San Justo Mussel Eradication Project

Project ID: 1610
Principal Investigator: Scott OMeara
Research Topic: Invasive Species
Funded Fiscal Years: 2016
Keywords: None

Research Question

What concentrations of potash are needed to effectively eradicate mussels in San Justo Reservoir?

Need and Benefit

Potash is known to be lethal to mussels, yet its efficacy is variable depending on the water quality and temperature. This research gives dose curve data for the eradication of mussels in San Justo Reservoir.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

San Justo Mussel Eradication Project (final, PDF, 255KB)
By Denise Hosler
Publication completed on September 30, 2016

The invasive exotic zebra mussel (Dreissena polymorpha) has colonized San Justo Reservoir. A group of personnel from Reclamation Mid Pacific Region, California Department of Fish and Wildlife, San Benito County, and the San Benito County Water District, is proposing an attempt to eradicate the mussels by treating the reservoir with potassium provided in the form of muriate of potash (MOP). The successful mussel eradication at Millbrook Quarry (Virginia) established that water treated with MOP at 100 ppm potassium can be lethal to mussels. A suitable treatment for achieving 100% kill at San Justo reservoir may be constrained by time available for treating the reservoir (water storage and delivery obligations) and the seasonal changes in water quality parameters, therefore an evaluation of the site-specific dose and temperature effects on mussel mortality over time was necessary. This study was conducted as a proofof- concept for a MOP treatment to kill zebra mussels at San Justo reservoir, and to provide data to help refine the final eradication plan. The results of this study were successful and a future peer reviewed publication of the data results is anticipated.

San Justo Mussel Eradication (final, PDF, 1.1MB)
By Scott O'Meara
Research Product completed on September 30, 2018

This research product summarizes the research results and potential application to Reclamation's mission.

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Last Updated: 6/22/20