Seaweed promises climate change solution

Tracey Ferrier
Queensland researchers say a seaweed could stop cows burping methane into the atmosphere

Queensland researchers say a pink seaweed that stops cows from burping could help slash Australia's greenhouse gas emissions.

Asparagopsis grows prolifically off the Queensland coast and a CSIRO study five years ago found it was the only seaweed that stops cows burping methane into the atmosphere.

Researchers from the University of the Sunshine Coast are now investigating how it might be farmed on a commercial scale and added to cattle feed to slash emissions.

Associate Professor Nick Paul says Australia's emissions could be cut by 10 per cent if every cow in Australia was fed the seaweed.

"Seaweed is something that cows are known to eat. They will actually wander down to the beach and have a bit of a nibble," says Dr Paul, from the university's Seaweed Research Group.

"When added to cow feed, at less than two per cent of the dry matter, this particular seaweed completely knocks out methane production."

The seaweed contains chemicals that reduce the microbes in the cows' stomachs that cause them to burp when they eat grass.

Dr Paul says global interest in the seaweed is high and the goal now is to work out how to sustainably farm enough to supplement cattle feed on a national, or even global scale.

As well, scientist Ana Wegner says efforts are focused on how to produce seaweed with greater concentrations of the chemical that stops cows from producing so much gas.

Efforts are also focused on how to move crops from the lab, to large outdoor aquaculture tanks.

Dr Paul says agriculture accounts for six per cent of global greenhouse gas emissions, and methane is a far more potent greenhouse gas than carbon dioxide.

"(It) has 28 times the heating potential of CO2 - and most of that agricultural production of methane is coming from livestock that are ruminants," he says.

"If we're able to work out how to scale up the seaweed to a level that can feed all of the cows and the sheep and the goats around the world then it's going to have a huge impact on the climate."