This report summarises population models for arrow squid in the Subantarctic. The models captured the main biological processes adequately. Recruitment estimates were robust to model assumptions and structure. However, absolute estimates of biomass were highly uncertain. The potential for in-season management was tested. Proxies that could be used to compare current relative exploitation rates with past conditions were also investigated; these could be used for hindcasting.

Fisheries stock assessments were undertaken for SCI 1 and SCI 2. The SCI 1 assessment was rejected by the Fisheries New Zealand Deepwater Working Group due to sensitivity to the trawl survey catchability prior. The SCI 2 assessment was accepted, but with a lower quality rating due to unresolved conflicts in data inputs. For SCI 2 current status in 2022 was estimated to be 56% B0 and likely within 47–66% B0. Projections were not carried out with either assessment.

This study used a model of individual eco-physiological response to environmental and climate factors to derive population level outcomes of fish stocks. These simulations were used to investigate how fisheries stock assessments are influenced by climate and bottom-up variability in production parameters. The assessments generally provided unbiased estimates of stock status even though there were annual and decadal fluctuations in all production-related parameters.