California Department of Fish and Wildlife

Evaluating Stressors in the San Francisco Estuary using Biomarkers

Sponsors: California Department of Fish and Wildlife, State and Federal Contractors Water Agency, and Interagency Ecological Program: Contaminants Work Team

Delta smelt tissue being prepared for analysis
Photo Credit: Dr. Swee Teh laboratory

Workshop Details

Agenda (PDF)

Dates: October 24-25, 2013

Tentative Times: October 24, 9:00 AM to 4:00 PM; October 25, 1:00 PM - 4:00 PM

Location: UC Davis Alumni Center

This workshop is free and open to the public. Funding for the workshop is provided by the Ecosystem Restoration Program and the State and Federal Contractors Water Agency


In 2007, the Interagency Ecological Program (IEP) convened a Task Force to evaluate the appropriate use of biomarkers to assess contaminant effects on the four declining fish species (collectively known as the POD species) in the San Francisco Estuary. The report that resulted from the Task Force (Anderson et al 2007 PDF) emphasized that in order to interpret stressor effects, geography, season, and temporal variability of the fish populations, understanding the organismal properties, life stages, and sensitivities must be taken into consideration. Furthermore, it is essential that interpretation incorporates physicochemical and anthropogenic influences - including fate and transport of contaminants, bioavailability, routes and timing of exposure (water, sediment, and food), chemical properties, and concentrations.

Much research has been conducted over the six years since this workshop was held. Current interest extends beyond the POD species to include additional listed species (e.g., green and white sturgeon and various salmonids), and other species of interest (e.g., inland silversides and Sacramento splittail). Biomarkers continue to be an important integrative tool.

Staff from several agencies are working through the IEP Contaminants Work Team (CWT) to assess what has been learned since 2007, what progress has been made in the state of knowledge, and, if the technology is ripe, how to use and interpret biomarkers in the San Francisco Estuary. The Work Team has prepared a background document that presents background information, provides a conceptual model, summarizes recent and ongoing studies, and poses questions for discussion by a Science Advisory Panel.


The independent Science Advisory Panel consists of the following scientists:

  • Tracy Collier, Panel Chair, Delta Independent Science Board, Delta Stewardship Program
  • Nancy Denslow, University of Florida
  • Evan Gallagher, University of Washington
  • Dave Lattier, US EPA
  • Mitch Kostich, US EPA

Charge to Panel

Using the material presented, namely the background document, the reference documents, and the presentations from the public workshop, the Science Advisory Panel will respond to the questions posed in the background document as well as:

  1. Assess the potential application of biomarkers for evaluating stressors and/or adverse effects on San Francisco Estuary fishes;
  2. Identify biomarkers that should be focused on in future San Francisco Estuary research; and,
  3. Identify data gaps and develop a research framework to guide the role and application of biomarkers within the Bay-Delta ecosystem.

Questions for Panel

The Planning Committee has prepared a background document (PDF) that frames each of the questions below by providing relevant information related to each question. The questions have been excerpted from the background document for presentation here.

Ecosystem Monitoring

  • How can biomarkers help us understand the relative health of organisms and the natural variability in these measured conditions?
  • What is the relative importance of biomarkers on individual organisms and population health?
  • How can current biomarker systems be used strategically to determine whether anthropogenic, physicochemical, and/or biological influences are causing significant stress in SFE species?
  • What is the relative importance of these stressors to individual and population-level impacts, and thus ecosystem functioning?
  • How can baselines, references or controls be established for field-based assessments?
  • How can spatio-temporal variability be incorporated into biomarker data analyses?
  • What are the relevant pros and cons of which we need to be aware or cautious?

Additional Questions

  • What specific information on health condition should be obtained to support biomarker assessments and monitoring? Consider contaminant transport and fate, bioavailability, and bioaccumulation, in conjunction with physicochemical and biological influences.
  • What are the current benefits and limitations of the use of single versus multi-biomarker approaches?
  • What is the suitability of current biomarkers and/or novel approaches such as genomics, proteomics and metabolomics, to monitoring population health?
  • How can biomarker systems be used to assess effects of these stressors, and their interactions within 1) field populations? 2) laboratory studies? and 3) in-situ/ex-situ exposures?
  • How best can field and laboratory based studies be integrated, from a biomarker perspective?
  • How do non-lethal vs. lethal sampling limit the use of biomarker assessments?
  • Should multiple species or a single species be selected as a model for biomarker investigations? Which species and why?
  • How can AOPs or associations with higher levels of biological organization be integrated into the Delta monitoring approaches?
  • How best can we integrate life histories, and specific life stages into planned studies?
  • What additional information should be collected to aid interpretation of biomarker data?
  • What analytical approaches would likely be most useful for interpreting biomarker data and understanding its environmental relevance?
  • How do we extrapolate biomarker findings to fundamental fitness parameters such as survival, growth, and reproduction?


Oct. 24 - Workshop from 9AM - 4 PM at UC Davis Alumni Center (Presentations - see agenda)

Oct. 25 - Workshop from 1PM - 3 PM at UC Davis Alumni Center (Panel Reports out, final discussion)

December - Panel submits response to final questions

Contact Person

For more information, contact Carol Atkins at or (916) 445-0074.

Additionally, if you have comments or additional information to submit, please send them to Please do not send material to the Panel members. Thank you.