Invasive golden mussels are the most urgent threat to Lake Tahoe’s clarity and water quality. Imagine stepping into the water at Sand Harbor. Instead of iconic blue, it’s cloudy green. Algae floats near the surface. Tahoe’s granite rocks are covered in dense colonies of invasive mussels that weren’t there last summer.
That’s the reality for some lakes where golden mussels have taken hold, and Tahoe could be next. They’re spreading fast across California, threatening to shut down water systems, damage boats, and fuel harmful algae blooms.
They are not currently in Lake Tahoe, and with your help, we can keep it that way.
Photo credit: Science.org
What are Golden Mussels?
Golden mussels are an invasive species of freshwater mollusk, originally from Asia, that were first discovered in North America in October 2024. Since then, they’ve spread across more than 300 miles of the state, from Bakersfield to Lake Oroville.
They’re small, fast-spreading, and nearly impossible to remove once established. They encrust any hard surface: dock pilings, water intake pipes, boat hulls, and even beach rocks. Their colonies are dense, sharp, and destructive. They can encrust, damage, and even cripple infrastructure like water pipes. They are filter feeders that concentrate nutrients which fuel algae growth and make harmful algal blooms — and unsafe water conditions — more likely.
Unlike some aquatic threats, golden mussels don’t just spread on boats. They cling to all your favorite water toys, like paddleboards, e-foils, floaties, life jackets, fishing gear, and even water shoes. They can survive over a week without water, making every gear bag and rooftop carrier a possible vector for golden mussels to their new habitat.
Too Close for Comfort: A Recent Close Call at Lake Tahoe
On May 30, 2025, golden mussels were detected and removed from a boat headed for Lake Tahoe. It was stopped at a watercraft inspection station in Alpine Meadows just in time. If it had launched into the Lake, Tahoe’s future might look very different today.
That close call is a warning: Golden mussels are not a distant threat. They have been found in our backyard, last reported in the Sacramento-San Joaquin Delta of California. And unless every one of us takes prevention seriously, they could be in Tahoe next.
Photo credit: Water Education Foundation
What’s at Stake if Golden Mussels Reach the Lake?
Golden mussels are filter feeders that concentrate nutrients in the water. That creates the perfect environment for algae to bloom. If mussels enter Tahoe, they can:
- Turn blue water green by triggering algae growth.
- Make swimming unsafe during harmful algal blooms.
- Clog pipes and damage water infrastructure.
- Cost millions with never-ending maintenance and cleanup.
- Encrust every surface in sharp, slimy shells, from boats to beaches.
Once they’re here, it’s too late. Prevention is the only option.
Everyone has a Role, and it Starts Before You Hit the Water
Whether you’re launching a motorized boat, kayaking and paddleboarding, or just using your favorite floaties (we see you, giant inflatable flamingo), you’re part of the front line in the fight against golden mussels.
What to do every single time:
- Clean your gear: Remove any plant material, mud, or debris from boats, boards, water shoes, and fishing tackle.
- Drain all water: Open and drain compartments, ballast tanks, and coolers.
- Dry completely: Golden mussels can survive more than a week out of water. Make sure everything is fully dry before launching.
Mobile clean, drain, dray station
Try the CD3: A Clean, Drain, Dry, Dispose Machine
The League is making prevention even easier with the CD3 stations available around the Basin. See how easy it is to use and do your part. These mobile tools help prevent the spread of invasive species:
- Pressurized air to blow out compartments
- A vacuum and brushes to remove moisture, mud, and plant debris
- Easy, free, mobile access for all users
Find a CD3 station at:
Whether you’re heading to the Lake or leaving it, use the CD3 station to Clean, Drain, and Dry and keep aquatic invaders from spreading. Visit tahoekeepers.org to watch a step-by-step Clean, Drain, Dry video and take the Tahoe Keepers pledge.
Clean, Inspect, Decontaminate: What Every Boater Needs to Know
If it touches the water, it needs to be Cleaned, Drained, and Dried. That applies to powerboats, kayaks, paddleboards, e-foils, fishing gear and even your water shoes.
Here’s how to make sure your gear is golden mussel-proof:
Motorized watercraft
- Must be inspected and decontaminated before launching in Lake Tahoe
- Schedule an appointment at tahoeboatinspections.com
- Vessels with a Tahoe inspection seal from a previous Lake launch may re-launch without reinspection
- Decontamination fees may apply
Non-motorized watercraft
- Should be Cleaned, Drained, and Dried between every use
- Free decontamination is available at boat inspection stations for hand-launched vessels
Prevention is the Key
Lake Tahoe has successfully prevented the introduction of quagga and zebra mussels. That’s thanks to strong policies, science-based inspections, and public participation. It’s a track record to be proud of and one we need to build on.
In response to the golden mussel threat, the Tahoe Regional Planning Agency (TRPA) and Tahoe Resource Conservation District (TRCD) have stepped up motorized watercraft inspection requirements. These changes are designed to protect the Lake proactively — before it’s too late.
History shows that when we act early, work together, and follow the science, we can prevent invasive species from taking hold.
Your next steps:
- Join our Eyes on the Lake citizen science program and learn how to identify and report aquatic invasive species: keeptahoeblue.org/eol.
- Take the Tahoe Keepers pledge and share the Clean, Drain, Dry video with your community: tahoekeepers.org
- Schedule your watercraft inspection: tahoeboatinspections.com
- Talk about it: Share this blog and the risk of golden mussels with your friends, family, and fellow Tahoe-lovers.
Lake Tahoe’s clarity isn’t guaranteed. But with your help, we can Keep Tahoe Blue.
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