Kona-grown seaweed helping reduce cattle methane emissions

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Algae Technician Kelsi Clarke monitors Asparagopsis taxiformis seaweed at Blue Ocean Barns’ growing facility in NELHA. Courtesy photo/Special to West Hawaii Today)
A cow grazes in North Kona. (Laura Ruminski/West Hawaii Today file photo)
Puffballs of Asparagopsis taxiformis, known as tetrasporophytes, float freely in a Blue Ocean Barns growing vessel. Courtesy photo/Special to West Hawaii Today
After the seaweed is harvested, Blue Ocean Barns dries it and mills it into a powder for easy mixing into cows' regular rations. Courtesy photo/Special to West Hawaii Today
Growing vessels filled with Asparagopsis taxiformis seaweed at Blue Ocean Barns facility. Courtesy photo/Special to West Hawaii Today
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An agricultural technology company located at the Natural Energy Laboratory of Hawaii Authority is growing seaweed in an effort to reduce cattle methane emissions around the world.

The all-natural seaweed Asparagopsis taxiformis, locally known as limu kohu, has been shown in published research and on-farm trials to safely eliminate more than 80% of cows’ methane production without changing the taste of milk or meat.

The seaweed supplement is added to cattle feed in tiny daily amounts, and the natural remedy then stops the formation of methane in the cow’s rumen, or first stomach, nearly eliminating the emission of the potent greenhouse gas associated with climate change. A year of cow burps is equivalent to the greenhouse gases emitted by a gasoline-engine passenger car.

Blue Ocean Barns started at NELHA in March 2020 on a half-acre parcel. CEO Joan Salwen said the company that produces Brominata got started in California when she and her co-founder were at Stanford University.

“We discovered a particular seaweed had strong potential based on limited research in Australia to reduce the greenhouse gas emissions from cattle,” she said. “While at Stanford, we worked collaboratively with other universities such as UC Davis, which is livestock focused to test whether a seaweed that had been found to reduce methane gas in one lab could be replicated.”

The duo raised money from family foundations and the federal government to prove that the seaweed could serve as a digestive aid for cattle, shutting down the process of methane burps.

“We had done two years of research that was published in journals. It really became clear that this particular seaweed was good for this purpose and needed to be grown at scale,” said Salwen. “That’s when we started to look to Hawaii because California doesn’t have anything like NELHA, a ready-made infrastructure that is perfectly tailored to people using ocean water for business, academic or research purposes.”

By growing the limu kohu seaweed at NELHA, Blue Ocean Barns is complementing the natural ecosystem rather than introducing a species that doesn’t belong in Hawaii.

The company is initially focusing on dairy cows, providing the milkers with the seaweed supplement to their feed.

“We are using the dairy industry to help us learn how best to serve ranchers and feed lot operators,” said Salwen.

Currently, Blue Ocean Barns is growing and harvesting the limu to feed 1,000 cows with over a dozen employees in Kona. The company plans to expand the operation to 14 acres at NELHA with projections to feed one million cows by 2026, and then 100 million cows by the end of the decade.

Among the companies that have become Blue Ocean Barns partners are Ben &Jerry’s, Clover Sonoma, and Straus Family Creamery.

“We are growing it for a very unique and special purpose, one that is going to place Hawaii in a position of leadership with climate change and averting the impact of our food system on our planet. Hawaii will stand to be very proud of what this land and the people that are working here are doing on behalf of the entire planet,” she said.