26 Jul 2018

Could salmon farming become the new dairy?

From Afternoons, 1:36 pm on 26 July 2018

New Zealand’s half-a-billion-dollar salmon industry could become 35 times bigger and the world’s most sustainable farming practice, an industry head says.

A NZ King Salmon farm in the Tory Channel.

A NZ King Salmon farm in the Tory Channel. Photo: Supplied to RNZ

New Zealand King Salmon, the largest company in the industry, is looking to expand offshore into Cook Strait, and chief executive Grant Rosewarne plans to apply for consent soon. 

It’s a contentious subject , with arguments over the company’s previous attempts to expand making it all the way to the Supreme Court

In the past five years NZ King Salmon declared it had received $500,000 from the Ministry for Primary Industries, $2.4 million from Seafood Innovation - of which the Ministry of Business Innovation and Employment is a "cornerstone investor" and $15,000 from MBIE for pet food research.

In the six months ending December 2017, the company turned a net profit of $15.7m.

For the 2017 financial year NZ King Salmon harvested just more than 7000 tonnes of salmon and had consent to farm 17 hectares in the Sounds.

Big fish, small pond: Expansion plans

One of King Salmon's farms in Tory Strait.

 One of King Salmon's farms in Tory Strait. Photo: RNZ

Mr Rosewarne says the industry has the potential to become as valuable as New Zealand’s dairy industry. 

Part of the growth would come from the company’s own expansion, which has partly been prompted by fish deaths in the company’s current fishing zones. 

King Salmon's chief executive Grant Rosewarne

New Zealand King Salmon's chief executive Grant Rosewarne Photo: Supplied

Record-high temperatures last summer led to the huge stock losses for the company, sending prices soaring nationally and causing problems with disposal.   

Mr Rosewarne says moving to deeper waters would solve the problem. 

“They can die of heat stress and they can die of normal fish diseases as a result of the elevated temperature. 

“So we’ve got 17 surface hectares in the Marlborough sounds and we want to relocate nine of those into deeper, cooler, faster-flowing water,” he says. 

“Last summer, as we all know, was off the charts in terms of water temperature so our fish need  a lower temperature and if we can go into faster-flowing, cooler water that will certainly help. 

They’re also looking to expand offshore into Cook Strait, however. 

“That would be close to our existing infrastructure but it would have the water conditions where we could grow a lot of really good-quality fish. 

“That’s when we could really achieve a scale in excess of the New Zealand dairy industry as regards value. 

“Going offshore enables us to achieve a scale that we can’t currently achieve.”

A different kettle: Fish health

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Photo: Supplied

Another problem with the space the company has available to it means there’s a higher risk of disease and bacteria which could be partly responsible for the high numbers of fish deaths.

The company was censured over its lack of biosecurity controls last year. Mr Rosewarne says the move into the Strait would make that less of a problem. 

“We really want high biosecurity, we’ve never had that in New Zealand because having only 17 surface hectares and only one-and-a-half regions you can’t be biosecure as a salmon farmer. 

“When we go offshore we’re going to apply for enough space so that we can farm in a really strong biosecure way, and for that you need three separate regions.”  

He says sea lice are not a problem for the New Zealand operations either. 

“We farm a unique species, king salmon, there’s only five farmers in the world - four in New Zealand, one overseas - and our species doesn’t get sea lice. 

“It has a mucus layer that repels them.”

Plenty more fish in the sea: Sustainability

Salmon at the High Country Salmon farm.

Salmon at a salmon farm.  Photo: Facebook / High Country Salmon

Mr Rosewarne claims king salmon farming has the potential to be the greenest animal farming practice in New Zealand, if not the world.

“We believe we’ll be able to show we’re the most sustainable way of producing animal protein, probably in New Zealand but perhaps in the world,” he says.

“We already achieve a stunningly good environmental outcome but because of the nature of salmon farming we could basically produce massive value with an environmental footprint which would be difficult to measure it would be so low. 

“A fully stocked salmon farm is only 2 percent fish, it’s 98 percent space. These are a schooling animal, they want to be together, but we provide a massive amount of space because we provide three dimensions, not two.” 

He says one of the company’s largest farms in Waitata Bay has greater biodiversity there than when they started farming. 

“I think we’re the only farming method where there’s more large natural animals in association with the farming than less.” 

He says the New Zealand King Salmon farms do not have the same negative effect on the seafloor as seen in some other salmon farms. 

“That’s what happens if you’ve got a bad operation, if you’ve got a good operation that’s working to world’s best practice you can achieve a stunningly good outcome.” 

That would particularly be true if the company was granted permission to farm offshore, he says. 

“A well-placed salmon farm works well with the nitrogen cycle, so this isn’t a case of going out to sea for dilution, it’s going out to sea to work positively with the nitrogen cycle.” 

Feeding frenzy: Additives and sources


Photo: 123RF

Mr Rosewarne says the fish are fed with a pellet made from protein, fat and carbohydrate. 

“That’s made in Tasmania and Chile, we’d like to make it here but we’re not of a scale that would warrant producing a local feed.” 

He says the protein comes from Peruvian anchovy stocks - one of the largest biomasses in the world which are managed for sustainability, though not through a quota - as well as locally-produced farm animal offcuts. 

“We’re just using the bits that people don’t want to eat, so all the prime cuts we eat but all the rest we don’t … it’s produced to the same standard.”

He says they do not use antibiotics or pesticides. 

“As Kiwis we want to farm to best practice, and we’re one of the few animal husbandry industries that doesn’t use any antibiotics … it’s definitely so in New Zealand that nobody - not just us but nobody - uses any antibiotics.

He said land animals fed with antibiotics did not then transfer the antibiotics to the salmon, because the animals are withheld from slaughter until the antibiotics have passed through the animal’s system. 

“I can guarantee there’s no antibiotics … we test the feed and we know we’ve never had any antibiotics in our feed. 

“The animals that are used as protein sources have none when they’re harvested for human consumption, but then also it goes through a heat treatment process and then it has to be fed to our salmon. 

“So it’s impossible and we’ve never detected any in the history of our salmon company and we’ve been going 30 years.” 

An additive that is fed to the fish is astaxanthin, but Mr Rosewarne says it’s a natural part of the fishes’ diet.
“You can buy it as a health supplement in your local health store,” he says.

Salmon roe - eggs - are pink like the fish because they contain astaxanthin Photo: RNZ / Veronika Meduna

“We try and keep as close to the natural feed level as possible, so we need to put it in there for their health so yes, we put it in their feed to replicate what they get in nature.  

“The pink colour of salmon comes from something called astaxanthin, it’s an antioxidant perhaps 2000 times more powerful than vitamin C, because of that the marine ecosystem has learnt how to preserve it. 

“So it starts off in algae and then they [the algae] grow it mainly in the southern hemisphere to protect themselves from the sun and stop free radical reactions and oxidation, then the krill eat it and they can store it for the same reason. 

“Salmon is one of the few fish that can store it in their bodies, so they’ll store the astaxanthin because it will protect them when they go into freshwater streams, they’ll also put it in their eggs at the end of their life so that their young have much higher fertility and also so that they can survive in a high-oxygen freshwater environment.”