Big Bear Lake, CA, January 3, 2013 – In a major development with an aquatic invasive species the Big Bear Municipal Water District (MWD) has been on guard against, quagga and zebra mussels have been found for the first time in a Southern California water body that does not receive water from the Colorado River.

The mussels were discovered on the shoreline of Lake Piru in Ventura County, attached to a patrol boat and on devices used to detect the invaders. California Department of Fish and Wildlife staff have tentatively identified the half-inch mussels as quagga, but genetic testing is needed to confirm that. Lake Piru Recreation Area staff are in the process of determining the scope of the infestation; to contain it, they’re requiring all boaters to clean, drain and dry their watercraft when they leave the lake.

Native to Eurasia, the freshwater mussels multiply quickly, encrusting watercraft and infrastructure, competing for food with other species, and clarifying water to the extent that sunlight is able to penetrate deeper than normal and promote the growth of algae. The mussels can be spread from one body of water to another attached to nearly anything that has been in an infested waterbody, or via standing water.

The MWD has long stated its precautions to inhibit the spread of the zebra and quagga mussels:

  • If your vessel is traveling from another lake or the Colorado River, it should remain dry and out of water for at least seven days prior to entering Big Bear Lake.

  • Thoroughly wash the hull of each watercraft once it is out of the water, removing all plants and animal material.

  • Drain any water through the vessel’s hull plug, and ensure the area is dry.

  • Ensure the vessel’s lower outboard unit is drained and dry.

  • Clean and dry any live-well aboard the vessel.

  • Empty and dry any buckets.

  • Dispose of all bait in the trash.

See KBHR’s related stories below.