Download FAR 2025/46 Stock assessment of Chatham Rise orange roughy in 2025

Dunn, M.R.; Datta, S.; Doonan, I.J. (2025). Stock assessment of Chatham Rise orange roughy in 2025. New Zealand Fisheries Assessment Report 2025/46. 59 p.

The orange roughy fishery on Chatham Rise is split into two stock areas. The East & South Chatham Rise stock catch limit was about 80% caught in 2023–24, and the Northwest Chatham Rise stock catch limit was about 18% caught.

The assessment research identified inconsistencies in the acoustic spawning biomass estimates used to track abundance. The cause of this divergence was not resolved, and therefore two alternative indices of abundance were used.

Inconsistent age frequency samples made estimating changes in stock productivity over time less reliable.

The 2025 assessment used a simplified approach where the model fitted only acoustic biomass data. For the East & South Chatham Rise, model runs were also done using acoustic biomass plus age frequency data.

The virgin size of the East & South Chatham Rise stock was estimated to be around 350 000–440 000 t, with stock status in 2024–25 around 8–18% of that initial level. The recruitment after 1980 was estimated to have decreased substantially.

The virgin size of the Northwest Chatham Rise stock was estimated to be around 59 000 t, with stock status in 2024–25 around 35% of that level. In contrast to the East & South Chatham Rise stock, the average productivity for the Northwest Chatham Rise stock was close to the expected level.