Most fishing methods catch target and non-target (unwanted) species, and unwanted catch may be returned to the sea in some cases.
Fishers and observers record catches of target and non-target species, and the amount of catch returned to the sea (discards).

Total non-target catch and discards for key species and species groups reported in the hoki, hake, ling, silver warehou, and white warehou (HHLSW) fishery from fishing years 2003 to 2022 were estimated with a statistical model.

Hoki and other target species make up most of the catch in this fishery, and key non-target species inluded javenlinfish, rattails, and sharks.
Gemfish showed a significant increasing trend in the amount of non-target catch reported, and sharks and slickheads showed significant decreasing trends.

The amount of catch that is discarded compared with the target catch is lower for this combined fishery than for other fisheries that are monitored.

Monitoring levels of catch and discards is important for understanding the impact of fishing on the environment.

Two oreo species, black oreo and smooth oreo, are commercially important in New Zealand waters. Oreos are deepwater fish and so are not very productive which means they can be easily over-exploited.

Management is based on setting catch quota for each oreo management area, but some areas have localised fisheries which are assessed separately to avoid over-exploitation.

To assess if catch quotas are sustainable, abundance trends are produced from acoustic surveys and/or catch per unit effort (CPUE) series from the commercial fisheries within a quantitative assessment.

Reductions in fishing effort and quotas have made acoustic surveys too expensive to fund from a levy on catch quotas and CPUE series in several areas have gone from accepted to rejected as a reliable indication of stock abundance trend, so quantitative assessments have been curtailed.

This study considered a range of different assessment methods and their data requirements in anticipation of lower-level monitoring and, for each oreo fishery, presents the monitoring and assessment options.

For two management areas (OEO 3A and OEO 4), acoustic surveys are still considered feasible if redesigned to reduce costs. Quantitative assessments are also considered possible and a method to explicitly consider spatial variation of CPUE within the area is demonstrated in this work as a way to improve the CPUE input data.

For the other main management area (OEO 6), none of the localised areas have sufficient data to continue quantitative assessments and, possibly, insufficient data for any other type of lower-level assessments.

The Marine Ecology Research Group used detailed field surveys to assess the recovery of the inshore coastal ecosystem affected by the cataclysmic 2016 Kaikōura earthquake.

The earthquake caused seismic uplift from 0.5 to 6.4 m along 130 km of coastline and resulted in widespread die-offs of important flora and fauna and permanent losses to critical habitats.

There was much concern for the fate of diverse intertidal and subtidal communities, which include culturally and commercially important fisheries, such as pāua, and other habitat-forming species like bull kelp.

Shore-based and dive surveys tracked the abundance of over 120 marine species at 16 sites for more than six years. Findings depict major physical and ecological changes over time across sites.

The complex dynamics of recovery are described in detail in this report and clearly show that the effects from this disturbance to the Kaikōura coastal ecosystem are both significant and ongoing.

This long-term study is the first of its kind and provides a detailed data set and quantitative baselines that will help inform future coastal management decisions.

The study investigates cryptic mortality (i.e., deaths that are not observed) of seabirds in New Zealand’s trawl fisheries, separately for net captures and warp cable strikes. For net capture-related mortality, the results suggest that, on average, mortality was 2.5 times higher than when only based on observed captures. For warp strikes, estimates varied based on data sources, highlighting the need for tailored data collection due to uncertainties and sparseness in the current dataset.

Acoustic biomass surveys of orange roughy (Hoplostethus atlanticus) in ORH 3B North Chatham Rise spawning grounds, 4–8 July 2021, on FV Amaltal Apollo. Surveys were undertaken on Morgue and Graveyard hills in NWCR and on the Rekohu aggregation in ESCR. The survey was prematurely curtailed due to vessel engine failure. Ancillary biomass estimates for Rekohu and Spawn Plume aggregations were derived from hull-mounted echosounder snapshots undertaken by FV Amaltal Mariner and FV San Waitaki.

This report details an implementation of the Spatially Explicit Fisheries Risk Assessment (SEFRA) framework to seabirds in the New Zealand Exclusive Economic Zone, attempting to quantify the impact of New Zealand commercial fisheries on New Zealand populations of seventy-one seabird species. As part of the project both the biological and fishery input data have been updated, as well as the structure of the model itself.

This survey assessed nutrition content and health claims made on 700 food labels across 16 food categories available for retail sale in 2022 in NZ. Claims were identified then assessed to show: the most commonly used claims, whether they met regulatory requirements in Standard 1.2.7 of the Food Standards Code, and any trends since the last survey in 2016/17. Nutrition Content claims were most commonly made on foods. Health claims were less common but had doubled in popularity compared with the previous survey.

The study summarised diets of top predators in New Zealand waters and estimated the spatial-temporal distribution of many of their prey species caught in inshore fisheries. These were consistent with previous estimates and with existing information and could be used as inputs in other processes such as spatial risk assessment models. Care should be taken for species such as squid or hoki where only the shallow part of their range was included and species groups such as jack mackerel or rattail.

Striped marlin is one of the main target species in the New Zealand gamefish fishery. Professional skippers on charter boats have provided striped marlin catch and effort information in voluntary surveys since 1975. Since 2007 private and charter skippers have provided daily records of billfish fishing. Negative binomial GLMs were used to standardise striped marlin CPUE up to 2021–22. The annual catch of billfish, yellowfin tuna, and mako sharks is described from detailed fishing club records.

New Zealand Gamefish Tagging Programme release and recapture data are updated to include the 3962 fish tagged and 74 fish recaptured during the fishing years 2019–20 to 2021–22. The number of gamefish landed by New Zealand Sport Fishing Council clubs is reported. The combination of data from these sources is used to characterise the recreational catch of billfish, yellowtail kingfish, mako, and blue sharks. It is indicative of recreational catch for tuna and other large shark species.

This project developed a food-web model to explore the potential ecosystem effects of changes to small and medium-sized pelagic fish (including jack mackerels, anchovy, pilchards, sprat, yelloweye mullet, blue mackerel, yellow-tailed scad/kōheru) in the Hauraki Gulf. We found that the response of the ecosystem to changes in the abundances of pelagic fishes depended strongly on the extent to which top predators (seabirds, whales/dolphins, fish) are flexible in their diets.

The commercial eel (longfin, Anguilla dieffenbachii; shortfin, A. australis) monitoring programme captures processor recorded data from individual landings throughout New Zealand on eel catch weights, species composition, size grades, and catch location at the catchment level. This report provides detailed results from the 2018–19 to 2020–21 fishing years and also examines trends in the North Island and South Island time series from 2003–04 to 2020–21.

An analysis of juvenile red rock lobster growth around New Zealand, based on existing length and mark-recapture based growth information, is reported here. The time lag from puerulus settlement to recruitment in stock assessment models is highly likely to be 2–3 years, when this occurs at 30–35 mm tail width (TW). Annual growth increment at 30 mm TW is about 9 mm based on Stewart Island growth information, about 12 mm at Gisborne, and potentially faster along the north coast North Island.