Sargassum ‘nuisance’ could be possible climate change solution (+video)
The floating sargassum farm at Mt Wynne
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April 28, 2023

Sargassum ‘nuisance’ could be possible climate change solution (+video)

by Christina Smith

It is thick, slimy, smelly and ruins every beach it lands on. What is it? If you guessed sargassum seaweed then you are on the money.

It has been just over a decade since excessive sargassum seaweed deposits have caught the attention of the Caribbean.

Within the last few years the massive influx of algae has proven to be a headache for hoteliers who hope to market the island’s beaches to visitors and a nuisance for governments who have to come up with ways to discard the unsightly and smelly mess.


Franziska Elmer, Scientific Project Manager at Seafieldsa

But a solution could be on the horizon, one which will provide a sustainable supply of sargassum to be used in the manufacturing of products and also can be used to remove carbon dioxide in the atmosphere – the ideal solution to climate change.

Further, these scientific breakthroughs are happening right here in St Vincent and the Grenadines spearheaded by Seafields, an aquaculture business based in the United Kingdom.

SEARCHLIGHT paid a visit to the sargassum farm at Mt Wynne to hear from Franziska Elmer, Scientific Project Manager at Seafields, about the progress of the trial to cultivate sargassum.

“The goal of the trial is to find out if we can farm Sargassum … we put some Sargassum in and now we’re taking lots and lots of measurements to see if the Sargassum is happy, growing, how long does it stay alive. It would be good if after six days we have an increase in weight of about 25 to 50 per cent – that shows that the farm is having a good growth rate.”

Seafields big objective is to build large farms that together take up a 94,000 square kilometre barrier located in the South Atlantic Ocean which will house the sargassum where it would grow, and remove carbon dioxide from the atmosphere. The organization has set the target of removing one billion metric tonnes of carbon dioxide from the atmosphere annually when the aquafarm becomes fully operational.

And where will all the removed carbon dioxide go? Seafields intends to sink it to the bottom of the ocean in a process known as carbon sequestration – a fancy term which means removing carbon from the air and storing it somewhere where it won’t easily return to the atmosphere. They intend to sell carbon credits to companies and individuals that have large carbon footprints in order to offset the emissions.

“They buy carbon credits from a company that is actually taking CO2 out of the atmosphere. And we would use the Sargassum; we would take out some nutrients and use those and sell those as fertilisers. And then the rest of it we would sink to the deep sea, where the Sargassum will be locked away for a very long time … the water that will then contain the CO2 takes about 900 years to get back to the surface.”

The growth trial in SVG, which started one year ago, is expected to inform the team about what is needed to make the barrier effective at retaining the sargassum and withstanding the conditions in the ocean. The eight member team, including two locals, have had their fair share of challenges in constructing the barrier during their two previous visits to the island.

“Last May when we were here the first time whenever the wind and the currents didn’t align, our farm would collapse on itself and the inside area would become very, very small,” Elmer explained, also adding that the team’s engineer had to go back to the drawing board to come up with a new design which was able to keep the farm “open” and functioning at it was supposed to.

Today, April 28 is expected to be D-day for the team when they collect data which will indicate if the sargassum is growing as hoped.

“We have 240 [sargassum]pieces with a tag on them that we made last Friday and we’re gonna re-weigh them again tomorrow and see if they got bigger or smaller or the same and if they got bigger than that means the farm works.”

And while the end goal is to make sargassum a global solution for climate change, Seafields is also seeking to grow sargassum to supply companies who need a steady stockpile of the algae in their manufacturing process.

“We need to turn this nuisance into an opportunity and a new blue economy for the Caribbean. One of the problems they have is that you never know how much Sargassum you get each year … it really difficult to make contracts with big companies.

“It also makes it difficult to give stable employment to people. You can help these companies to give them a bit of security that on a day when a lot of Sargassum arrives they can dump some of it into the farm. And then on days when no Sargassum arrives you can take from the farm.”