A study published in Nature Ecology & Evolution reveals that the planet's seas and oceans can host about 13 million km2 of aquaculture and thus reduce at least part of the planet's food insecurity.

As the world's population grows - according to UN figures it will reach 9.8 billion by 2050, and 11.2 billion by 2100 - our food systems are under intense pressure to ensure food production, especially animal protein. But according to a team of US and Chinese researchers, led by Rebecca Gentryde of the University of California at Santa Barbara, the human health benefits of diets rich in fish and the sustainability of marine aquaculture compared to land-based meat production make it urgent to consider the potential of this solution.

For these scientists, quoted by green savers, the oceans may represent an immense opportunity for food production in a sustainable way, even though the open ocean environment is largely untapped as an agricultural resource.

In their research, the researchers excluded ocean areas unsuitable for aquaculture because of certain environmental or human use restrictions. This is the case of areas with inadequate growing conditions due to low oxygen (fish only) and low phytocycloteric food availability (bivalves only). They have also eliminated very deep waters, or waters already allocated for other activities such as oil extraction, heavy shipping or marine life protection areas.

From observing 120 species of fish and 60 species of crustaceans, they defined growth rates, optimal temperatures, the concentration of oxygen that is needed, or phytoplankton density to deduce the maximum concentration of marine animals that can harbor coastal waters. In the end, they concluded that "almost all coastal countries have great potential for marine aquaculture."

The research team thus argues that about 11,400,000 km2 of ocean could be devoted to fish farming and 1,500,000 km2 could be developed for bivalves, demonstrating that there is expansive potential worldwide, including tropical and temperate countries. Total production would be considerable: if all the areas designated as suitable in this study were developed (assuming no economic, environmental or social constraints), Rebecca Gentryde and her colleagues estimate that about 15 billion tons of fish could be farmed each year - more than 100 times current consumption.

Still, even while highlighting the full potential of aquaculture (which already provides about 50% of the world's consumed fish), scientists warn of the need to "carefully consider the impact of aquatic food production on aquatic and terrestrial ecosystems and resources."