Overview of Contaminant-Related Issues Identified by Monitoring in San Francisco Bay

Prepared by
Bruce Thompson, San Francisco Estuary Institute
Rainer Hoenicke, San Francisco Estuary Institute
Jay A. Davis, San Francisco Estuary Institute
Andrew Gunther, Applied Marine Sciences


Second Revision
August 12, 1999

RMP Contribution #36

This is a journal article for Environmental Monitoring and Assessment 64 (2000) 409-419. Kluwer Academic Publishers. Printed in the Netherlands.

Abstract

The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing suggesting continuing inputs. Episodes of aquatic toxicity often occured following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South-, and North Bay sites are moderately contaminated.

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