CIE Peer Review

Subject Stock Assessment of Yellowfin Tuna in the Western and Central Pacific Ocean
Document(s) Reviewed
Hampton J, Kleiber P, Langley A, Takeuchi Y, Ichinokawa M
2005. Stock assessment of yellowfin tuna in the western and central Pacific Ocean. Western and Central Pacific Fisheries Commission, Scientific Committee, 1st Regular Session, 8-19 August 2005, Noumea, New Caledonia. WCPFC-SC1/SA WP-1.
Download (1.9 MB PDF)
Date October 2006
Background

Stock assessments for yellowfin tuna in the western and central Pacific Ocean (WCPO) are conducted by the Oceanic Fisheries Programme 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 2005 assessment indicated that overfishing of yellowfin tuna was likely to be occurring in the WCPO. The 2005 assessment was more pessimistic than previous yellowfin assessments for the WCPO. The most influential change in the 2005 assessment was due to differences in the relative weightings applied to different model regions, essentially down-weighting the proportion of the total longline exploitable biomass of yellowfin tuna occurring in the non-equatorial regions. The assessment was the basis for scientific advice on the status of the yellowfin tuna stock that is provided regularly at both national and regional levels, and directly influences U.S. policy on resource utilization.

In 2006, 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. Before the review was completed, the report of the 2006 yellowfin tuna stock assessment became available. Although the review primarily considered the 2005 stock assessment, the 2006 assessment report was also consulted and taken into account where appropriate. Both assessments used essentially the same base model, although the sensitivity analyses changed. The 2005 assessment document was supplied by the CIE and other supporting articles were provided on request or acquired from the website of the OFP. The review covered a number of articles describing the background and development of various aspects of the model, and focused on those aspects which seem to have had the greatest influence on the assessment.

The CIE provided 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 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, recommend values for alternative management benchmarks (or appropriate proxies) and provide 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.

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.

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. Paul A. Medley
Fisheries Consultant
Alne, UK
Comments (0.1 MB PDF)

Dr. Michel Bertignac
IFREMER
Centre de Brest, Laboratoire de Biologie Halieutique
Plouzané, France
Comments (0.1 MB PDF)