- Objectives
- Build upon the previous collaborative work and continue to develop dorado stock assessment methodologies
- Expand the MSE for dorado by evaluating alternative reference points and harvest control rules.
- Background
- Some Members of the IATTC are interested in obtaining MSC certification for their dorado fisheries, and have requested guidance in developing of reference points (RPs) and harvest control rules (HCRs).
- Other Members are seeking guidance regarding data collection, research efforts, and management options
- Relevance for management
- The results of the project, such as alternative estimates of stock status (e.g. assessments, depletion estimator), reference points, and harvest control rules, could be used by the Commission, or by individual Members, in developing, adopting, and subsequently modifying as necessary, a harvest strategy for dorado.
- Duration
- 6 months, starting January 2019
- Workplan and status
- Alternative RPs and HCRs will be evaluated, and their respective advantages and disadvantages will be discussed, to assist Members considering the implementation of reference points and harvest control rules for dorado.
- The performance of alternative assessment methods, HCRs and RPs will be evaluated by simulation methods, using Stock Synthesis. Candidates for the different components of a management strategy (data, assessment method, HCR, RPs) and the performance measures to judge such strategies will be identified.
- Options will include minimum size limits, precautionary lower CPUE levels that would trigger management actions. Alternative RPs will be developed with yield-per-recruit considerations, as well as alternative expected reductions of recruitment without fishing (R0) and unfished biomass (B0).
- External collaborators
- Work to be carried out by external contractor
- Deliverables
- List of candidate RPs and HCRs to be tested using a management strategy evaluation (MSE) framework; • Simulation study to evaluate candidate HCRs and RPs;
Written report summarizing the results; and presentation at SAC-10.
- Updated date: 01 May 2019
- Progress summary for the reporting period
- A review of potential reference points (RPs) and harvest control rules (HCRs) for dorado in the South EPO was conducted, using updated catch, CPUE, and size-composition data.
- Challenges and key lessons learnt
- This simulation study was delayed to accommodate work required for the bigeye assessment review in March 2019.
- The lack of stock assessments for dorado in the South EPO is problematic, since determining RPs and HCRs depends on assessment estimates.
- Obtaining complete and timely data is critical, given the dynamics of dorado and of the fishery, but this is not always easy.
- SAC-10-11 Potential reference points and harvest control rules for dorado in the EPO