Stevens, D.W.; Ballara, S.L.; Maurice, A.; Escobar-Flores, P.C.; Yeoman, J. (2024). Trawl survey of hoki and middle depth species on the Chatham Rise, January 2024 (TAN2401). New Zealand Fisheries Assessment Report 2024/77. 119 p.

The 28th trawl survey in a time series to estimate the abundance of hoki and other species on the Chatham Rise was carried out from 4 January to 3 February 2024. A total of 131 bottom trawls were successfully completed.

The estimated abundance of all hoki was about the same as the estimate from the previous survey in January 2022, while the estimate of juvenile (2 year old) hoki was average for the time series. The estimate of the youngest (1 year old) hoki was one of the lowest in the time series, suggesting this year class (fish born in 2022) was weak. The estimated abundance of hake increased by 26.5% from that in 2022 and was the highest estimate since 2009. The abundance of ling was about the same as in 2022 and the time series for ling shows no overall trend.

Most hoki were aged less than 5 years. Hake and ling ages were broad, with most hake aged between 4 and 13 years and most ling between 3 and 16 years old.

Acoustic data were collected throughout the trawl survey. The acoustic estimate of mesopelagic fish abundance (thought to be an index of the amount of food available to hoki) in 2024 was 13% lower than that in 2022, and below the average for the acoustic time-series (since 2001).