Queensland scientists are getting serious about seaweed to address the planet's food security and environmental and climate change challenges.
University of Queensland School of Earth and Environmental Science PhD candidate Scott Spillias's study found expanding seaweed farming could help reduce demand for terrestrial crops.
He said his team's study also found farming could reduce global agricultural greenhouse gas emissions by up to 2.6 billion tonnes of CO2-equivalent per year.
How seaweed helps
Mr Spillias said seaweed's uses were not just limited to reducing greenhouse gas emissions.
"In the way we can process corn or soy, we can process seaweed to extract specific nutrients or proteins so that we can feed it to animals," he said.
"We can also use it to produce biofuels like ethanol or biodiesel."
Indonesia has an established seaweed industry, growing species that require warmer waters than Australia.
Department of Agriculture graduate Madeleine Grist said Indonesia produced about 66 per cent of the hydrocolloid seaweeds, which included carrageenan seaweeds.
"Carrageenan is like a gelling agent, so it's used in a lot of pharmaceuticals, and you'll find it in your vegan ice creams because it is a substitute for gelatin in a lot of cases," she said.
Ms Grist travelled to South Sulawesi to experience the more established industry in person.
She said hoped to bring knowledge back to Australia as the seaweed industry grew.
"[Compared with Australia] Indonesia is definitely where it's a more developed industry," she said.
Scaling up production
Seaweed is a low-value crop with a high-value potential, which has scientists excited.
"The analysis we did showed that around 650 million hectares of the ocean would be suitable for seaweed farming and that's around 2 per cent of the global ocean," Mr Spillias said.
"Those places would be suitable in the sense that you could put a seaweed farm there and it wouldn't be too difficult."
Australia is also home to many native species of seaweed, but unlike crops such as wheat has not received much attention from a domestication perspective.
"Terrestrial crops have undergone thousands of years of domestication and people have selected the traits they want and so those are the crops with the big, nutritious fruits that we use today," Mr Spillias said.
"[Domestication] is going to make the seaweed industry a lot more viable, both economically and sustainably."
Barriers to change
Seaweed farming provides diverse sources of income for communities, especially the smallholder farming system in Indonesia.
"While these seaweed farmers [in Indonesia] are earning a lot more money than they would with fishing they don't earn much for the amount per kilo of seaweed based on the amount of labour they have to put into it," Ms Grist said.
"There's not a lot of mechanisation; a lot of it is done by hand."
Mr Spillias said the economics of seaweed farming was a barrier.
"The reality is that the ocean is a pretty hostile environment for humans, for things that humans make, and so there's a lot of risk with building seaweed farms and maintaining them," he said.
"Right now there are these economic barriers, but those are going to start to go away as we develop the technologies to push humanity further out into the ocean."
Helping the environment
In his research, Mr Spillias estimated the environmental benefits of different seaweed production scenarios.
Considering factors such as land-use change, greenhouse gas emissions, water and fertiliser use, and the expected changes in species prevalence by 2050, Mr Spillias could identify potential benefits of expanding seaweed production.
"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.
