Lake and Reservoir Bioaccumulation Monitoring Surveys

The Bioaccumulation Monitoring Program’s lake and reservoir surveys have focused on the long-term sampling and analysis of sport fish to track status and trends in fish tissue concentrations of contaminants in the many California lakes and reservoirs where bass and other species are present.

Quality Assurance Project Plan (QAPP) 2023 2025, July 2023

Long-Term Monitoring | Low Concentration Survey | Screening survey

Long-term Monitoring Survey (2015, ongoing)

The Long-term Monitoring Survey was initiated in 2015, and will continue to monitor long-term trends in mercury concentrations in lakes dominated by bass (a fish species known to accumulate high levels of mercury). This study will provide updated information on the status of these lakes and a statewide perspective on long-term trends to support the evaluation of management action effectiveness (e.g., mercury control plans) as well as the impacts of factors such as increases in global emissions or climate change on fish mercury levels. Monitoring occurred in 2015, 2017 and 2019, and is planned for 2021, 2023 and 2025.

• Monitoring Plan, November 2022 [0.8 MB]
• Quality Assurance Project Plan (QAPP), October 2021 [1.2 MB]
  • SWAMP Bioaccumulation Monitoring Program Data Validation Standard Operating Procedures
• Monitoring Plan, October 2021 [0.8 MB]
• Quality Assurance Project Plan (QAPP), September 2017 [15.3 MB]
• Monitoring Plan, June 2015 [1.5 MB]


• 2023 Cruise Report [52 MB]
• 2021 Cruise Report [54 MB]
• 2019 Cruise Report [22 MB]
• 2017 Cruise Report [5.6 MB]
• 2016 Cruise Report [9.9 MB]
• 2015 Cruise Report [7.2 MB]


• 2019 Data Report [5 MB]
• 2017 Data Report [18 MB]
• 2016 Data Report [12 MB]
• 2015 Data Report [17 MB]

Low Concentrations of Contaminants Survey (2014)

The Low Concentration Study, conducted in 2014, was designed to identify and characterize 'clean' lakes (those with low levels of mercury and other contaminants in fish) to better inform the fishing public and to gain a better understanding of the factors and conditions contributing to the lower concentrations.

• Final Technical Report (2018) [11.7 MB]
• Monitoring Plan
• Clean Lakes Cruise Report (2014)
• Region 7 - Colorado River Basin RWQCB Cruise Report (2014)
• Quality Assurance Project Plan (QAPP)
  • Report Only
  • Appendices
    • Appendix 1
    • Appendix 2
    • Appendix 3
    • Appendix 4
    • Appendix 5
    • Appendix 6
    • Appendix 7
    • Attachments
  • Full QAPP with Appendices [50MB]

Statewide Lake and Reservoir Screening Survey (2007 - 2008)

The Statewide Lake and Reservoir Survey, conducted in 2007 and 2008, was California's largest ever survey of contaminants in sport fish from lakes and reservoirs. Popular fishing locations at a total of 272 lakes and reservoirs were sampled throughout the state.

Final Documents

• Press Release
• Fact Sheet
• Frequently Asked Questions
• Report Only
• Appendices
  • Appendix 1
  • Appendix 2
• Full Version with Appendices
• Media - 2010
• Year-Two Cruise Report [16.9 MB]

Year 1 Documents

• Press Release
• Fact Sheet
• Frequently Asked Questions
• Report Only
• Appendices
  • Appendix 1
  • Appendix 2
  • Appendix 3
  • Appendix 4
• Full Version with Appendices
• Contaminants in Fish from California Lakes and Reservoirs [Presentation]
• Media - 2009
• Year-One Cruise Report [16.9 MB]

Supporting Documents

• Monitoring Plan
• Quality Assurance Project Plan
• Access to Data
  • INSTRUCTIONS ON HOW TO ACCESS THE TISSUE DATA FOR THIS PROJECT:
    • Instructions on how to access tissue data
    • Tissue button in the RESULT CATEGORY:
    • Select > Programs > Surface Water Ambient Monitoring Program > Done
    • Select > Projects > SWAMP Sportfish Contamination in Lakes & Resrv > Done
    • Select > Turn on automatic station mapping (stations will be mapped on the map)
  • MAP STATIONS/PARAMETER COUNTS ON WEB-BASED MAP
    • Select > Map Stations
    • Click on individual stations>
    • Select > Parameter Counts (see data)
  • RETRIEVE DATA
    • First, complete the instructions above under: “INSTRUCTIONS ON HOW TO ACCESS THE TISSUE DATA FOR THIS PROJECT”
    • Select > Retrieve Data (as an Microsoft Excel File)
      • Then download (save) data
      • File identified in Cell A:1 > CEDEN: Data Retrieval
      • This file summarizes fish attributes (length, weight, etc.) and the associated chemistry results.
    • To get the individual attributes of the composited fish (no chemistry)
      • Make sure your Pop-up Blocker is turned OFF
      • Include Sample Composite (notice the increase in Record Count)
      • Select > Retrieve Data
        • Then download (save) two data files (will include “Data Retrieval” file)
      • File identified in Cell A:1 > CEDEN: Sample Composite Data
        • This file is the individual attributes of the fish composites (no chemistry data)