This report describes work to better understand spatial and temporal patterns in catch and effort data for silver warehou off the east coast of the South Island. Previous catch per unit effort analyses are summarised, and new analyses for the inshore fishery conducted. Association between large research trawl catches and environmental covariates are examined. Recommendations for future stock assessment analyses are then made.

The 13th acoustic survey of southern blue whiting (SBW) on the Campbell Island Rise took place from 28 August to 25 September 2019 aboard RV Tangaroa. Two acoustic snapshots were completed, both detecting three spawning aggregations in the survey area. Observer data collected from the commercial fleet showed spawning occurred from 3–18 September, and from 23–30 September. The biomass estimate of adult SBW was 91 145 t (CV 27%), 6% lower than that from the previous survey in 2016 (97 117 t).

A review of the 2019 stock assessment of hoki was conducted. The review focused on the main data inputs, including the configuration of the commercial fisheries data and structural assumptions of the model. Exploratory modelling was conducted to investigate key model structural assumptions. Recommendations are provided for consideration in the development of the next hoki stock assessment (to be completed in April-May 2021).