Grenada is exploring uses for sargassum to turn a smelly seaweed problem into clean energy and economic growth.
If you’ve ever taken a beach vacation and caught a whiff of something rotten in the air, chances are you’ve encountered sargassum. In places like Grenada, thick mats of this seaweed accumulate along the coast, emitting a strong, unpleasant odour as it decays. It’s more than just a bad smell—it damages boats, harms tourism, and may even impact people’s health.
But now, the same seaweed that’s plagued Caribbean coastlines is being looked at in a new way. From biogas to bioplastics, researchers, companies, and government leaders are finding new uses for sargassum that could boost local economies, reduce pollution, and even help fight climate change.
Sargassum is a brown seaweed that floats freely in the ocean. Usually, it’s harmless. But in recent years, huge blooms have overwhelmed Caribbean shorelines, creating thick blankets that rot in the sun. In places like Soubise, a fishing village in Grenada, the smell is so strong it clings to passing cars and lingers in homes.
The weed clogs boat propellers, making it harder for fishers to work. It also releases gases like methane and hydrogen sulfide when it decays, which can corrode metal, damage electronics, and trigger skin rashes.
Coastal erosion is worsening, too. As heavy machinery removes sargassum, it also scrapes away valuable sand and marine life. Manual removal is slow and labour-intensive, but necessary to preserve beaches—Grenada’s key tourism asset.
Scientists believe the sargassum surge began around 2009. Changing wind patterns and ocean currents are thought to have pulled nutrient-rich waters to the surface, fueling giant seaweed blooms. While there is still debate over the exact causes, warming oceans and nutrient pollution from fertilizers may be making the problem worse.
Instead of just battling the seaweed, Grenada is now exploring ways to benefit from it. The government is partnering with the European Union and private companies to create a new market focused on uses for sargassum.
UK-based aquaculture firm Seafields has created ocean farms to intercept sargassum before it reaches land. This prevents it from rotting on shore and releasing methane, a powerful greenhouse gas.
But Seafields doesn’t just remove the seaweed—it finds uses for sargassum. The company claims sargassum can be turned into bioplastics, crop fertilizers, and even fuel. Compared to other seaweeds, it’s cheaper and easier to farm, making it a promising source for eco-friendly materials.
One use is as a biostimulant—a type of natural fertilizer. According to Seafields, applying processed sargassum to crops can boost yields by 10 to 14 percent. With increasing pressure to grow food sustainably, this could open up a $200 billion global export market. The Caribbean, where sargassum is plentiful, is in a strong position to lead.
Grenadian startup SarGas is also making waves. The company uses biodigesters—large machines that break down organic matter—to convert sargassum into clean energy. The resulting biogas powers ovens at True Blue Bay Resort’s House of Chocolate bakery in St. George’s.
Along with biogas, the process creates digestate—a nutrient-rich substance that works as an organic fertilizer. These dual benefits have caught the attention of government officials. SarGas has recently received approval to construct a larger biogas facility, which will generate electricity for the island, where power is typically produced using expensive diesel.
Grenada’s Prime Minister, Dickon Mitchell, views this as more than just waste management. At a recent conference, he emphasized the island’s “unique opportunity” to turn a harmful nuisance into something beneficial for everyone—from fishers to hoteliers.
Mitchell’s government has set a goal to collect 10,000 tons of sargassum by 2026 and is actively seeking proposals from companies interested in working on sargassum-based projects.
The momentum is growing. Some fishermen have noticed that the weed attracts valuable fish, such as mahi-mahi. Farmers are collecting sargassum to fertilize their crops. Hotels are eager to find sustainable ways to manage beach cleanups while protecting their image and preserving marine ecosystems.
Beach removal is slow and delicate. Heavy machines damage sand and marine life, so many resorts rely on manual labour. Still, maintaining clean beaches is essential—tourism is a key part of the economy, and sargassum poses a threat to that.
Kirl Grant-Hoschtialek of the Grenada Tourism Authority explains that maintaining world-class beaches is a priority. Workers remove sargassum by hand to minimize environmental damage.
Despite the optimism, the problem is unlikely to go away soon. The smell, the damage to boats and appliances, and the coastal erosion all continue to affect daily life, especially in places like Soubise.
Locals say the stench follows you, even after you leave the beach. “Some people say you get accustomed to the smell,” one resident said. “But you can never get accustomed to it.”
Still, with governments, private companies, and communities all pulling in the same direction, new uses for sargassum could help turn the tide.
