California’s Fish and Game Commission has taken an emergency action that it hopes will help halt the spread of the golden mussel, an invasive mollusk discovered two months ago in the Port of Stockton.
The measure makes it illegal to possess, transport or import live golden mussels.
The move by the commission at its December meeting adds the tiny bivalves to the list of “restricted species” in California, joining crocodiles, elephants, aardvarks, manatees, slugs and white perch, to name a few. All are banned from the state without a special permit in an effort to protect agriculture and the environment from being overrun by nonnative varmints.
Golden mussels aren’t the first invasive mollusk in the state — zebra and quagga mussels have also been a problem — but they are being treated as potentially more dangerous.
The species is considered a threat to infrastructure and boaters alike. Though small — the mussels are little more than half an inch and up to 2 inches in length — they can encrust and clog water, sewage and other pipes. They are considered difficult and expensive to remove.
Initially found Oct. 17 in Stockton, the mussels subsequently have been discovered in waterways farther south. That has led to fears they will continue to infest more of the state’s rivers and channels. They likely were brought from Asia as stowaways on ships and could have been released through ballast water.
The Fish and Game Commission said it hopes that listing the mussels as restricted will prevent them from showing up in even more locations around the state. The alarm is fueled in part by how readily the bivalves have taken hold in other countries, including Hong Kong, Japan, Taiwan, Brazil, Uruguay, Paraguay and Argentina
“Golden mussels are a bigger threat to California waters than quagga and zebra mussels because they can thrive in a wider range of water quality conditions,” Jay Rowan, chief of the California Department of Fish and Wildlife’s fisheries branch, said in a statement. “Putting golden mussels on the restricted species list is an important first step toward containment and prevention of spread of this nonnative species.”
To stop the spread of the mussels in the Delta, boat owners have been advised to clean, drain and dry their vessels whenever they are lifted out of the water.
Anyone who suspects they have encountered golden mussels is asked to take clear, close-up photos, using a suitable object to show the size and scale of the mollusks, and immediately report the findings online to the Department of Fish and Wildlife. Reports can also be emailed to Invasives@wildlife.ca.gov or by calling (866) 440-9530.