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.

The Hauraki Gulf/Tīkapa Moana has declining health indicators. This review looks at the marine restoration potential in the gulf, with a particular focus on biogenic habitats. Terminology and frameworks used in the marine restoration literature are summarised, and the gulf’s past and present environmental history reviewed. Most biogenic habitats show loss, except mangroves. Knowledge gaps are highlighted, and suggestions are made for future research and management work.

This report describes the results of a 3-week towed-camera survey of the Campbell Plateau seabed in May–June 2020, following a similar survey on the Chatham Rise in 2016. The aim of the survey was to collect quantitative data for benthic invertebrates in a region of importance for commercial fishing, to develop, test, and improve distribution models for key taxa. The report provides preliminary descriptions of the seabed habitats and fauna encountered along the 82 transects completed.

A machine learning algorithm was developed to analyse underwater videos and to detect the presence of macroalgae. Three habitat-forming algae Ecklonia radiata, Lessonia variegate, and Carpophyllum spp. were successfully identified. The machine learning models can be readily applied to ongoing monitoring programmes to rapidly determine and map the distributions of key macroalgal indicator species along coastlines. Monitoring data are critical to documenting changes in our coastal communities.

This report documents activities, timing, samples, and data collected during the two-week survey in August 2020 to continue the Chatham Rise seamount recovery survey series. The survey used primarily a towed camera system with high definition digital video and still cameras. It focused on the Graveyard seamounts (55 camera transects), but survey work was carried out also on seamounts in the Andes area (24 camera transects, 3 epibenthic sled tows), and Epilogue Seamount (1 camera transect).

This study, conducted in stages over four years, synthesises available information on CO2 and climate-induced changes that affect the New Zealand region and our fisheries. The report reviews the known implications of these changes to the physical and oceanographic system in the coming decades, the state-of-knowledge of how specific fisheries may be affected and, where known, combines this information to determine potential risks to these fisheries.

The spatial analysis of bottom-contacting trawl effort by commercial trawlers within the New Zealand Territorial Sea and 200 n. mile Exclusive Economic Zone (TS+EEZ), in waters open to trawling down to 1600 m depths, is presented in this report, for different time periods during the 1990–2019 fishing years, based on available data. Separate summaries are presented for inshore and deepwater fisheries. A summary of shellfish dredging is also included.

The extent of the bottom-contacting trawl footprint in New Zealand waters open to trawling is updated by this report to include the 2018 (1 October 2017 to 30 September 2018) fishing year, where data are available for the commercial inshore (fishing years 2008–2018) and deepwater trawl fisheries (1990–2018). Effort data for other bottom-contacting fishing methods, Danish seine and shellfish dredge, are also summarised by fishery, for 1990 to 2018 (1989–90 to 2017–18).

This report provides information on zooplankton distributions in the Southern Ocean based on sampling by the Continuous Plankton Recorder Survey, including from New Zealand research and fishing vessels. Statistical models were used to examine the spatial and seasonal distribution of key groups of zooplankton including copepods, euphausiids and pteropods, and to investigate long-term changes in their abundances. Characteristic zooplankton communities in the Southern Ocean were also identified.

This feasibility assessment considers passive acoustic monitoring systems, using the echolocation and communication clicks of the Hector’s dolphins to estimate their location within the water column, and therefore the proximity to demersal trawl fishing equipment. The study examines different array and localisation tracking concepts, possible detection ranges, and installation locations for hydrophones using theoretical simulations

The 2016 Kaikōura earthquake caused extensive uplift along the north-eastern coastline of the South Island of New Zealand. The disturbance resulted in damage to rocky reefs and widespread mortality of marine organisms, including important taonga and habitat-forming species such as pāua and bull kelp. This report describes the results of nearshore surveys at long-term monitoring sites between 2.5 and 3.5 years after the earthquake to assess the trajectories of recovery of rocky reef communities