Fish farming – or aquaculture – holds vast potential to feed the world, scientists believe.

However, a new study by the University of Miami’s Rosenstiel School found that global fish farming relies on larger amounts of wild-caught ocean fish than previously thought, according to a university press release. These wild-caught fish end up as food for farmed carnivorous species such as salmon, trout and eel.

The study was part of a special issue focused on scaling up the aquaculture industry’s contributions to food systems for sustainability.

“These findings call into question long-held assumptions about the sustainability of the rapidly growing aquaculture industry and provide a range of plausible estimates for its impact on wild fish populations,” the Oct. 17 news release said.

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The research was led by an international team of scientists from Rosenstiel, Oceana in Peru and New York University. It provided a reassessment of the fish-in:fish-out (FI:FO) ratio for global fed aquaculture – a key measure used to assess the efficiency and sustainability of aquaculture.

The findings indicate that the ratio of wild fish intakes to farmed fish production is 27% to 30% higher than previously estimated. For farmed carnivorous species, the wild fish intake probably exceeded twice the farmed fish biomass produced.

“Our study reveals that the aquaculture industry relies more heavily on the extraction of wild fish than previous research has suggested,” said Spencer Roberts, a Rosenstiel PhD student and lead author of the study. “This demonstrates the scale at which aquaculture could impact marine ecosystems.”

The research team’s approach included accounting for overlooked sources of wild fish in aquaculture feed, such as trimmings and by-products from wild-caught fish.

“This research shows that the assumptions we made about carnivore aquaculture were too optimistic and is another reason to think strategically about the types of aquatic species that make the most sense to mass produce,” he said Jennifer Jacquet, co-author of the paper. the study and a Professor Rosenstiel.

The study also examined the environmental trade-offs involved in reducing the use of wild fish in aquaculture feed.

“The offshore aquaculture industry is growing so fast that wild-caught fish are not being replaced in their feed. Instead, other food sources only supplement the use of wild fish,” said Patricia Majluf, senior scientist at Oceana.

Peru is home to the largest fishmeal fishery in the world.

The findings have significant implications for policymakers, investors and consumers, the press release said. The study called for more comprehensive and transparent reporting of feed ingredients in the aquaculture industry.