Gulf SSC Review of SEDAR 74- Gulf Red Snapper

Dr. Katie Siegfried (SEFSC) provided the SEFSC's response to a review, conducted in December 2023, of the SEDAR 74 Research Track Assessment model for Gulf red snapper. The review panel comprised four SSC representatives and three Council for Independent Experts reviewers (CIE). The overall conclusion of the group was that the presented stock assessment model was not suitable to proceed to an Operational Assessment and that instead a Benchmark Assessment and another full review should be conducted. Dr. Siegfried pointed out that, while the reviewers reported a number of criticisms, they did not provide any feedback on what data gaps may be contributing to those issues and broadly recommended using a simpler modeling approach based on the data available.

One of the main issues identified was the stock structure identification (ID). The Stock ID Working Group recommended a 3-regional model; however, that decision was not unanimous. While building the model, the analysts became aware of a number of data collection limitations for the eastern Gulf region (Cape San Blas to southern Florida). As a result, the stock assessment team had to integrate data streams from the eastern region and the central region (Cape San Blas to the Mississippi River) to parameterize the three-area model. This mirroring approach to the data in two of the three regions resulted in additional inherent uncertainty but allowed for successful convergence of the model. The reviewers suggested this approach may result in an over parametrized model and recommended instead combining the eastern and central regions resulting in a 2-region model as was done in the previous SEDAR 52 red snapper stock assessment.

The SSC discussed the merits of the 2 versus 3-area model based on the review. The SSC sentiment was mixed with a few members stating that a 2-area model would be appropriate and result in less uncertainty. Others argued that, absent any direct comparison between two different models, it is impossible to actually test for utility of the regional differences in stock productivity and abundance. Instead, they contended that the 3-area model had been recommended by the Stock ID Work Group, and since the model was able to converge, should be pursued for management advice.

Dr. Cass-Calay and Council staff stated that the Research Track Assessment process has not been as useful as intended in that the gains in efficiency and throughput have not been realized and has created more workload on the data provisioning process. The SSC and SEFSC staff also discussed the need for independent peer-review of particular stock assessments (e.g., CIE review) and agreed that this could be determined on a case-by-case basis for each assessment and included in the Terms of Reference (TORs) for each stock assessment. A similar approach could be used to determine if Topical Working Groups or other panels are necessary for each assessment. The SSC plans to continue this discussion at its next meeting.