Fisheries New Zealand commissioned a report focused on benthic effects of open ocean aquaculture overseas. This included case studies from Norway regarding water quality effects (Keeley 2020). A technical working group was then formed to discuss issues and develop guidelines for benthic and water column effects, given the range of options available for monitoring and management of these effects. Iwi and stakeholders were given the opportunity to provide feedback on the first draft.

Catch at-age sampling of TAR 1, 2, 3 , 5, 7 & 8 bottom trawl fisheries during the 2018–19 and 2019–20 fishing years suggest tarakihi comprise two stocks, an east coast stock and a west coast stock. Patterns in year class strength suggest that recruitment to the east coast stock largely occurs south of Banks Peninsula. Recruits progressively move northwards as they mature. West coast stock recruitment appears to originate from Tasman/Golden bays; fish move both north and south as they mature.

This research characterised the catch and biological data from the New Zealand packhorse rock lobster fishery. In addition, a biomass dynamics stock assessment model was developed based on estimates of historical catch and CPUE. This model suggested a stock that was initially heavily fished to a low level in the 1980s, then increased rapidly during the 1990s, and has plateaued at levels well above BMSY since the mid-2000s.

Geostatistical models were used to estimate cockle abundance for 12 sites in the 2019–20 northern bivalve survey. Estimates often had greater precision than the sampling-based estimator, and fine-scale predictions reproduced sampling observations. Nevertheless, results were sensitive to model settings and site configuration. Spatio-temporal models accounting for earlier surveys also improved precision in population estimates, except for sites where cockle beds shifted between years.

Age distributions were estimated for orange roughy sampled from the main Cook Canyon spawning aggregation in 2019 and 2020 and from Cook Canyon Pinnacle in 2020. In 2019, Cook Canyon Plume was dominated by fish between 30 to 65 years old, but with several fish over 100 years old. In 2020, age compositions were similar between strata, with most fish ranging from 30 to 55 years old, with few fish greater than 100 years old. The Plume contained slightly older fish on average than the Pinnacle.