A ‘sea tractor’ harvests and replants carbon-capturing seaweed at this

In a collection of floating seaweed farms off the coast of Bali, Indonesia, a catamaran travels again and forth by way of traces of dangling pink algae. Customized know-how on board routinely harvests and replants the seaweed, which rapidly grows a number of ft lengthy. The system is designed to assist the tiny seaweed business scale up—and to seize a few of seaweed’s potential to assist battle local weather change.

“Agriculture on the ocean is in its infancy,” says Shrikumar Suryanarayan, cofounder and managing director of Sea6 Energy, the India-based firm that designed the “Seacombine,” the tractor-like machine now in use at its Indonesian seaweed farm. The corporate simply introduced a brand new $9 million funding spherical, led by Aqua-Spark, an funding agency centered on sustainable aquaculture. There’s rising curiosity in seaweed farming now partly due to seaweed’s potential to soak up carbon: Macroalgae like seaweed can develop as rapidly as two ft a day, sucking up CO2 a lot quicker than timber (and not like forests, seaweed doesn’t face dangers from drought or hearth). Whereas some tasks intention to completely sequester that carbon by sinking seaweed to the ocean flooring, the algae will also be used to make merchandise, from fish feed to human meals. Grown at a big scale, seaweed might exchange among the crude oil used to make jet gas or plastic. However it’s been so costly to develop that it may’t compete with fossil fuels.

[Photo: Courtesy of Sea6 Energy]

Proper now, some seaweed is cultivated to be used in components like carrageenan, an ingredient used as a stabilizer in ice cream, toothpaste, and different merchandise. However the technique of farming is labor-intensive. “It’s very handbook, with a variety of labor concerned, and the areas during which [seaweed] could be grown are restricted to shallow and calm waters the place folks can stroll out,” says Suryanarayan. Although strategies differ relying on the kind of seaweed (and some seaweed is gathered from the wild), farmers usually have to connect items of seaweed to rope traces or nets by hand, await them to develop, and then manually harvest and “re-seed” the traces.

Seaweed farming avoids among the prices of land-based agriculture—growers don’t have to pay for irrigation or use fertilizer or different soil amendments. The principle value is labor. And whereas the handbook course of supplies extra jobs, it signifies that the business can’t simply develop. There’s additionally solely a restricted space, very near coastlines, the place it’s attainable to function.


Roughly a decade in the past, whereas instructing at a college in India, Suryanarayan started occupied with seaweed as he thought of the potential of biofuels. India is likely one of the world’s largest customers of crude oil, nearly all of which is imported. Biofuels comprised of vegetation may very well be a alternative, however to utterly exchange oil, the vegetation must be grown on an enormous scale—round a billion tons of biomass a yr. “A billion tons of biomass is your complete agricultural output of India,” he says. There was no possible method to produce it with out disrupting the meals provide. Seaweed, grown within the ocean, wouldn’t have the identical drawback. It simply wanted to be cheaper to provide.

“We rapidly realized that there have been two issues that we have to meet if this was ever going to be viable,” he says. “One is that it needed to be grown at scale. And it needed to be extraordinarily low cost and value efficient.”

[Photo: Courtesy of Sea6 Energy]

The corporate continues to be engaged on decreasing the price of its system, and hasn’t began making an attempt to fabricate biofuel. However it’s already promoting one other seaweed-based product known as a biostimulant that farmers can add to soil to assist vegetation develop quicker; in checks on cornfields in Iowa, farmers noticed yields develop by 10%. For farmers, it’s a method to earn extra. However the product additionally has a local weather profit, because the vegetation take up extra CO2 with none additional enter. One other seaweed-based product could be added to animal feed to enhance well being, so farmers can use fewer antibiotics. (A completely different kind of seaweed, not at present grown by Sea6, could be added to cattle feed to cut back methane in cow burps, one other driver of local weather change.)

Inside three or 4 years, the corporate goals to broaden and decrease the price of manufacturing sufficient that it’s possible to make bioplastics from seaweed. Ultimately, Suryanarayan says additionally they hopes to have the ability to produce biofuel that may very well be utilized in airplanes or cargo ships, each of which might’t simply run on electrical energy. Biofuels might doubtlessly be produced from seaweed grown regionally in Pacific island nations, so cargo ships crossing the Pacific might cease to refuel. And India might doubtlessly wean itself off crude oil. “I believe this is certainly nearby,” says Suryanarayan. “We’ve the know-how, we’ve the flexibility. We want the capital.”

The brand new spherical of funding is a begin. Seaweed “is a possible unbelievable resolution,” says Amy Novogratz, founder and managing accomplice at Aqua-Spark. “We simply have to put extra assets behind it and study extra about producing that the quantities we’d like in a means that works.”