We facilitated a scientific peer review of the 2020 California halibut stock assessment on behalf of the California Department of Fish & Wildlife


California halibut (Paralichthys californicus) is a large, predatory flat fish that lives in nearshore, soft bottom ocean habitat. Populations have been fished actively since before the beginning of California landings records in 1916 and continue to support important commercial and recreational fisheries off California. To ensure that fishing levels are sustainable and do not result in an overfished stock, managers develop stock assessments that establish the status of the fishery resource. Stock assessments are a highly informative management tool used by the California Department of Fish and Wildlife (CDFW) to monitor the abundance of fish populations, determine the level at which a resource may be sustainably exploited, and sometimes to predict the consequences of policy decisions. External, independent peer review of the scientific underpinnings of the stock assessment is one way to provide the CDFW and stakeholders assurances that it is based upon the best readily available scientific information.

California Ocean Science Trust is serving the State by convening an independent scientific peer review panel that will review the underlying scientific and technical merits of the draft stock assessment, ensuring the science underpinning this process represents the best scientific information available and is appropriately used.

Scope of Review

CDFW is seeking an independent assessment of whether the technical components, models, analysis techniques and the applications of the analyses that underpin the draft stock assessment are applied in a manner that is scientifically sound, reasonable, and appropriate. Ocean Science Trust worked closely with CDFW to develop a terms of reference that captures the scope and process of the review, focused on key components of the stock assessment where independent scientific review would be most valuable.

Review Process

  1. Select a review mode. A combined in-person and remote review process (adapted to a remote-only setup in response to COVID-19) was selected in consultation with CDFW to promote core review principles.
  2. Assemble review team. Ocean Science Trust convened a 3-4 member review panel composed of stock assessors and other experts.
  3. Conduct review. Review panelists engaged directly with CDFW, to effectively understand the stock assessment, as well as convened in independent remote meetings, maintaining transparent, candid and independent assessment.
  4. Develop and share final report. Reviewers will contribute to the development of a final peer review summary report, which will be made publicly available online.
  5. Convene public webinar to share stock assessment and peer review findings. Following the completion of the peer review, OST will convene a public webinar to facilitate equitable access to the information. This webinar will provide an overview of the 2020 stock assessment and peer review process, including goals and key findings. CDFW staff and members of the peer review panel will present information and be available to answer questions.
    • A summary of the informational webinar, providing a high-level overview of webinar goals, presentations, and participant contributions will be made available to the public following the webinar. Additional webinar details can be found above.


  • Dr. E.J. Dick, NOAA Southwest Fisheries Science Center (panel Chair)
  • Dr. Kiva Oken, University of California Davis
  • Dr. David Sampson, Oregon State University
  • Dr. Chantel Wetzel, NOAA Northwest Fisheries Science Center

Public Sharing Webinar

On October 28th, 2020, Ocean Science Trust, in partnership with California Department of Fish and Wildlife (CDFW), hosted a public informational webinar to share the key findings of the 2020 California halibut stock assessment scientific and technical peer review.

The webinar introduced participants to CDFW’s analysis to understand the status of the California halibut stock, and provided an overview of the peer review process and key findings of the scientific and technical peer review panel. The goal of the webinar was to initiate engagement with those interested in learning about the stock assessment and review process and become involved in California halibut fishery management as CDFW continues to design a process that is science-based and stakeholder-driven.

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