“Bodybuilding fish” could have a key role in boosting the world’s seafood supply, with new research showing that exercise can help fish grow to marketable sizes much faster.
Key points:
- An exercise training regime helps fish grow faster, according to the new analysis
- Fish experienced the most benefits if they were swum at a speed of two body lengths per second
- Researchers are now looking to work with the aquaculture industry to help meet growing demand for fish
Already, aquaculture is the world’s fastest growing agri-food sector, producing more than half of all fish for human consumption.
But with the world’s population tipped to reach 8.5 billion by 2030, a Murdoch University study has found that keeping fish fitter could help speed up supply to meet growing demand.
Like ‘going for a mild jog’
Researchers collated data from 69 studies on 31 species, finding fish that were exercised saw a 10 per cent increase in growth.
Report co-author Daniel Gomez Isaza said exercising fish by creating a water flow was a simple and cost-effective strategy.
“A lot of fish, when placed against the flow, they have this response that they immediately swim against a water flow,” he said.
“They’re sort of like bodybuilding fish that can put on weight so fast.”
Dr Gomez Isaza said fish experienced the most benefits if they were swum all day at a speed of two body lengths per second.
“It’s equivalent to, for example, us going for a mild jog,” he said.
“It might seem cruel to exercise fish, but it is actually a form of enrichment for the fish as well.
“Not only are they growing faster, they’re in better condition.
“They can also, for example, tolerate disease more efficiently.”
Dr Gomez Isaza said the effect was “quite consistent” across different species, and didn’t require producers to spend more on food for the fish.
“You go for a run, you get tired and you need to eat more. This is somewhat the case for fish as well,” he said.
“They do eat more food, but … they’re equally efficient at converting this food into mass gain.
“So at the end, you’re not actually feeding the fish any more than you would if they were in still waters.”
Scaling up for industry
The next step is to work with the aquaculture industry to test the exercise regime on a larger scale.
“In aquaculture, of course, you can have big tanks, you can have raceways, or you can have pond aquaculture, so it probably might depend on what type of fish farming is done,” Dr Gomez Isaza said.
“If we think about a tank, you can easily put water flow to generate a water speed.
“So we’re looking to reach out to different aquaculture industries to see how we can upscale this to test it on bigger fish.
“It’s just quite a simple and neat solution to this massive, massive problem.”
