'A gym for fish' - Scientists measure performance of salmon to learn how to farm effectively

Source: 1News

Scientists in Nelson studying king salmon have made a surprising discovery - the fish seem to have their own individual needs and behaviours just like humans do.

Fish at Nelson's Cawthron Institute are put to the test, scientists looking at how efficiently the salmon turn feed into fillet.

“It’s a gym for fish. We put them on the treadmill and see how well they perform, and that’s just like measuring that on an athlete, right? So we’re measuring their oxygen consumption, we’re measuring their metabolic rate, and trying to understand how much energy are they using,” says Cawthron Institute’s, Serean Adams.

Food is almost two thirds of the cost of farming salmon.

“If you have an efficient fish then you’re actually using less feed to produce a kilo of fish. The impacts of that means that it’s good for the environment as well,” says aquaculture scientist, Jane Symonds.

Tiny ceramic beads are put in the feed so when the salmon are temporarily anaesthetised and x-rayed after eating, scientists can tell how much each has consumed.

The varied results are surprising scientists.

“It’s a bit like an all-you-can-eat buffet, where you get those people that, you know, just have one plate and that’s enough, and then others go and have three plates, and so we have fish like that as well,” Symonds says.

While one fish might only eat twenty pellets per meal, some inhale 300.

“And understanding what the range is for a healthy population of fish so we know when it gets out of range and we can say look you need to put your fish on a diet,” Adams says.

The scientists hope future research will create a more efficient fish population, to help them cope with more extreme elements, as farming expands further out to sea.

“We might get them in the gym, get them really fit, so that when they are going out into the open ocean they’re ready for that environment,” Adams says.