Download FAR 2024/50 Length and age composition of commercial snapper landings in SNA 8, 2022-23

Snapper is New Zealand’s most important commercial inshore fish species.
NIWA conducted a research study to find out the size and age of snapper from the SNA 8 stock, which covers the west coast of New Zealand North Island.
In total, 6000 snapper were measured and 600 otolith pairs (fish ear stones) were collected for ageing from land-based sampling of 15 commercial bottom trawl catch landings at a fishing company in northern SNA 8, during October 2022 to February 2023.
The current study provides information that covers a 30 year time series of research. This is used for assessments and fisheries management advice for snapper stocks.

The average age of snapper landed by bottom trawl in 2022–23 was 6.7 years, the second highest recorded, meaning substantial improvement in the fishery. The average length was low at 35.5 cm due to slow growth rates as the snapper population increases.

A trial of a new fishing method, modular harvest system, was also sampled with over 2000 snapper measured and 69 otolith pairs collected from six catch landings, also in northern SNA 8. The average length and age estimates of these snapper were 39.4 cm and 8.8 years.

A southern SNA 8 bottom trawl fishery also operated in 2022–23. Nine landings were sampled and 540 otolith pairs were collected. The average length and age estimates from these snapper were 36.6 cm and 6.9 years.

SNA 8 south landings had a higher average size and weight for a given age (therefore faster growth) compared with SNA 8 north; this suggests that SNA 8 south may be mixture of both SNA 8 north and SNA 7 (Tasman Bay/Golden Bay).