We investigated orange roughy stock assessments for Chatham Rise, part of ORH 3B.

Stock assessments for this region have encountered problems, with models much more optimistic about stock status than suggested by fisheries statistics and some research surveys.

We describe skipper information on orange roughy behaviour and target fishing, the biology of orange roughy with respect to their sensory abilities, and observations of orange roughy responding to objects in the water column and to fishing disturbance.

Investigations of fisheries catch per unit effort found evidence of disturbance, where recent fishing activity reduced catch rates. The disturbance effect was considered useful but was not a “game changer”.

Seasonal trends in sea temperature, primary productivity, weather, and sea state, could be simply described using a “month” variable. Spatial and regime shift models improved the fits to data.

Observed changes in orange roughy age frequency distributions have been poorly fitted in recent stock assessment models, but were better fitted here by models assuming reproduction had dropped to a very low level once the fishery started. One hypothesis that might explain this result is that fishing disturbance reduced reproductive output.

Offshore finfish farming is expanding in New Zealand, but we lack knowledge about how seabed habitats and their species will respond to organic enrichment (in the form of faeces and waste feed) from salmon farms. This report, part of the Environmental Health Measures for Open Ocean Aquaculture project, investigates these impacts through laboratory and field experiments on three species: horse mussels, brachiopods, and scallops. Lab trials tested responses to controlled levels of enrichment, while field trials monitored animals near an operational salmon farm in the Marlborough Sounds.

Key Findings
• Fatty acid tests showed that all species absorbed salmon waste, which affected their nutritional health.
• Breathing rates increased with enrichment in horse mussels and brachiopods, suggesting they were using more energy to survive.
• Changes in gene activity were strong in the lab but weaker in the field, potentially showing early warning signs of stress.
• Some animals developed health issues, including parasites in horse mussels and scallops, and tissue changes possibly linked to changes in their diet or normal variations in living functions.
• Overall, the effects did not cause death, with N. lenticularis showing higher tolerance than the two bivalve species.

The red rock lobster supports the most valuable inshore commercial fishery in New Zealand. This fishery has been managed with catch quotas in nine Quota Management Areas (QMAs), which are usually treated as independent populations or stocks.

The catch quotas are calculated for some QMAs using management procedures (MPs). Given an input, such as catch per unit effort (CPUE), MPs return an output such as Total Allowable Commercial Catch (TACC).

This document describes the operation of the current MPs used to manage New Zealand red rock lobster (Jasus edwardsii) in CRA 7 and CRA 8 for the 2025–26 fishing year. The operation of the MPs for the upcoming 2025–26 fishing year indicated that there should be no change in TACC for CRA 8, but indicated an increase in TACC for CRA 7.

This research reviewed current data and information about marine heatwaves in New Zealand and their potential effects on marine ecosystems and fisheries. A marine heatwave is a prolonged period of warmer-than-usual water. Such events are increasing in frequency and intensity globally. Aotearoa New Zealand (Aotearoa-NZ) has experienced several in the last decade, and marine heatwaves are predicted to become more frequent and intense, and to last for longer, in the future.

Scientific reports from overseas suggest that marine heatwaves could affect both individuals and populations, causing redistributions such as range expansions or contractions, and affect reproductive success and survival of early life stages. In Aotearoa-NZ, spatial redistributions have been observed but whether they were caused by environmental change is unknown or speculative. Fishes may also be impacted by marine heatwaves through ecosystem changes, in particular the distribution and abundance of prey, changes to biogenic habitat, and disease, as much as through direct physiological effects.

We reviewed published information on 32 species or species groups of importance to fisheries in Aotearoa-NZ. Documented evidence of the impact of marine heatwaves in New Zealand were only found for green lipped mussel, snapper, and king (chinook, quinnat) salmon. Some information was found for bluefin tuna, rock lobster, and snapper outside of Aotearoa-NZ. Further international studies documented impacts for some taxonomically related species of oyster, abalone (pāua), and squid.