Developing the two-area population CASAL model for stock assessment of Antarctic toothfish (Dissostichus mawsoni) at the Subarea 48.6

A preliminary integrated stock assessment model with considering migration between northern and southern research blocks (two-area population model) was constructed for Dissostichus mawsoni at the Subarea 48.6, using the latest data collected from blocks 2 – 5. The model is identical in scenarios about IUU fishing and depredation, and biological parameters from the model in WG-FSA-2021/49 to focus considering spatial structure by expanding to two-area model. The two-area population model could not run completely with indicating error message during model checking process at the beginning of the CASAL running.