Ecological Impacts and Possible Environmental Controls of Zebra/Quagga Mussels on Reclamation Reservoirs

Project ID: 6003
Principal Investigator: Chris Holdren
Research Topic: Invasive Species
Priority Area Assignments: 2013 (Zebra and Quagga Mussels)
Funded Fiscal Years: 2013
Keywords: quagga mussels, zebra mussels, mussel control

Research Question

Zebra/quagga mussels have been linked to changes in the physical, chemical, and biological interactions in lakes and reservoirs. One of the most notable changes in water quality is an increase in clarity, while potential biological changes include changes in zooplankton community composition and a potential increase in cyanobacteria and algal toxin production. Can results from previous research projects be used to demonstrate those effects on Reclamation reservoirs? A closely related question is can water quality be used as a predictor of potential mussel infestations in Reclamation reservoirs?

Two previous projects, 2113, Zebra & Quagga Mussels: Pre- and Post-Impacts of Zebra/Quagga Mussels on the Physical, Chemical, and Biological Attributes on Reclamation Reservoirs, and Project ID 2358, Ecological Impacts of Dreissenids on Cyanobacteria Producing Toxins in Western Reservoirs, attempted to answer some aspects of these questions, but there was not sufficient data to answer those questions. Increased accessibility to the water quality database produced during Reclamation's ARRA Mussel Detection Program for Reclamation Reservoirs (ARRA Project), and a combination of continuing spread of mussel populations and improved detection methods leading to more positive detections, may now allow those questions to be answered.

Need and Benefit

Reclamation's ability to detect of zebra and quagga mussels at early stages of introduction has increased significantly as a result of the ARRA Project and the research conducted by the Mussel Lab. Translating the results of early detection into risk of occurrence or infestation will help Reclamation managers effectively plan and budget for mussel control for those reservoirs where risk appears to be significant.

Cyanobacteria blooms appear to be increasing in frequency and severity, and algal toxins may represent the next major area of concern for reservoir managers. Evaluation of algal toxin data could prevent closures of Reclamation reservoirs to recreation and may also prevent health risks. There is evidence in the literature that the presence of dreissenid mussels may lead to increased algal blooms, so the data analyzed during this project may also be able to answer that question.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Not Reviewed

The following documents were not reviewed. Statements made in these documents are those of the authors. The findings have not been verified.

Factors Affecting the Spread of Dreissenid Mussels in Western Reservoirs (final, PDF, 815KB)
By Chris Holdren
Report completed on June 03, 2014

• Reclamation had been using substrate sampling
to look for mussels since the 1990s
• Adult quagga mussels were discovered in Boulder
Basin, Lake Mead, in January 2007
• Reclamation's Technical Service Center (TSC)
started early detection monitoring in Lake Mead
in March 2007, and at other locations, primarily
along the Colorado River, in May 2007
• Reclamation found veligers along the entire
length of the Colorado River by May 2008, with
positive detections at most sites on the initia

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Last Updated: 6/22/20