bringing bedbugs or something back from a trip overseas,\u201d Wingfield said. \u201cIf you\u2019ve been in the Delta now, it\u2019s like you\u2019ve been exposed.\u201d<\/p>\n

\""A\"Sampling plates hauled from the water at the Port of Stockton were completely encrusted with mussels on Oct. 23, 2025. The plates are used to track the golden mussel invasion. Photo by Fred Greaves for CalMatters\u00a0<\/p>\n

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\""The\"
\nFirst: A worker scrapes golden mussels from a pontoon on a work barge at a Delta boatyard. Last: A buoy with golden mussels on it at the Port of Stockton on Oct. 23, 2025. Photos by Fred Greaves for CalMatters<\/p>\n

The economic consequences are looming large. Invasive mussel and clam species cost an\u00a0 estimated $1.6 billion<\/a> every year, largely in North America \u2014 costs overwhelmingly counted in damage to business and infrastructure, rather than management or prevention.\u00a0<\/p>\n

\u201cWe\u2019re just getting started,\u201d said Ted Grosholz, a professor emeritus with the UC Davis Coastal and Marine Sciences Institute. \u201cAs the populations grow, the problems will grow.\u201d<\/p>\n

A Delta scourge, one year in<\/p>\n

The Delta is home to nearly three quarters of a million people,<\/a> half a million acres of farmland, threatened and endangered fish species \u2014\u00a0and now, the golden mussel.\u00a0<\/p>\n

Native to China and Southeast Asia, the mussel is suspected to have slipped in on a commercial ship, past long-delayed shipping rules<\/a> aimed at keeping out invaders.<\/p>\n

Now, the abundant mollusk is invading critical infrastructure.\u00a0<\/p>\n

The Contra Costa Water District reports golden mussels in multiple parts of its system. And in Stockton, the heart of the invasion, the municipal utilities department found golden mussels on an oil containment boom near their intakes.\u00a0<\/p>\n

Travis Small, deputy director of water resources at the department, said he\u2019s concerned about the raw water pipeline that transports Delta water to their treatment plant, and plans to hire a diver to inspect the utility\u2019s fish screens and pump well. He calls the rapid spread \u201cworrisome.\u201d\u00a0<\/p>\n

The mussels have even started appearing on irrigation siphons that pipe Delta water onto farmland. Though the San Joaquin County Farm Bureau and Delta irrigation districts haven\u2019t reported clogged pipes, yet, Keith Lyons, a diver who inspects underwater equipment, said that he\u2019s already seeing\u00a0the mussels\u00a0on them.<\/p>\n

One siphon, he said, was so thickly encrusted<\/a> that the mussels piled two inches deep, both inside and out.\u00a0<\/p>\n

\u201cThere\u2019s a lot. A heck of a lot,\u201d Lyons said. \u201cI\u2019m worried for the farmers. There\u2019s no quick answer. There\u2019s no Roundup.\u201d<\/p>\n

\""An\"An aerial view of the San Joaquin River and the adjacent farmland in Stockton, Oct. 23, 2025. The invasive golden mussel threatens boats, marinas and water supplies for cities and farms. Photo by Fred Greaves for CalMatters<\/p>\n

Dennis Pelucca, a pest control advisor, also spotted mussels on the siphons for Rindge Tract, an island west of Stockton, to irrigate crops.\u00a0<\/p>\n

So many mussels were hanging off the outside of the pipe, it looked like a beard, he said. On the inside, \u201cif it gets to the point like arteries getting clogged up with cholesterol, then that’s what you’re going to be dealing with. It will plug them up.\u201d\u00a0<\/p>\n

The consequences could be devastating for farming, said Christopher Neudeck<\/a>, president of the civil engineering firm Kjeldsen, Sinnock & Neudeck and a district engineer for many of the Delta islands. The region produces dozens of different crops<\/a>, and drives more than $4.6 billion<\/a> in agricultural output.\u00a0<\/p>\n

