How to get salmon out of hot water

Scientists are looking for ways to adapt salmon fisheries for climate change. In this episode we talk to UK-born Dr Jane Symonds about how to save the industry from mass fish die-offs. Produced by Kadambari RaghukumarResearchers at Nelson's Cawthron Institute are working to help Marlborough's salmon industry survive the challenges of climate change.This week Voices visited the institute's fin fish breeding lab, where large tubs contain salmon that are being monitored for growth and feeding habits. Sea water is pumped into these tubs from the ocean that's just a few metres outside the aquaculture park at Cawthron.Jane Symonds is an expert in genetics and selective breeding, but working with fish wasn't exactly something she'd foreseen growing up in a landlocked part of the UK. Listen to Voices"I grew up in industrial Northern England in a mining town in Yorkshire, and never really saw the sea."Once she came to Christchurch that all changed."I suddenly realised there's a whole beautiful world out there and having the sea on your doorstep was fantastic."This started her on her path to genetics and aquaculture, she says.Jane's been at Cawthron for about five years now. She's part of a global team of experts, with nearly 300 scientists from 35 different countries.New Zealand's salmon industry in Marlborough is based on farming a cold-water species of salmon that's susceptible to even half a degree or one degree change in water temperature. It faces huge challenges as a result of climate change and global warming."We've been selecting for these traits like growth and product quality. How can we now look at what we need to do to make our stocks resilient to climate change? And so that's an important question as part of the industry adaptation to what's coming or what's happening now because they're already being impacted," says Jane.To give a sense of the scale of that impact, last year was the first time New Zealand's King Salmon had to close some of its farms because of higher ocean temperatures.That caused a net loss of $55.7 for the company in the 2022 financial year, with thousands of tons of fish having to be dumped in nearby Blenheim's landfill.The team at Cawthron have set up a temperature challenge working with New Zealand King Salmon and their breeding program to test salmon.Early results are promising, Jane says."There is a genetic component to temperature tolerance. It's got a good heritability you can breed from it."The scientists test the salmon by warming water to a point that is sub-optimal for the salmon, she says…Go to this episode on rnz.co.nz for more details