The third Workshop on Guidelines for Management Strategy Evaluations (WGMSE3)

This workshop is the third in a series of workshops on guidelines for developing Management Strategy Evaluations (MSEs) within ICES, and was intended to explore some of the issues that arose out of workshops that actually developed MSEs for a range of ICES stocks since the second MSE guidelines workshop was held in early 2019. It is intended that results and conclusions herein be used to update the guidelines for conducting MSEs within ICES further.In addition to reviewing existing work, new analyses were prepared especially for this workshop under TORs c (risk and uncertainty), d (more efficient tuning in MSEs) and e (shortcut vs. full MSEs). TOR a covered reference points, and this workshop proposed a framework for calculat-ing reference points from simulation models used in MSEs when an MSE is conducted for a stock. TOR b considered how to handle alternative operating models when reporting results from MSEs, and the workshop made two proposals for how this could be done based on approaches used in other fora where MSEs are developed routinely. Under TOR c, some ideas were put forward based on comparing risk to an unfished scenario such that the inclusion of additional (realistic) uncertainty was not unduly penalised, and could be used to deal with the situation (e.g. for short-lived species) where risk in an unfished scenario was already close to or greater than 5%. There were several proposals for increasing the efficiency of tuning in MSEs under TOR d, particularly when computation time was a factor (e.g. when full MSEs have relatively complex analytical assessments imbedded in the management procedure being evaluated). These were based both on statistical techniques, and a method for identifying the Pareto-optimal solutions that focuses on trade-offs among competing objectives. TOR e (shortcut vs. full MSEs) was the most contentious, but nevertheless useful because it made out the way harvest control rule eval-uations (and more recently full MSEs) conducted in ICES compared to MSE approaches else-where more clearly evident, and highlighted alternative interpretations of the shortcut method. There was discussion of the pros and cons of the full and shortcut methods, including alternative views of how some of the shortcomings in each could be addressed.Several recommendations are made, including a dedicated workshop on reference points, con-sideration of more flexible MSE approaches (such as developing empirical management proce-dures), improving communication between scientists, managers and stakeholders when devel-oping MSEs, and a further MSE guidelines workshop that includes consideration of when per-formance of the HCR/management strategy is not as intended, under both the full and shortcut MSE approaches, as indicated by the results from the simulations.