On January 6, 2023, the Metropolitan Water District of Southern California (Metropolitan) detected a single quagga mussel veliger using cross-polarized microscopy in a large volume plankton net sample collected at Metropolitan’s Foothill Feeder Pressure Control Structure, which is downstream of Castaic Lake. The veliger was confirmed as a quagga mussel by PCR and DNA sequencing.
Adult quagga mussels were previously detected by the California Department of Water Resources in Castaic Lake in August 2021.
For questions specific to Metropolitan’s facilities and response, please contact Paul Rochelle, Water Quality Section Manager, at (909) 392-5155.
For questions regarding CDFW’s response, please contact CDFW’s hotline at (866) 440-9530.