Preliminary closed-loop simulations for northeast porbeagle: Illustrating the efficacy of alternative management procedures and assessment frequency
Porbeagle shark populations are listed on CITES Appendix 2 so it may be hard to obtain indices of abundance for stock assessment. We conduct a preliminary series of closed-loop simulations to determine yield, conservation, and variability in effort performance of different Management Procedures (MPs) and assessment frequency. We test 106 MPs with different data requirements. We condition Operating Models, on catch and CPUE time series of the northeast stock using life history and other parameters from the 2020 ICCAT assessment for the western porbeagle stock. There are many MPs that could meet status reference points equivalent to CITES listing criteria as well as BMSY and FMSY criteria; within those, there is a large variability in catch performance. The effect of assessment frequency on performance depends on the metric and on the MP. Future refinements of OMs are needed to provide a more challenging set of hypotheses to test MP performance and to match the properties of the eastern porbeagle stock and fishery closely.