\u201cIf (the siphons) plug up, we\u2019re going to lose billions of dollars worth of agricultural production,\u201d Neudeck said. \u201cWe know it\u2019s become extremely problematic. But nothing has really been done. We\u2019re just in a holding pattern, waiting to let the second shoe drop.\u201d<\/p>\n

Wingfield, too, has been grappling with the invasive mussels at the Port of Stockton for the past year. He\u2019s worried they could clog intakes for vital water systems, including an aerator that maintains legally required oxygen levels in the shipping channel.\u00a0<\/p>\n

Standing on the dock, Wingfield\u2019s colleague Steven Bender hauled sampling plates from the water, deployed to help staff track the invasion.\u00a0<\/p>\n

The bottom had been stripped clean of mussels at the end of the summer, but by October was again completely encrusted. Mussels grew on top of mussels.\u00a0<\/p>\n

Bender ripped a handful away from the plates, with a sound like velcro tearing.\u00a0<\/p>\n

No help arriving<\/p>\n

For all the emerging and anticipated consequences of the invasion, the state has no specific funding or plans to tackle harms in the Delta.\u00a0<\/p>\n

California lawmakers allocated $20 million in Proposition 4 funds<\/a> this year to fight off golden and other invasive mussels statewide. But according to the Department of Fish and Wildlife, none of it is set aside to protect the Delta or help it adapt.\u00a0<\/p>\n

Other pots of money, like the department\u2019s Boating Access Grant Program<\/a>, could in theory help fund eligible projects to combat the golden mussel in the Delta, but they aren\u2019t specifically designated for that purpose.\u00a0\u00a0<\/p>\n

Assemblymember Rhodesia Ransom<\/a>, a Democrat from Stockton, called the $20 million an initial investment and said the legislature’s Delta Caucus is looking at what more its members can do. She called for federal help.\u00a0<\/p>\n

\u201cThese things came clearly from another region, another country \u2014 and that means all of our waterways are at risk,\u201d Ransom said, calling the mussels a \u201cserious emerging threat\u201d to farms, water supplies, and recreation.<\/p>\n

\""A\"Port of Stockton employee Steven Bender inspects equipment used to aerate water at the Port of Stockton on Oct. 23, 2025. Golden mussels spread rapidly and can damage pipes and pumping equipment, leading to costly repairs. Photo by Fred Greaves for CalMatters<\/p>\n

But Rep. Josh Harder’s federal legislation<\/a> aimed at combating the invasion in the Delta has stalled.\u00a0<\/p>\n

\u201cIt’s tough to get bills from California passed in this Congress,\u201d said Harder, the Democrat representing San Joaquin and parts of Stanislaus and Contra Costa counties who introduced the bill. \u201cThis shouldn’t be a partisan issue.\u201d<\/p>\n

As Gov. Gavin Newsom pushes for a $20 billion tunnel<\/a> to send more Delta water<\/a> to farms and cities in Central and Southern California, the mussel adds to residents\u2019 growing sense<\/a> that the Delta is under siege \u2014 seen more as a conduit for water than as a place with its own vibrant ecosystems, cultures and farms to protect.\u00a0<\/p>\n

\u201cWe do feel abandoned,\u201d said Brett Baker, a water lawyer and sixth-generation farmer in the region. \u201cIf you were expecting help from the state, you\u2019d be foolish \u2014 because at the same time this is happening, they\u2019re proceeding through with the (tunnel) proceedings to basically eviscerate the Delta.\u201d\u00a0<\/p>\n

A silver bullet?\u00a0<\/p>\n

In the absence of state or federal help, some still hold out hope that something, someday might eradicate the mussels from the Delta.\u00a0<\/p>\n

A few miles away from the Port, at the Delta Marine Yacht Center boatyard, Bob Parsons peered at the dripping undercarriage of the work barge he\u2019d hauled from the water.\u00a0<\/p>\n

Back in March, he\u2019d covered each pontoon with a different type of paint \u2014 an experiment to see which was better at preventing the buildup of aquatic hangers-on, like algae. Tiny shells jutted from both pontoons seven months later.\u00a0<\/p>\n

