‘New Threat’: Invasive Species Overcomes Life in Delta, No Help Along the Way

from Rachel BeckerCalMatters

This story was originally published by CalMatters. Sign up for their newsletters.

Streams of slime ran between Jeff Wingfield’s fingers as he methodically crushed a handful of golden clams, popping the little invaders’ shells like blisters.

“You can just plow your way right through them,” Wingfield said from the dock where he stood in Stockton Harbor, looking down at the thimble-sized debris in the palm of his hand.

Last October, a few miles down the Stockton Deep Sea Ship Channel, state water managers first discovered that golden clams have invaded North America.

Seeing how quickly they’ve multiplied over the past year “was like a punch in the gut,” said Wingfield, the port’s deputy director.

Mussels are known for their voracious appetites, which fuel their rapid growth. Now state and local water managers are fighting to keep the golden clams from reaching uncontaminated lakes and reservoirs. They are racing to keep them from damaging the pumping equipment that sends Delta water to farms and cities in Central and Southern California.

But here, in the network of waterways where the Sacramento and San Joaquin rivers meet, a new reality is setting in. Dense colonies of clams now cover boats and piers and threaten water supplies for cities and farms.

In the urgent need to stop the spread, state agencies prioritized protecting the rest of the state from the Sacramento-San Joaquin Delta over protecting the delta itself. Residents and local leaders feel neglected. And they fear the stigma of a golden mussel infestation will drive visitors and boaters away from one of the country’s largest estuaries.

“It’s almost like bringing bed bugs or something from traveling abroad,” Wingfield said. “If you’ve been in the Delta now, it’s like you’ve been exposed.”

The economic consequences are enormous. Invasive species of clams and mussels cost approx 1.6 billion dollars each year, mostly in North America—costs are mostly reported as damage to business and infrastructure rather than management or prevention.

“We’re just getting started,” said Ted Grosholtz, professor emeritus at UC Davis’ Institute of Coastal and Marine Sciences. “As the population grows, the problems will grow.”

Delta whip in one year

The delta is home to nearly three quarters of a million people, half a million acres of farmland, threatened and endangered species of fish—and now the golden clam.

Native to China and Southeast Asia, the clam is believed to have slipped into a merchant ship, past long-delayed shipping rules aimed at protecting against invaders.

Now the abundant mollusk is invading critical infrastructure.

The Contra Costa Water District is reporting golden clams in multiple parts of its system. And in Stockton, the heart of the invasion, the municipal utility department found golden clams on an oil boom near their water intakes.

Travis Small, deputy director of the department’s water resources division, said he is concerned about the raw water pipeline that transports Delta water to their treatment plant and plans to hire a diver to inspect the facility’s fishing nets and pump out the well. He calls the rapid spread “disturbing.”

Mussels have even begun to appear on the irrigation siphons that pipe water from the Delta to farmland. Although the San Joaquin County Farm Bureau and Delta Irrigation Districts have not reported clogged pipes, Keith Lyons, a diver who inspects underwater equipment, said he is already seeing clams on them.

A siphon said he was so thickly encrusted that the clams are piled two inches deep, both inside and out.

“There’s a lot. A hell of a lot,” Lyons said. “I’m worried about farmers. There’s no quick answer. There’s no Roundup.”

Dennis Peluca, a pest control advisor, also noticed clams on the siphons for Rindge Tract, an island west of Stockton, to irrigate crops.

There were so many clams hanging from the outside of the tube that it looked like a beard, he said. Inside, “if it gets to the point where the arteries get clogged with cholesterol, then that’s what you’re going to deal with. That’s going to clog them up.”

The consequences could be devastating for agriculture, they said Christopher Neudeckpresident of the construction firm of Kjeldsen, Sinnock & Neudeck, and district engineer for many of the Delta Islands. The region produces dozens of different cropsand bringing in more than $4.6 billion in agricultural production.

“If (the siphons) get clogged, we’re going to lose billions of dollars worth of agricultural production,” Neudeck said. “We know it’s become extremely problematic. But nothing has been done. We’re just in a holding pattern, waiting to let the other shoe drop.”

Wingfield has also been battling invasive clams in Stockton Harbor for the past year. He worries they could block inlets to vital water systems, including an aerator that maintains legally required oxygen levels in the shipping channel.

Standing on the dock, Wingfield’s colleague Stephen Bender pulled out of the water sampling plates deployed to help staff track the invasion.

