Rig nursery grounds were defined and ranked from a review of existing information and a nationwide set net survey of 14 major harbours and estuaries in 2011. Kaipara and Raglan harbours were very important nurseries, followed by Waitemata, Tamaki and Porirua harbours. South Island harbours do not appear to be important rig nurseries. Juvenile snapper and grey mullet were frequent bycatch in North Island estuaries, and were most abundant in the same harbours as rig.
This review of existing information describes the current state of knowledge on soft-sediment marine assemblages around New Zealand; it identifies hotspots of biodiversity; highlights threats to, and the vulnerability of, assemblages; discusses knowledge gaps; and recommends areas or assemblages that could be the subject of directed future research. The review is supported by The Marine Soft Sediment Biodiversity Bibliographic Database which houses over 700 references.
This report describes relationships, patterns and contrasts in benthic species composition, assemblages and habitats, both within and between sites and initial sampling strata across the Challenger Plateau and Chatham Rise. Data used came from four different fauna collection methods: DTIS video; seamount sled; still images taken along the DTIS video; and beam trawls.
The development and retrospective application of a system of trauma classification to all sea lions captured from 1999/00 to 2007/08 is discussed, and results compared across years and between groups (e.g. SLED versus non-SLED captures). A lack of brain examinations in the years before 2006/07, in combination with difficulties in interpreting lesions from frozen cadavers, means that this retrospective review has some limitations.
Rhodolith beds in New Zealand harboured high diversity of associated macroalgae and invertebrates, undescribed taxa as well new records and range extensions of known species. Subtidal beds were investigated, examining structure and physical characteristics at two locations in the Bay of Islands, and characterising two species, Lithothamnion crispatum and Sporolithon durum. Responses of these rhodolith species to environmental stressors were also investigated both in the field and in culture.
This document summarises the observational and research data for southern blue whiting to 2019. Included here are time series of relative abundance from the wide area R.V. Tangaroa acoustic surveys, as well as from local area aggregation industry vessel acoustic surveys, CPUE indices for Bounty Platform and Campbell Island Rise, and trawl survey indices for the Auckland Islands Shelf, Campbell Island Rise, and Pukaki Rise, as well as updated time series of length-at-age and catch-at-age.
This report presents a description of the distribution of the ling (Genypterus blacodes) trawl and longline fisheries on the west coast of the South Island (LIN 7WC), from 1989–90 up to the 2018–19 fishing year. Catch-per-unit-effort analyses of standardised for commercial line fisheries targeting ling and as bycatch in observed trawl fisheries on the west coast of the South Island (LIN 7WC) are also presented
This document summarises the observational and research data for southern blue whiting to 2018. Included here are time series of relative abundance from the wide area R.V. Tangaroa acoustic surveys, as well as from local area aggregation industry vessel acoustic surveys, CPUE indices for Bounty Platform and Campbell Island Rise, and trawl survey indices for the Auckland Islands Shelf, Campbell Island Rise, and Pukaki Rise, as well as updated time series of length-at-age and catch-at-age
This report presents available New Zealand commercial fishery catch-at-age data for hake (Merluccius australis) caught by trawl, and ling (Genypterus blacodes) caught by trawl and longline, up to the 2018–19 fishing year, and bottom trawl survey catch-at-age data sets for both species up to the summer of 2020.
For southern blue whiting on the Bounty Plateau (SBW 6B), a new Harvest Control Rule, HCR2022, was developed that allowed for consecutive years with no acoustic surveys. HCR2022 replaced the previous HCR which required an acoustic survey every year.
This report summarises the stock assessment of hake off the west coast South Island (WCSI) in HAK 7 for the 2021–22 fishing year. The index of abundance was the WCSI trawl survey. Initial spawning stock biomass was estimated as 78 870 t (95% CIs 74 140–84 810) with current status of 39% B0 (95% CIs 30–52% B0). Five-year projections showed that biomass would increase under average recruitment but would remain flat if future recruitments were low and catches were the same as the TACC.
A stock assessment survey of Foveaux Strait oysters (OYU 5) in February 2023 found numbers of commercial-sized, recruit, pre-recruit oysters, and small oysters had decreased by between 44.8% and 52.3% from 2022 numbers. Winter-spring disease mortality is the most likely cause. These decreases cannot be fully explained by fishery and survey data. Summer mortality from Bonamia increased from 5% in 2022 to 9% in 2023. Mostly large oysters died; 70% of oysters are below recruit-size. Spat settlement was high.