\u201cThis is such a small amount in comparison to what I’ve been seeing,\u201d Parsons said.\u00a0<\/p>\n

\""An\"An underwater view of a rope attached to sampling plates covered with golden mussels at the Port of Stockton on Oct. 23, 2025. Photo by Fred Greaves for CalMatters<\/p>\n

Parsons is hoping for a silver bullet, but scientists agree that one isn\u2019t coming. The invasion is already too established, and the Delta too complex.\u00a0<\/p>\n

Still, he like many others, has pinned at least some of his hopes on a compound being developed by the Invasive Species Corporation, a Davis-based start-up founded by scientist and entrepreneur Pamela Marrone.\u00a0\u00a0<\/p>\n

The product, Zequanox, is already used to combat other invasive mussels, like the species that have taken hold in the Great Lakes and parts of Southern California. Marrone\u2019s team is optimizing it for the golden mussel, as well.\u00a0<\/p>\n

Marrone cautions that controlling mussels in pipes, the inner workings of boats and other water infrastructure is doable. But eliminating mussels from the Delta \u201cis not likely feasible or cost effective.\u201d<\/p>\n

Without a Delta-wide fix, boaters are grasping for anything they can get their hands on \u2014 like special paints, or using ultrasonic sound waves to make their vessels inhospitable to the invaders.\u00a0<\/p>\n

In the meantime, Parson\u2019s team is ripping hundreds of pounds off their hulls. And a sense of futility is creeping across waterfronts and docks.\u00a0<\/p>\n

A community at stake<\/p>\n

On a warm evening in October, 85-year-old Gene Beley walked down J dock at the Village West Marina and Resort in Stockton. A great egret followed, picking its way down the walkway in the slanting light, looking for dinner.\u00a0<\/p>\n

J dock has become Beley\u2019s community in the year since his wife passed away. \u201cThese are all my neighbors,\u201d Beley said, passing the other boats belonging to a bartender, a contractor, a tech executive. \u201cA lot of times, like Friday or Saturday nights, you’ll see a group right here, solving the world\u2019s problems.\u201d<\/p>\n

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\""A\"
\nFirst: Fred Vijsma, owner of Fred\u2019s Yacht Service, pulls golden mussels from the underside of his dinghy. Last: Fred Vijsma holds a coffee can full of golden mussel shells scraped from his dinghy at the Village West Marina and Resort in Stockton on Oct. 23, 2025. Photos by Fred Greaves for CalMatters<\/p>\n

His friend of 20 years, 75-year-old boat mechanic Fred Vijsma, keeps his yacht just a couple of slips down. Golden mussels clog the thruster and decorate the underside of his dinghies.\u00a0<\/p>\n

Vijsma has been waging a private war against the tiny invaders. He keeps the mussels he\u2019s scraped off his dinghy in a coffee can, and kills them with salt \u2014 an act part science, part vengeance. The smell of the dead mussels, even in the open air, was overpowering. And his worry about how the mussels will harm this region, and his friends, was palpable.\u00a0<\/p>\n

\u201cIn just the short period of time that we’ve had these mussels, it’s totally devastating,\u201d Vijsma said. \u201cWhat do we do? How do we fix this? We don’t want to leave our boats.\u201d<\/p>\n

This article was originally published on CalMatters<\/a> and was republished under the Creative Commons Attribution-NonCommercial-NoDerivatives<\/a> license.<\/p>\n","protected":false},"excerpt":{"rendered":"By Rachel Becker, CalMatters An underwater view of golden mussels growing on a dock at a Delta boatyard…\n","protected":false},"author":2,"featured_media":271315,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[2342,192,145171,16592,79,107695],"class_list":{"0":"post-271314","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-agriculture","9":"tag-environment","10":"tag-josh-harder","11":"tag-sacramento","12":"tag-science","13":"tag-stockton"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/271314","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=271314"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/271314\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/271315"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=271314"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=271314"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=271314"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}