Download FAR 2025/38 Length and age composition of commercial trevally landings in TRE 7, 2022 – 23 and 2023 – 24

This project estimated the size and age of trevally caught in the commercial bottom trawl and modular harvest system bottom trawl fishery along the west coast of New Zealand (TRE 7 quota management area) during the 2022–23 and 2023–24 fishing years.

Samples were collected from four key areas: Ninety Mile Beach; Kaipara-Manukau; North Taranaki Bight; and South Taranaki Bight, to better understand the health of the fish population.

Over 5000 fish were measured, and more than 3200 were aged using their ear bones (otoliths), making this the most detailed study of the TRE 7 fishery to date.

The results showed clear differences between regions. Fish from Ninety Mile Beach were mostly small and young, while South Taranaki Bight had the largest and oldest fish, including some over 20 years old. Kaipara-Manukau and North Taranaki Bight had a mix of sizes and ages, with some fish also reaching over 20 years.

Overall, the average size and age of trevally slightly decreased during the 2022–23 and 2023–24 fishing years compared to previous sampling years due to more young fish being caught, but the presence of strong year classes and older fish is promising. These results are an important input for quantitative stock assessments for TRE 7.