Using VAST (vector autoregressive spatio–temporal) models to predict spatio–temporal changes in macrourid by-catch in the Ross Sea region Antarctic toothfish (Dissostichus mawsoni) fishery: Methods and preliminary results

In this paper, we present methods developed to predict spatio-temporal changes in macrourid bycatch in the Ross Sea region Antarctic toothfish (Dissostichus mawsoni) fishery and some preliminary results. Our methods rely on VAST (vector autoregressive spatio-temporal) models fitted to catch rate data of Macrourus whitsoni and M. caml collected by observers. These VAST models are planned to be used in a package of research to be presented to WG-FSA, to explore the combined effect of bycatch mortality and predation release on macrourids in the Ross Sea region, and to suggest ways to manage bycatch in the Ross Sea region given the spatio-temporal patterns in the two macrourid species. We look for support for the VAST modelling approach for bycatch research from WG-SAM and propose there be time on the agenda at WG-FSA-2022 to further discuss options for managing bycatch of these species in the Ross Sea region.