King Salmon targets 'open ocean' Cook Strait salmon farm

By Pattrick Smellie

Aug. 6 (BusinessDesk) - Marlborough Sounds fish farmer New Zealand King Salmon is targeting construction of the country's first 'open ocean' salmon farm by late 2020.

The company says the consent application it lodged early last month for 'Blue Endeavour' - a farm about six kilometres off D'Urville Island - has been accepted by the Marlborough District Council. Assuming the application is not appealed to the Environment Court, or called-in to the Environmental Protection Authority, that could allow a decision by November.

That would allow construction of a $25-to-$30 million submersible salmon farm capable of producing up to 5,000 tonnes of salmon. That could be in time for it to be in use by November 2020, chief executive Grant Rosewarne told BusinessDesk in an interview at the country's inaugural Open Oceans Symposium in Nelson.

Rosewarne first unveiled King Salmon's aspirations to follow the Norwegian industry into exposed ocean environments and had initially expected it would need to use emerging new technologies to cope with rough ocean conditions.

However, further research had established that conventional fish farming technologies could handle the conditions at the site in Cook Strait.

"There’s a chance to make a quick decision on something that everyone has been asking for for 10 years and we’ve said is difficult, but it turns out it’s within that five-metre wave height that conventional technology works."

He contrasted his firm's approach with Norwegian research concentrating on "these big heavy-duty steel structures costing hundreds of millions of dollars."

"What we’re putting within Cook Strait will produce a less expensive fish than what we’re producing now, mainly because our survival will go up significantly," Rosewarne said.

Warmer than average sea temperatures have raised death rates over summer at the company's Marlborough Sounds facilities. That is particularly where they are not optimally located but are unable to move while Fisheries Minister Stuart Nash grapples with a long-delayed decision on whether to allow the firm to move some of its infrastructure to new sites with better conditions for fish farming.

Today's symposium was organised by the Cawthron Institute, an independent marine science centre.

One speaker, Associate Professor Moninya Roughan, sounded a warning that the Tasman Sea is one of the fastest-warming parts of the world's oceans. That means Australia and New Zealand are both farming salmon - which require low water temperatures - in a climate change hotspot.

To cope with the risk that existing sites become too warm in future, King Salmon is examining other open ocean sites down the east coast of the South Island. They would not be affected by Tasman Sea temperature variations.

Rosewarne also hopes ocean open fish farming will help King Salmon overcome local community objections that have made further development in the Marlborough Sounds all but impossible.

“We anticipate a favourable reaction from our community, as open ocean farming allows the development of positive economic activity, away from communities and recreational activities.

“We hope that successful commercialisation of our open ocean farming vision may decrease our reliance on the in-shore farming model, as part of our ongoing efforts to farm in the most suitable conditions available.”

The Blue Endeavour project is intended eventually to have two farms on-site, producing in a single location the same volume of fish the company currently produces annually at its inshore sites. That is part of a wider strategy to substantially increase production of high-margin king salmon for local and export consumption.

Supporters argue aquaculture, including salmon farming, is more environmentally sustainable than land-based agriculture as a way to produce protein.

The Blue Endeavour offshore site also likely overcomes the problems caused by uneaten salmon feed affecting inshore marine environments.

"It benefits from those cold currents that come up from Antarctica and we think it solves all our problems in terms of temperature, deaths, oxygen and flow," Rosewarne said.

The site derives shelter from most wind directions, other than an 11-degree sliver of northwesterly exposure, which Rosewarne said was "still a worry".

Crews working on the facility would be evacuated during storms.

The symposium heard from leading European and New Zealand researchers who stressed that the operational challenges of open ocean fish-farming may prove as significant as the design challenges to create structures capable of handling severe ocean conditions.

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