Next Chapter For Open Ocean Aquaculture Research

A Plant & Food Research programme which aims to develop a more climate resilient and sustainable aquaculture system for the seafood industry has been given approval to progress trials to the next stage.

A resource consent has been granted by the Environmental Protection Authority for the Crown Research Institute to conduct small-scale trials of an open ocean aquaculture system prototype six kilometers off the coastline of Rangitoto ki te Tonga D'Urville Island at the top of the South Island’s Marlborough Sounds.

In 2016 Plant & Food Research’s expert Seafood Production group began working on a concept of developing a low impact, open-ocean mobile aquaculture system designed around the needs of the fish. The aim is to create a system that can move around the ocean, so fish can experience the best water temperatures, currents and water quality year-round. Technology is being developed to enable the mobile system to be monitored and operated remotely from land.

Whakapōhewa ki ahumoana - Re-imagining Aquaculture programme leader, Dr Suzy Black, says a mobile system has the potential to increase resilience to warming sea temperatures, address the growing demand for sustainably produced seafood and expand finfish aquaculture production capacity in Aotearoa New Zealand whilst reducing pressure on inshore, coastal areas.

As a protein source, farmed fish in New Zealand sits at the low end of the scale when it comes to its carbon footprint, well below most terrestrial grown forms of animal protein. Dr Black says moving aquaculture production off-shore and into the open ocean presents an opportunity to create an even more sustainable system for the seafood industry with a lighter environmental footprint.

Over the last seven years, the team has developed and refined small-scale prototype fish enclosures for the system. Utilising consented mooring installations in Te Tai-o-Aorere Tasman Bay, they’ve been able to study and test the performance of different prototype shapes and sizes to make sure the environment they’ve created is right for the fish. No fish were involved in these trials, which were focused on fine tuning the system.

Dr Suzy Black says the next stage of this work requires trials to be done slightly further offshore, with the prototype housing small numbers of fish. The resource consent granted by the Environmental Protection Authority allows this research to be undertaken on an existing marine farm site that had already been consented for mussel farming aquaculture activity. Compared to earlier work in Tasman Bay, the new site will offer a higher energy ocean environment, with bigger waves and stronger currents, which is an important step towards testing the system in the open ocean conditions it has been designed for.

“This is a really exciting next step for the project and for seafood production research in general – we're building on the knowledge we have about near-shore aquaculture and making it more sustainable for the ocean,” says Dr Black.

The research programme involves slowly increasing the size of the prototype as the trial phases progress. Dr Black says their initial work would involve an enclosure up to 15 meters long and 3-4 metres in diameter. This would hold small numbers of fish; about 700 snapper or 1000 chinook salmon, with a multidisciplinary team of scientists using underwater cameras and other technology to monitor fish health and behavior as well as water flow and temperature.

“Environmental conditions would be closely monitored before, during and after the trials with the system intentionally stocked at much lower densities than a commercial operation,“ says Dr Black.

The Whakapōhewa ki ahumoana - Re-imagining Aquaculture research programme is funded by the Ministry of Business, Innovation and Employment Endeavour Fund and aligns with the Government’s Aquaculture Strategy, which identifies open ocean aquaculture as a key opportunity for sustainable growth.

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