This week Seafood New Zealand’s General Manager Deepwater Aaron Irving shares an update on a recent milestone – the 2025 hoki acoustic biomass survey.  

It was a great moment when I got the call from Mark Cooksley, skipper of FV Rakaia, confirming that the survey of spawning hoki in HOK 1 – the Cook Strait and East Coast South Island – had been successfully completed. 

Our hoki fishery is so important to our sector, and we work on many different levels to make sure stocks remain healthy. It was the first whitefish fishery in the world to be certified by the Marine Stewardship Council, back in 2001, so we’ve now held that status for over 20 years.  

The acoustic biomass survey was initiated by us (industry), with the scientific expertise of Earth Sciences New Zealand (formerly NIWA) making sure it was delivered through a robust and rigorous programme. The data collected will play an important role in shaping future fisheries management decisions for this fishery. 

Over the course of seven voyages, FV Rakaia completed: 

  • Six snapshots in the Cook Strait, covering all designated strata. 
  • Four snapshots in Conway Trough and Pegasus Canyon on the East Coast South Island. 

All primary survey objectives were met, including: 

  • Estimating spawning biomass using the FV Rakaia hull-mounted acoustic ES80 system. 
  • Conducting targeted trawls for species identification and biological sampling. 
  • Collecting otoliths and other data to support age structure analysis (the same observer was on board for the entire survey). 

The survey was timed to align with peak spawning periods, and it was confirmed that fish were indeed caught when spawning.

The FV Rakaia did a really great job, taking advantage of favourable weather windows, and they even completed the survey ahead of schedule.  

During the survey, we successfully crossed live via video link to the Seafood New Zealand conference – giving delegates a glimpse of the survey happening out on the water.  

So, what did we learn?  

The results still need to be formally evaluated and peer-reviewed but initial feedback from Earth Sciences NZ acoustic scientist Pablo Escobar-Flores suggests that biomass levels in Cook Strait may be higher than in 2023. Reports from Mark were positive too: the Cook Strait was looking good, with large marks, and plenty of big fish. 

The East Coast South Island was also looking promising, with the surveyors noticing good separation of males at the top of Pegasus Canyon and females at the bottom. Also notable was the large size of the females and the number running ripe and carrying roe. 

It was wonderful to see this survey come together so well, not only in terms of meeting survey objectives, but in exceeding them. A true collaborative effort and we are grateful to all involved. 

Of course, while this survey work was underway, the hoki season itself was in full swing (running from late June to early September). This season has reflected our ongoing commitment to maintaining a healthy fishery – it’s been a bountiful, sustainable harvest. 

If you’re keen to see a hoki vessel in action, check out the photo essay in the Spring issue of the Seafood New Zealand magazine (out now). Nelson-based photographer Steve Hussey joined Resolution II owner-operator Chase Saunders-Loder to capture some of the moments that make hoki season special. The first trip was battered by bad weather, making it nearly impossible to stand, let alone shoot. But a second trip delivered – and the images really do show the hard work and heart of this fishery.  

There’s no doubt the sector works incredibly hard to make sure the hoki fishery remains one of New Zealand’s real success stories. From the scientists and skippers to the crews and observers – everyone plays a role. As we await the full analysis of the survey, the feedback so far is encouraging. Hoki truly is a story of sustainability, one we’re committed to carrying forward for generations.