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Obscure pink seaweed may help reduce global carbon emissions

By Jessie Higgins
When fed to cows, this pink seaweed can reduce or eliminate the methane the animal produces. Photo courtesy of the University of the Sunshine Coast
When fed to cows, this pink seaweed can reduce or eliminate the methane the animal produces. Photo courtesy of the University of the Sunshine Coast

Aug. 16 (UPI) -- Marine scientists around the world are seeking a way to mass produce an obscure tropical pink seaweed that can stop cows from burping so much methane gas.

Their hope is to dramatically reduce global greenhouse gas emissions by producing enough asparagopsis seaweed to feed the world's 1.5 billion cows, which along with other ruminant animals are responsible for 14.5 percent of the world's annual greenhouse gas emissions, according to the United Nations.

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The problem is that nobody knows exactly how this seaweed grows.

"We don't understand how it reproduces," said Julie Qiu, a spokeswoman for Australis Aquaculture, a Massachusetts company that hopes to grow the seaweed commercially. "This has never been done before."

Until it is, there is no way the seaweed will have a noticeable impact on methane emissions. There is simply not enough of it growing in the wild to feed domesticated ruminant animals. Currently, it can be obtained only by scavenging for it in tropical areas, like off the coast of Australia. That supply is limited.

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Australis' researchers at the company's seafood farming facility in Vietnam are among a handful of specialized marine scientists racing to understand the red algae seaweed. The team hopes to farm it in ocean pens.

Elsewhere, marine biologists at the University of California San Diego are trying to grow the seaweed in indoor pools. And researchers at the University of the Sunshine Coast in Australia announced last week they were starting a project to try to grow it off the Australian coast.

"The Sunshine Coast is actually an epicenter of biodiversity for ... asparagopsis," Nick Paul, an associate professor at the University of the Sunshine Coast and the lead of its seaweed research group, said in a university video. "You would actually see it if you go snorkeling or are at the beach."

The push to grow asparagopsis began in earnest a couple of years ago after agricultural researchers in Australia first discovered that the seaweed miraculously eliminated methane production in cows -- at least in a lab.

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Cows, like all ruminant animals, belch methane gas as a byproduct of their digestion. It's one of the reasons the United Nations found the livestock industry to be one of the planet's top contributors of greenhouse gases.

Subsequent studies around the world found that cows that ate the seaweed did burp substantially less methane.

The findings aroused immediate attention.

"This seaweed has caused a lot of global interest," Paul said. "But the one missing step, the big thing that is going to make sure this works at a global scale, is to make sure we can produce the seaweed sustainably."

But progress is slow. Without knowing what environmental event triggers the plant to reproduce, it cannot yet be reliably grown in an ocean farm, Qiu said.

So far, researchers have only succeeded in growing the seaweed in indoor pools. They're able to do this because branches cut off existing plants will grow into their own plants. This presents obvious production limitations.

And there are other issues.

"It has a finicky life cycle," said Jennifer Smith, a marine ecologist at the Scripps Institution of Oceanography at the University of California San Diego, who is leading the university's effort to grow asparagopsis. "And it's also pretty delicate and fragile. It's not something you can just throw out in the ocean."

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Despite the obstacles, the researchers are optimistic that a breakthrough will come. And when it does, the impact it will have on carbon emissions could be substantial.

"If we're able to work out how to scale up the seaweed to become 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," Paul said. "And it's ultimately going to save us all billions of dollars."

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