Aquaculture is shifting toward less sustainable species: New study

While aquaculture has grown rapidly to meet global seafood demand, it is increasingly relying on species that are less beneficial for food security, climate mitigation, and biodiversity, according to a new study from researchers at the University of British Columbia.

The study, published in Fish and Fisheries, analyzed global aquaculture production from 1950 to 2023 and found that, since the 1980s, the industry has shifted toward a smaller number of intensively farmed species—particularly finfish—that tend to have lower overall sustainability potential.

“Aquaculture has enormous potential to support global food systems and environmental goals, but our findings show that current production trends are moving us in the wrong direction,” said Dr. William Cheung, professor with the Institute for the Oceans and Fisheries (IOF) at UBC, and senior author of the study.  

“We’re seeing a growing mismatch between what we produce and what would best support climate, biodiversity and food security outcomes.”

The research evaluated how different species contribute to three key areas: food provision, climate impact, and biodiversity. It found that earlier aquaculture systems—dominated by species such as seaweed and shellfish—had higher sustainability potential compared to modern systems focused on fed species like salmon and shrimp.

The study developed indices that measured how aquaculture production contributes to food, climate, and biodiversity goals, aligned with UN Sustainable goals. China, for example, accounted for 56 per cent of global aquaculture production in 2022, yet its production mix showed declines across all three indices between the 1976–1980 baseline and 2019–2023: −14.1 per cent for food, −21.6 per cent for climate, and −12.9 per cent for biodiversity. In the Americas, the food index increased only marginally (+0.8 per cent), while the climate and biodiversity indices declined by 11.4 per cent and 9.1 per cent, respectively.

“Salmon aquaculture is the fastest-growing food sector in the world, however it’s strongly affected by warming waters and deoxygenation, and is a species that has lower food, climate and biodiversity potential,” said Aleah Wong, lead author and PhD candidate in the IOF.

“Not all aquaculture species are equal. Some, like bivalves and seaweed, can deliver significant environmental benefits, while others come with higher trade-offs. Currently, many of the most beneficial species are under-represented in global production.”

The researchers point to expanding the production of low-impact species—such as bivalves and seaweed—as a key pathway forward. However, they note that market demand, policy frameworks, and consumer preferences will play a critical role in enabling this transition.

“Food security is shaped by factors like production efficiency and species’ nutrient density, but also by complex dynamics between producers, consumers, markets and regulatory bodies that affect food security indirectly,” said Dr. Cheung. “Many regions already farm species with high sustainability potential. By scaling up these species and diversifying production, aquaculture can better contribute to global sustainability targets.”

The study underscored that the future of aquaculture depends not only on how much is produced, but on what is produced—and how those choices align with global environmental and food system goals.

“Shifting toward more sustainable aquaculture would require coordinated international action,” said Wong. “Better policies, investment in innovation, and changes in what consumers are willing to eat need to be made.”