San Francisco Bay Food Web Bioaccumulation model

This model was developed to assess the effects of PCBs in wildlife and fishermen in San Francisco Bay and to identify potential risk management actions. The objective of this model is to estimate the concentrations of PCBs in a set of key species that reside in the Bay as a result of PCB concentrations in sediments and water in the Bay. 

The species that are the main focus of the study are the double-crested cormorant (Phalacrocorax auritus), the Forster’s tern (Sterna Forsteri), and the harbor seal (Phoca vitulina richardsi), as well as three fish species that are frequently caught by fishermen in the Bay, i.e. shiner surfperch (Cymatogaster aggregata), jacksmelt (Atherinopsis californiensis) and white croaker (Genyonemus lineatus). The fish species are important end-points of the model because of their role in passing PCBs to fishermen. Double-crested cormorants, Forster’s terns and harbor seals are included in the model because they have been identified as sensitive receptors of PCBs.

The model can be used to determine what concentrations of PCBs in the water and sediments of the Bay need to be reached to achieve an adequate margin of safety in wildlife and humans exposed to PCBs in the Bay area. This information can be used as part of a Total Maximum Daily Loading (TMDL) characterization to formulate remedial actions to achieve desired water quality goals.

The model is in the form of a Microsoft Excel™ workbook.

General information on the model is available in the following publication:

– Gobas FAPC, Arnot JA. 2010. Food web bioaccumulation model for polychlorinated biphenyls in San Francisco Bay, California, USA. Environ Toxicol Chem 29:1385-1395.

For more information on this model please contact Jon Arnot or Frank Gobas.

San Francisco Bay Food Web Bioaccumulation model Download Registration Form