A boat infested with invasive golden mussels was intercepted Saturday at a mandatory decontamination site before it could enter Folsom Lake, a popular California reservoir. The discovery at Mello Marine in Folsom prevented the destructive species from potentially colonizing the lake.
Workers found clusters of golden mussels clinging to the underside of the hull during the inspection required for boats launching into the lake. Sally Mello, owner of Mello Marine, noted that while her team has decontaminated approximately 6,000 boats since 2025, this was the first encounter with golden mussels.
The boat had arrived from the Sacramento-San Joaquin Delta and had reportedly followed all required inspection and decontamination protocols. Its planned itinerary included Folsom Lake, which attracts over 2 million visitors annually, before continuing north to Oregon.
Golden mussels, scientifically known as Limnoperna fortunei, are an inedible invasive species that can accumulate pollutants and toxins. They attach to hard surfaces, posing a threat to water delivery systems, agricultural infrastructure, and the environment. Officials emphasize that once established in a waterway, golden mussels are exceedingly difficult to eradicate.
Last year, a single golden mussel was found in Folsom Lake. In a separate incident, a boater was fined $5,000 at Lake Tahoe for tampering with an inspection seal designed to prevent the spread of invasive species.
The California Department of Fish and Wildlife has been notified. The contaminated boat will undergo a full decontamination and a 30-day quarantine period before it is permitted back into waterways.