Commercial catch and effort data and fisheries observer records of catch and discards by species were used to estimate the rate and level of non-target catch and discards in the orange roughy and oreo trawl fisheries for fishing years 2002–03 to 2019–20. Estimates were made for broad categories of catch and discards including target species, QMS species, non-QMS fish, and non-QMS invertebrate species, and estimates of annual catch were made for several of the major individual non-target species.

Habitat suitability modelling (HSM) enables prediction of taxon occurrence across unsampled areas by assuming higher likelihood of occurrence where environmental conditions are similar to those where the taxon has been found. This study tests the ability of HSM models developed for Chatham Rise to predict species and community distributions in a neighbouring region, Campbell Plateau. Most models predicted poorly but a Gradient Forest community classification has potential uses for management.

In 2020/2021, 476 study burrows were monitored within the Great Barrier Island/Aotea study area with 67% occupied by breeding pairs and fledgling success 76.8%. Only 3 burrows were detected from 128 transects across the remaining medium-grade habitat and distance sampling models could not be run. However, within core high- and medium-grade habitat above 300 m, distance sampling proved a robust population estimate method resulting in 4336 breeding pairs.

Commercial catch and effort data and fisheries observer records of catch and discards by species were used to estimate the rate and level of non-target catch and discards in the jack mackerel trawl fisheries for the fishing years 2002–03 to 2018–19. Estimates were made for broad categories of catch and discards including target species, QMS species, non-QMS fish, and non-QMS invertebrate species, and estimates of annual catch were made for several of the major individual non-target species.

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.

The effect of projected future temperature and pH on coastal phytoplankton and biogeochemistry was determined in four mesocosm experiments. Warmer temperature had greater impact than lower pH, increasing phytoplankton biomass, altering size and dominant group, and affecting particulate Carbon:Nitrogen and fatty acids. However, zooplankton were largely unaffected, and application of the phytoplankton responses in a model indicated generally positive impacts on green-lipped mussels.

A quantitative dataset of benthic invertebrate occurrences from photographic surveys was used to predict distributions of individual taxa and communities across the south-eastern sector of New Zealand’s Exclusive Economic Zone. Several methods were used to model distributions of individual taxa and whole communities. Most individual models had at least some explanatory and predictive power, while community classifications showed potential for use in environmental management.

A literature review revealed a wide variety of ocean acidification (OA) effects on fish. Tank experiments revealed both positive (growth and survival) and negative effects (metabolic performance and hearing) of OA and elevated temperature on snapper. A snapper population model that adjusted parameters to account for OA and elevated temperature suggested positive and negative outcomes were possible. Given this, further data collection and frequent monitoring to inform management would be prudent.

This study developed a method to assess risk to benthic habitats from fishing, using holothurians on the Chatham Rise as a case study. A spatial population distribution layer was developed. This layer and the bottom-contacting trawl footprint were then used in a Bayesian spatial population model to calculate the biomass trajectory and spatially and temporally explicit impact overlap statistics for the taxon. Species susceptibility was either assumed or estimated within the population model.

The purpose of these guidelines is to inform the sustainable development of open ocean finfish farming in New Zealand by providing robust and practical guidance to minimise and mitigate effects on marine mammals. The guidelines focus on mitigation of interactions through site selection, design, and operation of farm infrastructure through carefully designed monitoring programmes to assess the effectiveness of mitigation measures.

The purpose of these guidelines is to inform the sustainable development of open ocean finfish farming in New Zealand by providing robust and practical guidance to minimise and mitigate effects on seabirds. The guidelines focus on mitigation of interactions through site selection, design, and operation of farm infrastructure through carefully designed monitoring programmes to assess the effectiveness of mitigation measures.

Vector Autoregressive Spatio-Temporal (VAST) models were applied to research trawl survey and environmental data to provide updated information on stock status for seven deepwater sharks. Deepwater sharks were found to be ubiquitous around New Zealand, with each species shown to have a unique distributional pattern. Deepwater shark “hotspots” in New Zealand waters were identified (e.g., Puysegur). There was little evidence to suggest any temporal or spatial changes in distribution or abundance.

In 2019–2020, 458 study burrows were monitored within the Great Barrier Island/Aotea study area with 63.1% occupied by breeding pairs and fledging success was 76.5%. Pre-laying foraging trips by 10 adults were 30 days long on average and highly variable. Birds ranged far to the east, west, and north of Aotea and breeding birds made significantly longer trips than non-breeding birds. Distance sampling estimated there were 3130 breeding black petrels within core medium-grade habitat above 300 m.

This report describes bycatch of non-protected invertebrates from commercial fisheries and research trawls. Over 660 distinct taxa were identified which contribute to the ongoing discovery and taxonomic description of the New Zealand biodiversity. Specimen records and distribution points inform fisheries interactions with non-target benthic invertebrate bycatch and contribute to research on spatial planning and development of ecological risk assessments of fishing impacts on benthic habitats.

To examine the loss of seabirds (cryptic mortality) during a typical pelagic longline fishing trip, seabird ‘surrogates’ were manually attached to longline hooks under controlled conditions during a typical pelagic longline fishing operation. A single bird was attached to each hook in one of three ways. Almost all the surrogates were retained on retrieval of the gear. This study provides information that will permit refinement of scalars for cryptic mortality associated with pelagic longlines.

This report describes observation data from seafloor photographic imagery collected by NIWA’s Deep Towed Imaging System (DTIS) since 2006 that have been re-analysed for occurrences of litter, with emphasis on marine litter. From 169 000 DTIS records around New Zealand, 149 were of marine litter. Each occurrence was located in the original imagery and classified following the United Nation Environment Programme (UNEP) guidelines on remotely observed marine litter.