Download FAR 2026/37 Relative abundance, size, age structure, and stock status of blue cod from the 2025 survey in Marlborough Sounds

South Island recreational blue cod fisheries are monitored by Fisheries New Zealand using potting surveys. The Marlborough Sounds surveys, carried out every four years, are important for assessing the status of the blue cod stock in this region.

This report describes the results of the random-site blue cod potting survey carried out in Marlborough Sounds in October 2025 and compares these with the results from three previous surveys in 2012, 2017 and 2021. Abundance of blue cod has been low, but relatively stable, throughout the Sounds. Fish are generally small and the population is dominated by males (66–72% male). Fishing mortality has been higher than the target reference point for all surveys, indicating that overfishing is occurring.

The Long Island Marine Reserve has been included in the survey series since 2017. In 2025, blue cod abundance was 4–8-fold greater and mean length was 3–5 cm greater in the marine reserve than in adjacent fished strata in Queen Charlotte Sound, with no clear trend over time. Maud Island Closed Area was surveyed for the first time in 2025. Although mean catch rates were lower than those in Long Island Marine Reserve, abundance, size, and condition in the Maud Island Closed Area were all greater than outside. All blue cod caught in Long Island Marine Reserve and Maud Island Closed Area were released alive.