NOAA SWFSC Peer Reviews

Review of the 2012 Pacific Bluefin Tuna Stock Assessment

The report of the Pacific bluefin tuna stock assessment conducted by International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean can be found here: ISC Stock Assessment of Pacific Bluefin Tuna in 2012.

The Pacific Bluefin Tuna Working Group (PBFWG) of the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) conducts stock assessments of Pacific bluefin tuna to inform the ISC in its deliberations on stock status and its development of science advice for the multinational fisheries that exploit tuna and billfish stocks of the North Pacific. PBFWG stock assessments are based on the best fishery statistics and biological data available and are conducted cooperatively by scientists from ISC members China, Japan, Korea, Mexico, Taiwan, and the USA and collaborating scientists from the Inter-American Tropical Tuna Commission and the Secretariat of the Pacific Community (SPC). NOAA Fisheries SWFSC scientists contributed to this assessment.

In 2012, the PBFWG completed an up-to-date assessment, building on previous assessments of the stock. The objectives of the new assessment were to (1) understand the dynamics of Pacific bluefin tuna by estimating population parameters such as recruitment, biomass and fishing mortality; (2) determine stock status by summarizing results relative to potential target and limit reference points (including MSY-based reference points); and (3) enable formulation of scientific advice for fisheries managers on Pacific bluefin tuna conservation. The primary assessment work was conducted during a a series of PBFWG workshops convened in 2011 and 2012 to prepare data sets, develop biological parameters and abundance time series, investigate modeling approaches, and conduct the stock assessment. The report summarizes the efforts directed towards completing the 2012 stock assessment and reports results on the stock status and future outlook of Pacific bluefin tuna. In March 2013, SWFSC solicited independent peer reviews of the stock assessment report through the Center for Independent Experts (CIE), assisted by the NMFS Office of Science and Technology (F/ST). The CIE engaged 3 experts to independently conduct a thorough review of the stock assessment report. In addition to the stock assessment report, each reviewer was provided with ancillary documents and data, providing helpful background information.

Each expert was asked to:

1.    Review the assessment methods to provide recommendations on how to improve its application, and/or recommend other methods that would also be appropriate for the species, fisheries, and available data.

2.    Evaluate the assessment model configuration, assumptions, and input parameters (fishery, life history, and spawner recruit relationships) to provide recommendations on how to improve: the use of data, specification of fixed input parameters, and specification of model configuration.

3.    Provide recommendations on improving the treatment of assumptions (e.g. sensitivity analyses) and description of uncertainty in estimates of stock dynamics and management quantities (e.g. reference points).

4.    Provide recommendations on improving the adequacy, appropriateness, and application of the methods used to project future population status.

5.    Suggest research priorities to improve the stock assessment including data, life history and modeling.

Each reviewer prepared a peer-review report of findings and recommendations, addressing in particular the points listed above and delivered the report to the CIE. After the CIE and F/ST verified that the peer-review reports satisfied the terms of reference, F/ST provided the reports to the SWFSC with approval for their distribution.

The independent peer review reports are posted on this web page. 

Peer Review report: Sylvain Bonhommeau

Peer Review report: Tom Carruthers

Peer Review report: Joseph E. Powers

Last modified: 12/24/2014