[an error occurred while processing this directive] CWQMC Bioaccumulation Oversight Group

Bioaccumulation Oversight Group

The Bioaccumulation Oversight Group (BOG) is a subcommittee of the SWAMP Roundtable that provides oversight of SWAMP's statewide bioaccumulation monitoring program.  The BOG is also a workgroup of the California Water Quality Monitoring Council, and in this role manages the Safe to Eat Portal and is a forum for coordination of bioaccumulation monitoring in California. The mission of the BOG is to assess the impacts of contaminants in fish and shellfish on beneficial uses in California water bodies through statewide monitoring under SWAMP and perform syntheses of information from other studies, and to develop an internet portal that presents this information to decision-makers and the public in a form that they can easily use. See the Workgroup Charter for more information.

Quick Links


  • SWAMP Establishes Long-Term Monitoring Plan for Mercury in Lakes – In 2015 SWAMP established and began implementing a plan for sampling and analysis of sport fish in a long-term program to track status and trends in concentrations of mercury and other contaminants in the many California lakes where bass species are present.  Bass species (including largemouth, smallmouth, and others) are at the top of the food chain and consequently tend to accumulate high concentrations of mercury.  Past SWAMP sampling showed that many lakes have mercury concentrations in bass that are above thresholds for concern.  The plan calls for sampling 190 bass lakes throughout the state on a 10 year cycle.  The sampling is being done in five rounds with 38 lakes in each round and the rounds occurring every other year.  This plan will address the critical need of managers and the public for updated, high-quality information on the status of contaminant bioaccumulation in these important water bodies.  The plan is designed in a way that will also allow tracking of statewide and regional trends in mercury contamination of lake food webs as they responds to factors such as increasing global atmospheric emissions and climate change.  Understanding these background trends is critically important in evaluating the effectiveness of statewide and regional mercury control plans (TMDLs).
  • BOG Wildlife Study - Statewide survey finds fish-eating birds at risk in many lakes (December 2015)
Monitoring Council Logo SWAMP Logo

Monitoring Studies and Reports

Monitoring is performed on the state's lakes and reservoirs, coastal waters, and rivers and streams. Click on the links below for further information on the studies and to download the reports.

lakes and resevoirs LAKES AND RESERVOIRS

BOG studies in Lakes and Reservoirs are the Statewide Lake and Reservoir Survey of contaminants in sport fish in 2007-2008; the Wildlife Study examining mercury risks to birds in 2012-2013 (see below for full description); the Low Concentration Study to characterize “clean” lakes in 2014; and the Long-term Monitoring Study to monitor mercury trends, initiated in 2015.
coastal waters COASTAL WATERS

This Coastal Fish Survey was the largest of its kind ever conducted in California. Sport fish were collected in 2009 and 2010 from 68 locations on the California coast. A total of 3,483 sport fish representing 46 species were collected and analyzed for contaminants.
rivers and streams RIVERS AND STREAMS

In 2011, 568 fish representing 16 species were collected from 63 river and stream locations in the first-ever systematic statewide survey of California rivers and streams.
rivers and streams WILDLIFE STUDY

The Wildlife Study (2012-2013) developed and demonstrated methods for monitoring mercury in two closely-related avian wildlife species that are widely distributed across the state’s lakes and reservoirs. Monitoring mercury in blood proved to be a particularly effective technique for obtaining estimates of wildlife risk across all of the lakes. The study also provided guidance on the prey fish monitoring that is needed to support estimation of wildlife risk, when wildlife cannot be directly sampled.

Additional Reports:




  • The Water Boards' Surface Water Ambient Monitoring Program (SWAMP) formed a subcommittee, the Bioaccumulation Oversight Group (BOG), to develop plans for and guide implementation of SWAMP bioaccumulation monitoring.

  • The California Water Quality Monitoring Council designated the BOG as its work group for assessing "Is it safe to eat fish and shellfish from our waters?" and directed this work group to develop an Internet portal devoted to this theme.
  • The BOG is currently collecting and analyzing fish tissue for mercury, legacy pesticides, and other bioaccumulated pollutants, such as PCBs and assessing these data to provide insight into the safety of eating sport fish.

  • The BOG has assessed data from historic Toxic Substance Monitoring (TSM) and State Mussel Watch (SMW) programs, as part of a thorough review of past bioaccumulation monitoring in California.

  • In 2012, the BOG began a study of methylmercury bioaccumulation in birds on California lakes and reservoirs. Other BOG activities include development of an overarching strategy for bioaccumulation monitoring in California and development of a plan for screening for biotoxins.

  • The BOG has convened a Bioaccumulation Peer Review Panel to provide evaluation and peer review of the bioaccumulation program. The members of the Panel are internationally-recognized authorities on bioaccumulation monitoring.

  • Workgroup Charter



  • Jay Davis - San Francisco Estuary Institute
SFEI waterboards
California Fish and Wild Life Office of Environmental Health Hazard Assessment
US EPA US Fish & Wildlife Service
USGS Moss Landing Marine Laboratories

Participating State Agencies

  • California Department of Fish and Wildlife
  • Central Coast Regional Water Quality Control Board
  • Central Valley Regional Water Quality Control Board
  • Lahontan Regional Water Quality Control Board
  • Los Angeles Regional Water Quality Control Board
  • North Coast Regional Water Quality Control Board
  • Office of Environmental Health Hazard Assessment
  • San Diego Regional Water Quality Control Board
  • San Francisco Bay Regional Water Quality Control Board
  • State Water Regional Water Quality Control Board

Participating Federal Agencies

  • U.S. Geological Survey

Other Participating Organizations

  • San Francisco Estuary Institute
  • Moss Landing Marine Laboratories
  • Southern California Coastal Water Research Project

SWAMP Bioaccumulation Peer Review Panel

  • Jim Wiener - Retired (formerly Distinguished Professor, University of Wisconsin, La Crosse)
  • Chris Schmitt - USGS, Columbia, Missouri
  • Harry Ohlendorf - CH2M Hill, Sacramento, California

More Information

  • For additional information on the Bioaccumulation Oversight Group, please email Jennifer Salisbury or phone (916) 319-0232.

Receive updates by email regarding activities of the Bioaccumulation Oversight Group. Subscribe online to the Bioaccumulation Oversight Group (BOG) email list.



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