This report presents the results from the 16th inshore trawl survey in a time series started in 1992 along the west coast of the South Island, from Farewell Spit to the Haast River mouth, and in Tasman Bay and Golden Bay.

 

The survey covers depths from 20 to 400 m (core strata) and surveys many species but is mainly focused on giant stargazer, red cod, red gurnard, spiny dogfish, and tarakihi. Since 2017, two additional strata have been surveyed in 10–20 m in Tasman Bay and Golden Bay to cover the full distribution of snapper in the geographic area.

 

Data collected include length, weight, and maturity data for selected species, and collection of otoliths (fish ear stones) of the key species for ageing. The trawl survey provides time series of relative biomass estimates and age, length, and maturity stage information used for stock assessments and fisheries management advice for key inshore species.

 

In 2023, 58 phase one stations were successfully completed in the core strata and another six were carried out in strata 20 and 21. Four phase two stations were completed to reduce the coefficient of variation for spiny dogfish and snapper.

 

Biomass estimates (in tonnes) for the target species in the core strata were: giant stargazer, 915 t; red gurnard, 1498 t; red cod, 69 t; snapper, 3633 t; spiny dogfish, 3043 t; and tarakihi, 493 t.

 

The snapper biomass (core strata plus the 10–20 m strata) was the highest ever in the time series and nearly triple that from the previous survey in 2021, with most fish 20 years or younger. Juvenile snapper were caught mostly in the 10–20 m strata. These strata provide important information on future recruitment and contain a variable proportion of the adult population.

 

A catchability analysis of the survey indicates that the survey can be considered representative of the time series.

Document date
Tuesday, 13 February 2024

Document type
V 1.3

File format
Adobe PDF

File size
6.7 MB

Reference number
2024/06

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FAR: 2024/06;
ISSN: 1179-5352;
ISBN: 978-1-991120-81-6;
AUTHOR: MacGibbon, D.J.; Walsh, C.; Buckthought, D. Bian, R.;

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