EXPANDING global seaweed farming could go a long way to addressing the planet's food security, biodiversity loss and climate change challenges.
A University of Queensland-led study published in the journal Nature Sustainability has shown that seaweed offered a sustainable alternative to land-based agricultural expansion to meet the world's growing need for food and materials.
PhD candidate Scott Spillias, from UQ's School of Earth and Environmental Science, said seaweed had great commercial and environmental potential as a nutritious food and a building block for commercial products.
Uses included animal feed, plastics, fibres, diesel and ethanol.
"Our study found that expanding seaweed farming could help reduce demand for terrestrial crops and reduce global agricultural greenhouse gas emissions by up to 2.6 billion tonnes of CO2-equivalent per year," Mr Spillias said.
In one scenario where we substituted 10 per cent of human diets globally with seaweed products, the development of 110 million hectares of land for farming could be prevented.
- Scott Spillias, University of Queensland
Researchers identified 34 commercially important seaweed species with the potential to be farmed.
However, many of the native species in Australian waters had not yet been studied from a commercial production perspective.
Using the Global Biosphere Management Model, they estimated the environmental benefits of a range of scenarios based on land-use changes, GHG emissions, water and fertiliser use, and projected changes in species presence by 2050.
"In one scenario where we substituted 10 per cent of human diets globally with seaweed products, the development of 110 million hectares of land for farming could be prevented," Mr Spillias said.
"We also identified millions of available hectares of ocean within global exclusive economic zones, where farming could be developed."
The study shows the largest share of suitable ocean is in the Indonesian EEZ, where up to 114 million hectares is estimated to be approriate for seaweed farming.
"The Australian EEZ also shows great potential and species diversity, with at least 22 commercially viable species and an estimated 75 million hectares of ocean being suitable," he said
The study also involved researchers from the International Institute for Applied Systems Analysis, CSIRO and the University of Tasmania.
