Lake Piru’s Mussel Problems

Lake Piru, a popular Ventura County fishing and boating area just west of Castaic near the Los Angeles County border, was recently found to have invasive dreissenid mussels in its water. The big concern with these non-native freshwater mussels is their attaching themselves to boats used at Piru. Here’s part of the report:

On Dec. 18, Lake Piru Recreation Area staff reported the discovery of potential quagga mussels to CDFW. The mussels were found attached to a Lake Piru patrol boat and several additional mussels were subsequently found on devices deployed in the lake for the purpose of detecting mussels and on the shoreline.

 CDFW staff tentatively identified the mussels, which range in size from one-half to three-quarter inches long, as quagga. Genetic testing is under way to confirm this identification. Lake Piru Recreation Area staff are working to determine the full extent of the infestation.

Lake Piru, which is managed by United Water Conservation District, is located downstream of Pyramid Lake. Lake Piru drains into Lower Piru Creek, a tributary of the Santa Clara River.

 Quagga and zebra mussels, non-native freshwater mussels native to Eurasia, multiply quickly and encrust watercraft and infrastructure, and compete for food with native and sport fish species.

These 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 from an infested waterbody entrapped in boat engines, bilges, live-wells and buckets. People who launch vessels at any body of water are subject to watercraft inspections and are encouraged to clean, drain and dry their motorized and non-motorized boats, including personal watercraft, and any equipment that comes into contact with the water before and after recreating at a waterway.