Kajima Mass Produces Algae for Cleaner Cow Burps; 30% of Japan’s Methane Emissions from Livestock

The Yomiuri Shimbun
Cutting methane emissions with red sea plume

Major contractor Kajima Corp. has developed a technology to mass produce seaweed that can cut methane in cow burps. Methane emissions are a global issue, as the gas’ greenhouse effect is some 25 times stronger than that of carbon dioxide.

Asparagopsis taxiformis, also known as red sea plume, is said to suppress methane emissions from cows when mixed into their feed. Kajima will continue to research the technology in collaboration with dairy farmers and others, as it aims to commercialize the algae as a cattle feed.

Ruminants such as cows and sheep produce methane when they digest food in their stomachs. The methane is then released into the atmosphere in burps.

According to the National Institute for Environmental Studies, Japan emitted methane equivalent to 27.4 million tons of CO2 in fiscal 2021. Of this, about 30% came from livestock such as cows.

Red sea plume is a type of fern-shaped red algae that lives in the Pacific Ocean, including around Japan. Research abroad has shown that mixing the algae into cattle feed can cut methane from cows, reducing emissions of the gas by more than 90%.

Kajima collected the algae, which grow to a height of 10 to 30 centimeters, and cut them into 1- to 2-millimeter-long pieces to cultivate them in a tank on land. By adjusting water temperature, salinity and light received, the company was able to increase the mass of the algae by 300% in two weeks. According to Kajima, its technology is the first in Japan that allows for mass production of the species on land.

Kajima began experimenting with growing the algae in a small 2-liter tank in April last year, and is now able to mass produce them in a 1,000-liter outdoor tank. The company said it will continue its research and may license the tech to other companies for widespread mass production.

Kajima established the Hayama Marine Science Laboratory in Hayama, Kanagawa Prefecture, in 1984, and has been researching marine conservation.