CIE Peer Review

Subject Stock Assessment of Bigeye Tuna in the Western and Central Pacific Ocean
Document(s) Reviewed
Hampton J, Langley A, Kleiber P
2006. Stock assessment of bigeye tuna in the western and central Pacific Ocean, including an analysis of management options. Western and Central Pacific Fisheries Commission, Scientific Committee, 2nd Regular Session, 7-18 August 2006, Manila, Philippines. WCPFC-SC2-2006/SA WP-2.
Download (2.8 MB PDF)
Date October 2007

Stock assessments for bigeye tuna in the western and central Pacific Ocean (WCPO) are conducted by the Oceanic Fisheries Programme (OFP) of the Secretariat of the Pacific Community, with collaboration of scientists participating in the Scientific Committee of the Western and Central Pacific Fisheries Commission.

Results of the 2006 assessment indicated that overfishing of bigeye tuna was likely to be occurring in the WCPO. While the stock was not yet in an overfished state (current stock biomass (BCURRENT), defined as average total biomass during 2001—2004, exceeded the biomass producing maximum sustainable yield (BMSY)). Further biomass decline was considered likely to occur at 2001-2004 levels of fishing mortality and long-term average levels of recruitment. The current level of biomass was 28% of the unexploited level (BCURRENT/BF=0 = 0.28). While the 2006 assessment applied a similar modeling approach to that used in the prior year's assessment, there were a number of important changes including differences in the relative weightings applied to the different model regions. The assessment was the basis for scientific advice on the status of the stock that is provided regularly at both national and regional levels, and directly influences U.S. policy on resource utilization.

In 2007, The Pacific Islands Fisheries Science Center (PIFSC) solicited an independent peer review of the 2006 stock assessment by the Center of Independent Experts (CIE).

The review consisted of a desk review of the document listed above, which was submitted by OFP to the Science Committee of the Western and Central Pacific Fisheries Commission. Documents for the two previous years' bigeye tuna stock assessments (see references in the primary document) were also consulted for background information on changes over time in the assessment procedures used.

The CIE provide the report to two reviewers. Each reviewer was asked to address the following items:

  1. Comment on the adequacy and appropriateness of data sources for the stock assessment.
  2. Review the assessment methods: determine if they are reliable, properly applied, and adequate and appropriate for the species, fisheries, and available data.
  3. Evaluate the assessment model configuration, assumptions, and input data and parameters (fishery, life history, and spawner-recruit relationships): determine if data are properly used, input parameters seem reasonable, models are appropriately configured, assumptions are reasonably satisfied, and primary sources of uncertainty accounted for.
  4. Comment on the proposed population benchmarks and management parameters (e.g., MSY, FMSY, BMSY); if necessary, recommended values for alternative management benchmarks (or appropriate proxies) and clear statements of stock status.
  5. Evaluate the adequacy, appropriateness, and application of the methods used to project future population status.
  6. Suggest research priorities to improve the understanding of essential population and fishery dynamics necessary to formulate best management practices.

The independent peer reviews are posted on this web page. The reviews were also provided to the OFP.

— Samuel G. Pooley, Director

Reviewer Comments

Dr. Graham Pilling
Center for Environment, Fisheries & Aquaculture Science
Lowestoft, UK
Comments (0.3 MB PDF)

Dr. Stephen J. Smith
Department of Fisheries and Oceans Canada
Dartmouth, Nova Scotia, Canada
Comments (0.1 MB PDF)