California’s Invaders: Golden Mussel

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Announcements

Overview

four mussel shells about a centimeter long
Golden Mussel shells collected in October 2024 at a water quality station at Rough and Ready Island near Stockton in San Joaquin County, California, USA. Photo: Elizabeth Wells, Ph. D. (DWR).
  • The first North American detection of golden mussel (Limnoperna fortunei) was in October 2024. Although this mussel is similar in appearance and impacts to quagga and zebra mussels, it can establish in waters with wider temperature and salinity ranges.
  • Environmental impacts include loss of native and game fish through competition for the same food sources and as a contributor to harmful, fish killing algal blooms.
  • Recreational impacts of this mussel include waterbody closures, mandatory inspections, reduced numbers of fish and shellfish for consumption, increased launch and/or entry fees.
  • Economic impacts range include costly repairs and maintenance (boats, water infrastructure, hydroelectric facilities), reduced water flow affecting food production, water delivery to homes, and flood control.
  • For more information, review our Golden Mussel Fact Sheet (PDF).
 

Mussel Detections

This map is updated as new sightings are confirmed.

For greater detail about monitoring efforts, refer to the Golden Mussel Presence and Absence in California map

If you observe this species take clear, close up photos, using some suitable object to show scale (size) and immediately report online.

Protect The Waters You Like To Visit

The most common way that invasive mussels are unintentionally moved between waterbodies is by hitchhiking on watercraft and equipment. Keep the waters you enjoy safe and always do the following:

  • Clean, Drain and Dry (PDF) your watercraft and all equipment
  • Know before you go – contact the waterbody you plan to visit to find out about launching requirements and potential closures
  • Purchase the Mussel Fee Sticker - besides being required for all motorized watercraft operated in freshwater, funds from the purchase of the stickers go towards protecting the waters of our state.

Additional Information

Recreational Waterbody Users

Waterbody Managers

Fisheries Branch
Branch Chief: Jay Rowan
1010 Riverside Parkway, West Sacramento, CA 95605
Fisheries@wildlife.ca.gov