Extended blue cod closure remains as fishery pressures persist

Marlborough Sounds blue cod remain under pressure, with the latest survey indicating low fish abundance and a high likelihood of overfishing, according to Fisheries New Zealand.

The annual closed season for blue cod in the Marlborough Sounds began on 1 September and runs until the end of 10 January. The extension beyond the traditional 19 December reopening was introduced last year.

Fisheries New Zealand Director Fisheries Management, Emma Taylor, says the most recent potting survey was conducted in October 2025, before the extended closure was implemented.

"The 2025 results indicated that, while trends differ by area, abundance of blue cod was low, and overfishing was very likely to be occurring in the Marlborough Sounds."

The full survey results are expected to be publicly available by the end of September.

Emma says the findings are consistent with previous surveys that led to the extended closed season and prompted consideration of additional measures to improve the health of the fishery.

Fisheries New Zealand is also investigating other ways to improve the productivity and resilience of the Marlborough Sounds blue cod fishery.

One area of focus is the mortality rate of undersize blue cod returned to the water, which has been identified as a potentially significant factor affecting fish stocks.

To better understand the issue, Fisheries New Zealand has commissioned Earth Sciences New Zealand, formerly NIWA, to carry out a research survey on release mortality.

The survey has been running since May and fishers can contribute by recording information about blue cod they return to the sea using the Citizen Science App, available on iOS and Android devices.

Paper forms are also available from Marlborough fishing shops and at boat ramps in Waikawa, Picton and Havelock when Earth Sciences staff are present, generally on suitable fishing days.

The survey will continue through the closed season. Data collected from accidentally caught and released blue cod during this period is expected to help improve future fishery management.

More information, including advice on avoiding blue cod catches during the closed season and returning fish safely to the water, is available at www.mpi.govt.nz/marlborough-blue-cod.