Based on its glittery name, the golden mussel appears to be the state bivalve of California.

Unfortunately, the creature’s only connection to the Golden State is the fact that it’s the most recently identified invasive species in California — and it’s a bad one, with the ability to clog major water supply lines. water.

On October 17, tiny freshwater molluscs, which once besieged the waterways of southern South America, were discovered on Rough and Ready Island near Stockton. Since then, state officials said, the incident has occurred in at least one other location, in O’Neill Forebay in Merced County.

Its appearance in the Sacramento-San Joaquin Delta is the first confirmed detection of the mussel in North America, according to a press release from the California Department of Fish and Wildlife.

It is also very likely just the beginning of a long battle to slow its spread. The biggest concerns at the moment are potential impacts on the environment and on the Delta pumping stations that supply water to 30 million people and millions of acres of farmland.

Unless it is contained and eliminated immediately, said Peter Moyle, a biologist at UC Davis, it may not be possible to get rid of it.

“If we get lucky and have a real eradication effort in the area where it’s currently found, it might not cost too much and would be worth it,” he said.

But if those efforts fail, mussels competing for food could become a major problem for native species.

The Department of Fish and Wildlife is already considering these worst-case scenarios.

“The species poses an immediate and significant threat to the ecological health of the Delta and all state waters, water systems, infrastructure, and water quality,” officials wrote staff.

The Ministry of Water Resources already conducts inspections of vessels in hopes of preventing the spread of mussels. In the San Luis State Recreation Area, officials inspected watercraft exiting O’Neill Forebay, San Luis Reservoir and Los Banos Creek Reservoir, said Tanya Veldhuizen, state recreation section manager. special projects of the department. The inspections aim to “ensure that all water is drained from live wells and holds to prevent the spread of invasive species to other bodies of water.”

The department, she said, is also taking enhanced measures to protect the State Water Project — the system of pumps, pipes and canals that exports Delta water to the South. This increased vigilance to mitigate “biofouling of mussels,” she said, requires more frequent inspections, as well as cleaning and rinsing. Mussels, she said, are likely to accumulate in sieves, colanders and trash cans.

Originally from China and Southeast Asia, golden mussel – taxonomically Limnoperna fortunei – attaches to underwater surfaces, forming thick “reefs” made up of millions of animals. They feed by filtering nutrients and plankton from the water and, through this passive action, can have devastating effects. Essentially, they filter nutrition from the native food web. In Argentina and southern Brazil, where golden mussels appeared in the 1990s, they have driven out other species and choked out river beaches and native vegetation. Scientists have watched them spread north as fast as 150 miles per year, and they fear the invaders will make their way into the world’s largest river system and hottest biodiversity hotspot on the planet, the Amazon basin.

They have also wreaked havoc on underwater infrastructure, from hydroelectric plants to water supply systems. Mussels, for example, are reported to have clogged the intake pipes of an urban water supply system in Lake Guaíba in Brazil.

No one can know for sure how the mussels arrived in California, but sources suspect they arrived the same way they would have traveled to South America: in the bowels of commercial ships, where ballast water used to stabilize ships at sea is often disposed of. the port of arrival.

Not everyone is particularly surprised either. Moyle, for his part, said he’s been expecting golden mussels to arrive in the state for years. The California Delta, he noted, has been described as one of the most invaded estuaries in the world. It was colonized by at least 185 foreign species, from Himalayan blackberries and figs to black sea bass, striped bass and water hyacinth. Invasive Species Make Up a Staggering Share, According to One Estimate 95% or more of the total biomass of the estuary. The coypu, a large aquatic rodent native to South America, has spread into the estuary in recent years amid fears that it could, among other things, damage sea walls with its burrows.

Some Asian bivalves already live in the Bay and the Delta. THE Eurasian clamto begin with, spreads by waterway in the 1980s. Biologists say the species likely played a role in the disappearance of native fish by absorbing the tiny food particles on which they depend. The failure to recover the Delta smelt, for example, has been linked to the spread of these clams.

Now, scientists fear that golden mussels could add to those pressures.

But not necessarily. Moyle said the delta is already so heavily impacted, and its food resources already claimed, by other species – notably filter-feeding clams – that there may be no room for the golden mussel to thrive. move there.

“Invasive clams take up a lot of niche space,” he said.

On the other hand, Moyle said, “it could be a super-invader” — an invasive species so adaptable and persistent that it replaces other invaders that came before it. He said the average temperature and salinity range of the delta’s water is ideal for golden mussels.

But in such ecologically trashed place like the Delta, not everyone worries about another bump in the road. Brett Baker, water attorney at the Central Delta Water Agency and sixth-generation Sutter Island resident — and former Moyle biology student — isn’t fazed by the golden mussel’s appearance.

“All my life I’ve heard alarms about quagga mussels, zebra mussels, mitten crabs and coypu,” he said. “I just don’t think there’s enough slack in the system, or enough niche space, especially for a species that hasn’t evolved to live here…I’m pretty sure we won’t be talking no more golden mussels in 20 years. , but I could be wrong.