Left, black dog laying on asphalt beside a sign that reads  "RESTRAIN YOUR PET K-9 ON DUTY CHECKING FOR AQUATIC INVASIVE SPECIES" Right, golden colored dog walking on asphalt in front of a green boat.
Mussel dogs at work

Mussel Dogs to Help Stop Aquatic Hitchhikers at Lopez Lake

Author: Public Works
Date: 6/28/2023 10:01 AM

LOPEZ LAKE – On July 3-July 4, 2023, mussel sniffing canines will be helping public officials at Lopez Lake inspect vessels for invasive aquatic species – otherwise known as quagga or zebra mussels. “Mussel dogs”, as they’re called, sniff around boats, alerting handlers to the presence of mussels and dramatically decreasing the time it takes to inspect boats.

To expedite the inspection process, boaters are encouraged to follow these simple guidelines when entering or leaving any water way:

  • Inspect all exposed surfaces – small mussels feel like sandpaper to the touch
  • Wash the hull of each watercraft thoroughly
  • Remove all plant and animal material
  • Drain all water and dry all areas (including the lower outboard unit)
  • Clean and dry all live-wells, and dispose of any unused bait in the trash
  • Empty and dry any buckets and compartments

All vessels entering San Luis Obispo County lakes will be inspected for zebra and quagga mussel. Vessels will not be allowed to launch if they have visited a mussel infested lake within the last 30 days or fail the vessel inspection.

Zebra and quagga mussels “hitch” rides on boats and travel to other lakes, causing damage to the lake’s natural environment, and boating and water equipment.  Once a lake is infested, it can be expensive to manage the mussel infestation.  Preventing their spread is the best course of action. 

The County of San Luis Obispo appreciates boaters’ assistance in protecting local water resources.  The public can assist in educating others about the importance of responsible boating by remembering to CLEAN, DRAIN, and DRY all boats and equipment before visiting local lakes and being prepared to have boats inspected prior to launching. 

For further information on invasive mussels, the County of San Luis Obispo’s Mussel inspection program, and the current listing of infested lakes visit: