New Zealand’s King Salmon will set aside three farms in Pelorus Strait in Marlborough by next summer, with one earmarked for trials.
It comes after a summer marked by abnormally high fish mortality.
Between December and February, trucks from Havelock and Picton made 160 trips to the Blenheim landfill, dumping 1,269 tonnes of dead fish and waste.
February alone saw 632 tonnes of fish waste dumped, more than seven times the 90 tonnes dumped in February 2021 and more than the 194 tonnes dumped in February 2020.
New Zealand King Salmon chief executive Grant Rosewarne said while the Pelorus sites were suitable for nine months of the year, they were now too hot to farm during the summer.
“What we’ve tried to do in the past is develop better technology, better practices, better ways of raising the fish to reduce their stress so they can tolerate the temperatures and get through the summer. , but we’ve now come to the view that there’s no amount of that, it’s successful, so the safest thing then is to just avoid the summer.”
Rosewarne said it was the first time the company had to close farms due to rising sea temperatures due to climate change.
“I’ve often said that we’re kind of like the canary in the coal mine, when it comes to global warming, we have a cold-water species that’s very sensitive to a change of half a degree or by one degree. This is what we are seeing in the Pelorus and we really hope to work with the government, to get them to mitigate climate change as they have pledged to do.”
While the closures would reduce harvest volume, Rosewarne said lower mortality costs would allow for more stable and predictable harvesting.
New Zealand’s King Salmon recorded a net loss of $55.7 million in fiscal 2022.
The closures of the Pelorus farm would result in an expected decline in production in fiscal years 2023 and 2024 to 5,700 and 6,500 tonnes respectively, with an increase of 200 tonnes expected for 2025.
Rosewarne said the closures would also lead to layoffs, with around 120 positions affected – it had already lost around 59 staff to natural attrition and another 60 positions were yet to be filled.
The situation was a “real tragedy” for the company and its employees and could have been avoided if the company had enough fresh water space for farming, he said.
The outcome of New Zealand King Salmon’s application to build a deep-sea farm in the Cook Strait – called Blue Endeavor – is expected in September.
Rosewarne said the company was optimistic about the future and had embraced the government’s aquaculture strategy to sustainably develop the industry in New Zealand.
“We believe the aquaculture industry could become both New Zealand’s most valuable industry and the greenest primary sector if supported.”
The three farms in Pelorus Sound will be decommissioned and nets removed by next summer, but the enclosures will remain for use as nurseries if Blue Endeavor’s application is successful.