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.


  • SWAMP LogoSWAMP 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 Plans 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.

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 LifeOffice of Environmental Health Hazard AssessmentUS EPA US Fish & Wildlife Service USGS Moss Landing Marine Laboratories SCCWRP

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
  • Santa Ana 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 Resources 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 Anna Holder or phone (916) 341-5096.

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