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Environmental Services

Dean Messer, Chief

3500 Industrial Blvd.
West Sacramento, CA 95691
(916) 376-9699

Mailing Address:
P.O. Box 942836
Sacramento, CA 94236-0001



Invasive Species

“Examination of Calcium and pH as Predictors of Dreissenid Mussel Survival in the California State Water Project”

This report was prepared under contract by RNT Consulting Inc. for the California Department of Water Resources (DWR).  The report discusses the suitability of the State Water Project (SWP) to support long-term populations of quagga and zebra mussels (dreissenids) if unintentionally introduced. 

Ten years of calcium and pH data were analyzed from 23 SWP water quality stations. Calcium and pH are essential in shell formation and survival of dreissenid mussels. Locations in the SWP were classified into one of three groups:  unable to support, potentially able to support, and able to support long-term populations of dreissenid mussels. Understanding where dreissenid mussels may survive in the SWP will be used to guide DWR in future management of this invasive species.

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