The bottom was cleared of clams in late summer, but by October it was completely covered again. The clams grew on the clams.

Bender tore a handful off the plates with a sound like velcro ripping.

No help arrives

Despite all the emerging and anticipated consequences of the invasion, the state has no specific funding or plans to address the damage in the Delta.

California lawmakers apportioned $20 million in Proposition 4 funds this year to combat golden and other invasive clams across the country. But according to the Department of Fish and Wildlife, none of it has been set aside to protect the delta or help it adapt.

Other money pots, like those of the department Boating Access Grant Programcould in theory help fund eligible golden clam control projects in the Delta, but they are not specifically designed for that purpose.

Member of the Assembly Rhodesia RansomDemocrat from Stockton, called the $20 million an initial investment and said the Legislature’s Delta Caucus is looking at what else its members can do. She called for federal help.

“These things are obviously coming from another region, another country — and that means all of our waterways are at risk,” Ransom said, calling the clams a “serious emerging threat” to farms, water supplies and recreation.

But Congressman Josh Harder federal legislation aimed at combating the invasion of the Delta is at a standstill.

“It’s difficult to pass bills from California in this Congress,” said Harder, the Democrat who represents San Joaquin and parts of Stanislaus and Contra Costa counties, which introduced the bill. “This should not be a partisan issue.”

While Gov. Gavin Newsom is pushing for a A $20 billion tunnel to send more Delta water to farms and cities in Central and Southern California, the clam adds to the growing sentiment of the inhabitants that the Delta is under siege—seen more as a water pipeline than as a place with its own living ecosystems, crops, and farms to defend.

“We really feel left out,” said Brett Baker, a water advocate and sixth-generation farmer in the region. “If you were expecting help from the state, you’d be foolish — because at the same time as this is happening, they’re going ahead with the (tunneling) procedures to gut the Delta.”

A silver bullet?

In the absence of state or federal aid, some still hold out hope that something might one day eradicate the clams from the Delta.

A few miles from the harbor, at the Delta Marine Yacht Center boatyard, Bob Parsons stared at the dripping undercarriage of the work barge he had pulled from the water.

Back in March, he had coated each pontoon with a different type of paint — an experiment to see which one was better at preventing the buildup of water hangers, such as algae. Small shells protrude from both pontoons seven months later.

“It’s such a small amount compared to what I’m seeing,” Parsons said.

Parsons hopes for a silver bullet, but scientists agree that one is not forthcoming. The Invasion is already too established and the Delta too complex.

Still, like many others, he’s pinning at least some of his hopes on a compound developed by Invasive Species Corporation, a Davis-based startup founded by scientist and entrepreneur Pamela Marrone.

The Zequanox product is already being used to control other invasive mussels, such as the species that have taken up residence in the Great Lakes and parts of Southern California. Marrone’s team also optimized it for the golden clam.

Marrone cautions that controlling clams in pipes, inside boats and other water infrastructure is possible. But removing the clams from the delta is “probably not feasible or cost-effective.”

Without a fix within the Delta, boaters are grabbing whatever they can get their hands on – like special paints or using ultrasonic sound waves to make their vessels inhospitable to invaders.

Meanwhile, Parson’s team rips hundreds of pounds from their hulls. And a sense of worthlessness creeps along the shores and docks.

A committed community

On a warm evening in October, 85-year-old Gene Belli strolled along Dock J at the Village West Marina and Resort in Stockton. A great white heron followed, making its way down the trail in the low light, looking for dinner.

J dock has become Belli’s community in the year since his wife died. “These are all my neighbors,” Belli said, walking past the other boats belonging to a bartender, a contractor, a tech supervisor. “A lot of times, like a Friday night or a Saturday night, you’ll see a band right here solving the world’s problems.”

His friend of 20 years, 75-year-old boat mechanic Fred Weisma, keeps his yacht down just a few times. Golden seashells clog the thruster and decorate the underside of his boats.

Vijsma waged a private war against the small invaders. He keeps the clams he scrapes off his boat in a coffee can and kills them with salt—an act of part science, part revenge. The smell of dead clams, even in the open air, was overwhelming. And his concern about how the clams would harm this region and his friends was palpable.

“Just for the short period of time that we’ve had these clams, it’s completely devastating,” Weisma said. “What do we do? How do we fix this? We don’t want to leave our boats.”

This article was originally published on CalMatters and is republished under Creative Commons Attribution-NonCommercial-No Derivatives license.