How serious is the threat of invasive mussels such as zebra or quagga mussels?

The zebra mussel and its close cousin, the quagga mussel, have become the most serious non-native biofouling pests to be introduced into North American fresh waters. An infestation adversely affects the ecosystem and anyone who uses the lakes by causing mussel colonies to form on all surfaces including:

  • Boats
  • Engines
  • Buoys
  • Pipes
  • Water intakes
  • Ladders
  • Beaches
  • Native shellfish
  • Aquatic vegetation

The most serious measurable economic impacts are suffered by water districts and other users of lake water who may have increased maintenance costs due to plugged water pipes, intake screens, and possible damage to pumps and other equipment. It even impacts citizens who don't use the lakes through increased costs for drinking water and food prices passed along to consumers by the water and agriculture industries brought on by their increased costs in maintenance and equipment repair. It impacts the local fisheries, and in some lakes, has caused a collapse in the populations of sport fish.

These mussels have the ability to tolerate a wide range of conditions and are extremely adaptable. Once they have infected a water body, they cannot be eradicated. They have no predators native to the U.S. They cannot be prevented from spreading into downstream waters.

Show All Answers

1. What types of water vessels require screening?
2. If I launch my boat in a body of water outside of Lake County, must it be re-screened upon return to Lake County?
3. What is the penalty for launching a boat without Mussel Stickers?
4. What do I do if I see someone ready to launch without a Mussel Sticker?
5. How much does it cost to get Mussel Stickers?
6. How long are Mussel Stickers valid?
7. My patio boat has been in the waters of Clear Lake for years, do I need to pull it out of the lake and have it inspected?
8. How do I know if my boat is considered a "Resident Vessel"?
9. How/where do I get Mussel Stickers for my vessel?
10. Can I obtain my Mussel Stickers through the mail?
11. Are any of the screening locations open 24 hours per day?
12. How long will the screening take?
13. What parts of the boat and trailer will be checked during screening?
14. Will I be required to remove panels and floor boards from my boat during the screening?
15. If it is determined my boat must be decontaminated, where do I go?
16. What does decontamination of my boat consist of?
17. How serious is the threat of invasive mussels such as zebra or quagga mussels?
18. Why did the Board of Supervisors enact an inspection ordinance?
19. Have any lakes in California been infested with these mussels?
20. What can I do to help?