Algae is much more than just a slimy plant that makes you feel gross. It really can do anything. It’s one of the most abundant plants on the planet, a staple food for millions of people around the world, soaks up carbon, could be used as a substitute for plastics, and is even greener cow feed (more seaweed means less methane in cow farts). , after some research).
More algae cultivation is also a potentially important part of the solution to global food insecurity. A study published in the journal Jan. 26 nature sustainability sheds new light on how much.
[Related: Why seaweed is a natural fit for replacing certain plastics.]
“Our study found that expanding the cultivation of algae could help reduce demand for land crops and reduce global agricultural greenhouse gas (GHG) emissions by up to 2.6 billion tonnes of CO2-equivalent per year,” says Scott Spillias , a PhD student at the University of Queensland in Australia (UQ) and a co-author of the study, said in a statement. “Algae have great commercial and environmental potential as a nutritious food and as a building block for commercial products such as animal feed, plastics, fiber, diesel and ethanol.”
The team used the Global Biosphere Management Model, which assesses land-use competition between agriculture, bioenergy and forestry, to show the potential for growing more of the 34 commercially important seaweed species. In addition, the potential environmental benefits were estimated using a range of scenarios based on water and fertilizer use, greenhouse gas emissions, land use change and projected changes in species abundance through 2050.
“In a scenario where we replace 10 percent of the world’s human diet with algae products, 110 million hectares of land could be prevented from being developed for agriculture,” Spillias said. “We have also identified millions of available hectares of ocean within global exclusive economic zones (EEZs) where agriculture could be developed.”
EEZs are marine areas where a sovereign state has special rights in relation to the exploration and exploitation of the marine resources in the area. With up to 114 million hectares suitable for algae farming, the largest suitable ocean was the Indonesian EEZ, according to the study. Australia’s EEZ also holds potential, harboring at least 22 commercially viable species of algae and approximately 75 million hectares of suitable ocean.
According to Spillias, many of the native species of algae that live in Australian waters have not been studied from a commercial production perspective.
“I like to think of this as thinking of old versions of everyday crops like corn and wheat, which were uninspiring, weedy things,” Spillias said. “Through thousands of years of breeding, we have developed the staple foods that sustain modern societies, and algae may very well have similar potential in the future.”
[Related: Putting cows on a seaweed diet helps curb their methane burps.]
Key issues with expanding seaweed farming include the ropes and other equipment used in aquaculture, which may result in entanglement of some marine mammals, the risk of certain species becoming invasive, and ensuring that sufficient sunlight continues to penetrate below the surface.
The team cautions that expanding algae production would need to be done with care to avoid some of the problems spilling from land to the ocean.
“Our study highlights what could be done to address some of the growing global sustainability issues we face,” said co-author Eve McDonald-Madden, research fellow at QU’s School of Earth and Environmental Sciences. in a statement. “But it cannot be done without extreme caution.”