Applying the management strategy evaluation tool openMSE to the Antarctic krill fishery case

The openMSE open-source project offers a framework and tools for performing Management Strategy Evaluation (MSE) and has been used for dozens of species. Antarctic krill management is currently informed from the Generalized Yield Model, and its implementation in the Grym R package. Here we develop the parameterisations and modifications required to approximate Grym krill modelling within openMSE. We perform modelling for a range of scenarios using both the Grym and our openMSE analogue for comparison. The implemented openMSE-Grym approximation produces estimates of γ_p that are either identical or within a range of 0.75 - 2.5 percentage points lower than those obtained under the Grym’s base-case implementation, with the different temporal resolution of the modelling being a main driver of differences. The work here offers the possibility of MSE for krill through openMSE, which provides substantive flexibility, access to a large toolset, and a common transparent approach. Further, plans to incorporate finer-scale, sub-annual, time resolution into openMSE will permit even closer approximation with Grym.