When large swathes of invasive seaweed started washing up on Caribbean beaches in 2011, local residents were perplexed.
Soon, mounds of unsightly sargassum – carried by currents from the Sargasso Sea and linked to climate change – were carpeting the region’s prized coastlines, repelling holidaymakers with the pungent stench emitted as it rots.
Precisely how to tackle it was a dilemma of unprecedented proportions for the tiny tourism-reliant islands with limited resources.In 2018, Barbados’ Prime Minister Mia Mottley declared sargassum a national emergency.
Now, a pioneering group of Caribbean scientists and environmentalists hope to turn the tide on the problem by transforming the troublesome algae into a lucrative biofuel.
They recently launched one of the world’s first vehicles powered by bio-compressed natural gas. The innovative fuel source created at the University of the West Indies (UWI) in Barbados also uses wastewater from local rum distilleries, and dung from the island’s indigenous blackbelly sheep which provides the vital anaerobic bacteria.
The team says any car can be converted to run on the gas via a simple and affordable four-hour installation process, using an easily available kit, at a total cost of around $2,500 (£1,940).
Researchers had initially looked into using sugarcane to reduce reliance on costly, imported fossil fuels and help steer the Caribbean towards its ultimate target of zero emissions.
However, despite Barbados being one of few islands still producing sugarcane, the quantity was deemed insufficient for the team’s ambitious goals, explains the project’s founder Dr Legena Henry.
Sargassum on the other hand, she grimaces, is something “we will never run out of”.
“Tourism has suffered a lot from the seaweed; hotels have been spending millions on tackling it. It’s caused a crisis,” Dr Henry, a renewable energy expert and UWI lecturer, continues.
The idea that it could have a valuable purpose was suggested by one of her students, Brittney McKenzie, who had observed the volume of trucks being deployed to transport sargassum from Barbados’ beaches.
“We’d just spent three weeks researching sugarcane. But I looked at Brittney’s face and she was so excited, I couldn’t break her heart,” Dr Henry recalls.
“We already had rum distillery waste water so we decided to put that with sargassum and see what happened.”
Brittney was tasked with collecting seaweed from beaches and setting up small scale bioreactors to conduct preliminary research.
“Within just two weeks we got pretty good results,” Brittney said. “It was turning into something even bigger than we initially thought.”
The team filed a patent on their formula and, in 2019, presented their project to potential investors during a side meeting at the UN General Assembly in New York.
Upon touchdown back in Barbados, Dr Henry’s phone was “buzzing” with messages of congratulation – including one from US non-profit Blue Chip Foundation offering $100,000 to get the work off the ground.
Biologist Shamika Spencer was hired to experiment with differing amounts of sargassum and waste water to figure out which combination produced the most biogas.