SCW16-Doc00, Preliminary agenda
SPRFMO
This paper compiles the current draft benchmark agenda for the abundance-index sessions. It combines the acoustic-session schedule prepared by IMARPE and IFOP and the CPUE-session agenda developed at the CPUE coordination meeting held on 14 April 2026.
Participants in the acoustic drafting committee included Criscely Lujan, Daniel Ramos, Mariano Gutiérrez, Ignacio Payá, Victor Catasti, and José Zenteno.
Participants in the CPUE coordination meeting included Criscely Lujan, Miriam Geronimo, Erich Diaz, Ignacio Payá, José Zenteno, Sebastián Vásquez, and Niels Hintzen.
Day 1. Preliminary Acoustic Session Agenda
- Start time: 09:00
- Date: Monday, 18 May 2026
- Note: The morning coffee break is scheduled early on Day 1 only. For the rest of the week, the morning coffee break is expected at 10:30.
Opening
| Time | Topic | Presenter |
|---|---|---|
| 09:00-09:20 | Opening Ceremony | Executive President of IMARPE |
| 09:20-09:30 | Official Photo | All participants |
| 09:30-09:45 | Coffee break |
Session 1
| Time | Topic | Presenter |
|---|---|---|
| 09:45-10:05 | Historical review of hydroacoustic survey programs in north-central Chile | V. Catasti (IFOP) |
| 10:05-10:25 | Preliminary results of the 2026 north-central Chile hydroacoustic survey | V. Catasti (IFOP) |
| 10:25-10:45 | Oceanography conditions during the 2026 acoustic survey | J. Letelier (IFOP) |
| 10:45-11:05 | Spatio-temporal modeling of acoustic backscatter (Sa) from the north-central Chile survey using sdmTMB |
I. Payá and V. Catasti (IFOP) |
| 11:05-11:25 | Toward a standardised abundance index for Chilean jack mackerel: spatio-temporal modelling of acoustic survey data in northern Chile | M.G. Pennino, S. Vásquez, N. Alegría, and A. Sepúlveda (INPESCA) |
| 11:25-11:45 | Opportunistic acoustic data collection using the south-central Chilean commercial fleet | N. Alegría (INPESCA) |
| 11:45-12:05 | Review of jack mackerel acoustic assessments conducted in Peru, including SCW16-Doc16 | Carlos Valdes (IMARPE) |
Session 2
| Time | Topic | Presenter |
|---|---|---|
| 12:05-12:25 | Application of sonar systems in Peruvian anchoveta fisheries and potential applicability for jack mackerel in Peru and Chile | Daniel Grados (IMARPE) |
| 12:30-14:00 | Lunch break | |
| 14:00-14:20 | Use of acoustic data collected by fishing vessels for estimating the abundance/biomass of anchovy and Chilean jack mackerel in Peru | M. Gutiérrez (Instituto Humboldt de Investigación Marina y Acuícola) |
Session 3
| Time | Topic | Presenter |
|---|---|---|
| 14:20-15:15 | Examination and/or validation of jack mackerel echograms | All participants |
| 15:15-15:35 | Coffee break | |
| 15:35-16:25 | General discussion | All participants |
| 16:25-17:00 | Technical recommendations | All participants |
Day 2. Preliminary CPUE Session Agenda (SCW16-Doc02)
The Day 2 CPUE session is currently organized as a thematic sequence. Exact time allocations and presenters remain to be confirmed. Background for these discussions is provided in SCW16-Doc02, which summarizes the CPUE coordination discussion and candidate topics for the benchmark session.
The Peruvian delegation has requested time during the CPUE session for SCW16-Doc15, Standardization of catch-per-unit-effort (CPUE) for jack mackerel (2015-2025) in Peruvian national jurisdictional waters (Miran Geronimo and Gersson Roman).
