It is barely visible and requires no irrigation or fertilizer: Lying off the coast of Australia is a huge seaweed crop destined to curb the climate-changing flatulence and bel of livestock.
The underwater farm extends across 1,800 hectares (4,400 acres) of the Tasman Sea, about 10 minutes from the small port town of Tribnina in the Tasmanian state.
Below the waves is the forest of asparagus, and red seaweeds are rich in coastal waters of Tasmania are rich in organic complex bromine plants.
Fran Cowley, a researcher at the University of New England in Australia, said more than 40 studies have shown that adding seaweed to feed or cereals can reduce methane emissions from livestock.
According to the United Nations Food and Agriculture Organization, emissions from ruminants and fertilizer management practices account for more than 32% of the world methane emissions associated with human activities.
“When we look at the gold standard measurement of methane inhibition, asparagus is able to inhibit methane inhibition almost completely — and therefore, 95% of the inhibition,” said Cowley, a livestock production professor and lead researcher for ruminants.
Although the atmosphere is much less abundant than carbon dioxide, methane is about 80 times more effective over a 20-year time frame.
But its short life span makes it an important lever to limit global warming.
– Juicy meat –
Cowley led one of the longest experiments into asparagus, which took cattle feed batches in eastern Queensland for more than 200 days.
Results published in August 2024 show that animals have reduced emissions by half compared to those not receiving supplements.
The results show that previous research has improved, one of the most advanced studies in the field at the time, with emissions from Japanese cattle herds reduced by 28%.
Cowley said bromobifruit in seaweed can affect the digestive system and curb the animal's burps and farts without affecting its health or the quality of the food it produces.
Bromooform is a worrying issue, she said, because at a high level it is considered to be carcinogenic to rats and possibly humans.
But researchers found it degrades in the stomachs of grazing animals.
“So there is no accumulation of bromination in meat or milk because it just starts at a relatively low dose,” Cowley told AFP.
“All studies done on meat have absolutely no accumulation of bromination, effects on taste, tenderness or juicy meat.”
She said studies show that any damage to the rumen of animals — a chamber in the stomach that destroys the plants — is no more damaged than those feeding cereal-based feedlot diets.
– “Enable Force” –
In Triabunna, the marine farm in Sea Forest produces feed from seaweed: oil, pellets and “licking blocks”, a solid form that animals can lick off.
After about 15 years in the textile industry, Sam Elsom, founder and CEO of Sea Forest, turned to seaweed cultivation in 2019.
He told AFP that the company wanted to be a “promoting force” to make agricultural products sustainable without paying extra for farmers and consumers.
Seaweed is partly grown in the high seas and partly in filtered seawater ponds on land, making it easier to replicate in the rest of the world and allows growers to control the availability of light, nutrients and carbon.
Elsom said Heisen Forest has partnered with Tasmanian dairy company Ashgrove and Australian burger barbecue chain, and signed a deal with British supermarket chain Morrison last year.
He said it also held “encouragement” talks with some French dairy producers and is registering its seaweed products with the European Food Safety Agency.
Elsom said the biggest challenge is the cost to farmers, who need economic incentives and support to reduce efforts worthwhile to reduce livestock methane emissions.
He said the ocean provides “amazing natural resources” for food security.
“71% of the Earth’s surface is surrounded by the ocean, and seaweed requires zero input: no irrigation, no fertilizer, no pesticides.
“So it can be 30 times faster than land-based plants. It's very exciting.”
GP/DJW/Stu
