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01-27-2023

Seaweed farming could boost food security, yet preserve nature

Expanding global seaweed farming could address food security, biodiversity loss and climate change challenges. A new study from the University of Queensland finds that seaweed offers a sustainable alternative to meet the world’s growing need for food and materials.

“Seaweed has great commercial and environmental potential as a nutritious food and a building block for commercial products including animal feed, plastics, fibres, diesel and ethanol,” said study lead author Scott Spillias.

“Our study found that expanding seaweed farming could help reduce demand for terrestrial crops and reduce global agricultural greenhouse gas emissions (GHG) by up to 2.6 billion tons of CO2-equivalent per year.”

The study mapped the potential of farming 34 commercially important seaweed species using the Global Biosphere Management Model. Environmental benefits of a range of scenarios were estimated based on land-use changes, GHG emissions, water and fertilizer use, and projected changes in species presence by 2050.

One scenario that substituted 10 percent of human diets with seaweed products could prevent the development of 110 million hectares of land for farming. 

The researchers also identified the availability of millions of hectares of ocean where farming could be developed. These were mostly found within global exclusive economic zones – EEZ’s. EEZ’s are an area of the sea in which a sovereign state has rights regarding the exploration and use of marine resources.

The largest share of suitable ocean for seaweed farming was found in the Indonesian EEZ, and the Australian EEZ showed the greatest potential and species diversity. 

“The way I like to look at this is to think about ancestral versions of everyday crops – like corn and wheat – which were uninspiring, weedy things,” said Spillias.

“Through thousands of years of breeding we have developed the staple crops that underpin modern societies and seaweed could very well hold similar potential in the future.”

To avoid displacing agriculture problems from land to ocean, Professor Eve McDonald-Madden said farming seawood would have to be carried out with care.

“Our study points out what could be done to address some of the mounting problems of global sustainability facing us, but it can’t be implemented without exercising extreme caution.”

This research is published in the journal Nature Sustainability.

By Katherine Bucko, Earth.com Staff Writer

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