Western Pacific Stock Assessment Review


Tier 1: Main Hawaiian Bottomfish Stock Assessment 2009

Document(s) Reviewed

Brodziak, J., R. Moffitt, and G. DiNardo
2009. Hawaiian bottomfish assessment update for 2008. NOAA Pacific Islands Fisheries Science Center, Administrative Report H-09-02, 93 p.
[download] (1.3 MB PDF)

Supplemental Document(s)


Review Date(s)

15-19 June 2009

Review Venue

Hawaii Tokai International College, Honolulu

Review Panel

Dr. Milani Chaloupka*
Ecological Modeling Services, Australia

Dr. Cathy Dichmont
CSIRO Marine and Atmospheric Research, Australia

Dr. Robert Skillman (chair)*
Fishery Biologist (retired), Honolulu, Hawaii

Dr. Dave Somerton
NOAA Alaska Fisheries Science Center, Seattle, Washington

Dr. Kevin Stokes**
Stokes.net.nz Ltd
Wellington 6035, New Zealand

*Member, Scientific and Statistical Committee, WPRFMC
**Solicited by Center for Independent Experts


Deepslope bottomfish in Hawaii, consisting of a grouper and several species of snappers, support important fisheries and provide significant benefits to commercial and non-commercial fishers and consumers. Commercial fishing of the multi-species bottomfish complex has occurred in separate management zones in the populated main Hawaiian Islands (MHI) and the remote, largely unpopulated Northwestern Hawaiian Islands (NWHI). Fishing in the NWHI ended on January 1, 2010, under provisions of the Northwestern Hawaiian Islands Marine National Monument.

A stock assessment and risk analysis of the bottomfish complex in the main Hawaiian Islands was conducted in 2008 by staff of the Pacific Islands Fisheries Science Center, resulting in a technical report by PIFSC scientists Jon Brodziak, Robert Moffitt, and Gerard DiNardo (see "document reviewed" above). The assessment involved revision of the underlying model of bottomfish population dynamics used in previous assessments and significantly updated and amended fishery statistics and other model inputs. The assessment and risk analysis using fishery data through 2004 showed that bottomfish fishing mortality was excessive in the MHI. This led to decisions by the Western Pacific Fishery Management Council, National Marine Fisheries Service, and State of Hawaii to implement seasonal closures and other restrictions of the commercial fishery in the MHI.

Given the potential impact of the management decisions on fishers and consumers in Hawaii, there was a critical need to conduct a peer review of the scientific information and stock assessment used to inform the management decisions. The Brodziak et al. (2009) report, along with supporting and clarifying information provided in separate scientific documents and presentations, was critically reviewed by a panel of independent experts, the first undertaking of the new Western Pacific Stock Assessment Review (WPSAR) process, jointly governed by the Pacific Islands Fisheries Science Center (PIFSC), the NOAA Fisheries Pacific Islands Regional Office, and the Western Pacific Fishery Management Council. The Tier 1 review panelists worked together to produce a consensus report. One of the panelists was a scientist provided by the Center of Independent Experts (CIE) through a solicitation by PIFSC. In addition to contributing to the joint panel report, the CIE reviewer was charged with simultaneously conducting an independent peer review of the same subject matter and preparing a separate report of these independent findings to the CIE. The CIE reviewer's report was also to summarize the full panel's findings and conclusions.

Terms of Reference

The Tier 1 panelists were asked to work under the following terms of reference:

  1. Review the adequacy and appropriateness of data sources used for the stock assessment, including current research data collection, to improve bottomfish stock assessment.
  2. Review the assessment methods used: determine if they are reliable, properly applied, and adequate and appropriate for the species, fisheries, and available data.
  3. Evaluate the implementation of the assessment model: configuration, assumptions, and input data and parameters (fishery life history); more specifically determine if data are properly used, if choice of input parameters seem reasonable, if models are appropriately specified and configured, assumptions are reasonably satisfied, and primary sources of uncertainty accounted for.
  4. Comment on the scientific soundness of the estimated population benchmarks and management parameters (e.g. MSY, FMSY, BMSY, MSST, and MFMT) and their potential efficacy in addressing the management goals stated in the relevant FMP or other documents provided to the review panel.
  5. Evaluate the adequacy, appropriateness, and application of the methods used to project future population status.
  6. Suggest research priorities to improve our understanding of essential population and fishery dynamics necessary to formulate best management practices. Comment on alternative data sources and modeling, including any potential fishery independent data sources that could be used to supplement fisheries data. Include guidance on single species models, and whether this is possible given the current nature of this multispecies fishery, and difficulties in partitioning fishing effort between species.
  7. Draft a report of the Tier 1 panel's conclusions and findings, addressing each Term of Reference, for presentation to the Council's Scientific and Statistical Committee's 101st meeting, and the Western Pacific Council's 145th meeting in July 2009.

WPSAR Reviewer Report(s)

The following report of the Tier 1 review panel was prepared by the panel chair, Dr. Robert Skillman.

In addition, the CIE peer reviewer, Dr. Kevin Stokes, completed a separate, independent report for the CIE (and also contributed to the panel's report), commenting that the findings of the two reports are convergent. The panel reconvened on 7 October 2009 to allow additional public comment on the bottomfish stock assessment. Subsequently, the CIE reviewer prepared an Addendum to his final report. The complete report of the CIE reviewer is provided here.