| Order | Topic | Notes |
|---|---|---|
| 1 | Metadata by fleet and country | Review fleet definitions, spatial coverage, observation level, and index construction by country and fishery. |
| 2 | Methods by fleet and country | Compare GLM, spatio-temporal models, GLMMs with spatio-temporal random effects, and latitude-longitude smoothing approaches, including SCW16-Doc10 and SCW16-Doc12. |
| 3 | Peruvian CPUE report | Present and discuss SCW16-Doc15, Standardization of catch-per-unit-effort (CPUE) for jack mackerel (2015-2025) in Peruvian national jurisdictional waters (Miran Geronimo and Gersson Roman). |
| 4 | Comparative analysis and parsimony across candidate indices | Evaluate traditional GLM, spatio-temporal, and environmentally informed approaches and identify the most suitable benchmark candidates, informed by SCW16-Doc03. |
| 5 | Effort-creep review and decision for stock assessment use | Revisit current effort-creep assumptions and consider whether revised treatment is needed for benchmark runs, including SCW16-Doc07. |
| 6 | Catchability-availability blocks by abundance index | Review evidence for temporal or spatial changes in availability, including possible El Niño effects and implications for q blocks. |
| 7 | CPUE weighting factors for stock assessment | Discuss weighting choices and how they affect assessment fits and benchmark comparisons. |
| 8 | Separate versus combined index products for HCR use | Consider whether the benchmark should retain separate series or define a combined CPUE product for OM conditioning and MP inputs. |
Day 3. Recap, Report Drafting, and Biological Inputs
The morning session will be used to recap the Acoustic and CPUE sessions, identify remaining loose ends, and begin drafting the corresponding report sections. The objective is to document decisions, unresolved technical issues, and follow-up tasks while the index discussions are still current.
The afternoon session will begin with a summary of SCW16-Doc01 and its implications for benchmark and MSE development. This will be followed by a review of the biological assumptions used in the assessment and operating-model conditioning, including growth, maturity, natural mortality, weight-at-age, stock structure, and recruitment-productivity assumptions. The discussion should identify options for refining model runs and for defining a compact set of assessment and OM alternatives for further evaluation.
The Peruvian delegation has requested time during the biological-inputs session for SCW16-Doc14, Technical report on the updated length-frequency data for the Peruvian jack mackerel stock (far-north stock) in Peruvian jurisdictional waters (Criscely Luján and Gersson Roman).
Additional Peruvian reports noted for the benchmark workshop are:
- SCW16-Doc13, Length-weight relationship of jack mackerel (Trachurus murphyi) in Peru and its implications for biomass estimation (Sandra Cahuin, Ana Alegre and Marilú Bouchon).
- SCW16-Doc16, Considerations on the use of the jack mackerel acoustic index in Peruvian national jurisdictional waters (Gersson Roman, Sandra Cahuin and Marilú Bouchon).
| Session | Topic | Notes |
|---|---|---|
| Morning | Acoustic and CPUE recap and report drafting | Summarize key conclusions, outstanding questions, and text needed for the workshop report. Include SCW16-Doc11 catch/fishery data quality checks where they affect benchmark inputs or follow-up tasks. |
| Afternoon | SCW16-Doc01 summary and biological inputs | Review assessment simplification results, biological assumptions, and options for refined model runs. Include SCW16-Doc05/JM_Biology, SCW16-Doc13 Peru length-weight, and SCW16-Doc14 Peru length-frequency. |
Day 4. Projections, Recruitment Scenarios, and OM Specifications
Day 4 will advance discussion of assessment-model projections, recruitment scenarios, and operating-model specifications. This should include how projection assumptions connect to benchmark assessment runs, how alternative recruitment histories or productivity regimes should be represented, and how operating-model sets should be structured for MSE testing.
The session should also review MCMC evaluations and any technical constraints that affect their use, including convergence diagnostics, run time, storage, parameterization, and feasibility for candidate assessment and operating-model configurations.
| Session | Topic | Notes |
|---|---|---|
| Morning | Assessment projections and recruitment scenarios | Review projection assumptions, recruitment windows, productivity regimes, and links to benchmark assessment runs. |
| Afternoon | OM specifications and MCMC evaluations | Define candidate OM specifications and document MCMC diagnostics, feasibility, and technical constraints, including SCW16-Doc04. |
Day 5. Final Decisions and Report Adoption
Day 5 will focus on finalizing workshop decisions and completing report drafting. The goal is to agree on recommendations, document any unresolved issues, and adopt the workshop report for consideration by SC14.
| Session | Topic | Notes |
|---|---|---|
| Morning | Final decisions and recommendations | Confirm agreed benchmark inputs, model-run priorities, OM specifications, and follow-up tasks. |
| Afternoon | Report drafting and adoption | Finalize report text and adopt the report for SC14 consideration. |