To address concerns that observer sampling for catch composition in the JMA 7 trawl fishery may be biased if samples are gathered only at the start of processing, observers took up to four sub-samples of jack mackerel during the processing of catches and recorded additional information about the sub-sampling process. Differences in species proportions and the mean size of fish were not related to the time during processing at which the sub-samples were taken.

To develop an assessment approach using spatially explicit catch, abundance, and harvest rate estimates for inshore finfish stocks, spatial patterns of relative density were estimated fitting research vessel survey data to environmental covariates using Generalised Additive Models for nine species. The density estimates were converted to absolute abundance using estimates of research survey catching efficiency. In addition, the eSAFE method used the relative density estimates directly.

A fishery characterisation and stock assessment have been undertaken and accepted for SCI 3. A three stock model was developed, based on previous studies. A range of sensitivities were examined, but models were broadly consistent, suggesting SSB is currently around 65–100% SSB0. Projections out to 2025 suggested that SSB would remain well above 40% SSB0 with future catches up to 20% higher than the current TACC.

This report presents analyses of the potential impacts of climate change on selected New Zealand finish. Historical research vessel catch data, likelihood clustering, and New Zealand Earth Systems Model hindcasts and forecasts, were used to estimate future redistribution of fish assemblages. A simulation model was used to examine the possible influence of climate change on stationary stock productivity.

Spatial movements of species are expected under climate change. For New Zealand fish species in the Quota Management System, this report describes depth and temperature distribution and length frequencies from research trawl catches, and a history of spatial distribution from commercial fishery catches. Some spatial patterns were likely artefacts from changes in catch reporting, whereas others seemed plausible and some were corroborated. Change was most pronounced off the South Island.