43 countries and islands affected: Caribbean threatened by record quantities of sargassum

Millions of tourists' vacations are being affected by astronomical quantities of sargassum in sun destinations in the Caribbean, Mexico, and Florida. According to an expert, the record for the total mass of arrivals of this foul-smelling algae is on track to be shattered in 2025.

According to Sargassum Monitoring, a non-governmental organization that records sargassum waves on tropical beaches, accumulations of approximately 40 million metric tons have been observed in the high seas between the Americas and Africa.

Figures that made its president and founder, Christine Jimenez-Mariani, widen his eyes, since the previous record in this area was set in 2022 with approximately 24 million metric tons.

"That doesn't mean the amount that will hit land will be greater, but this is the season of record accumulation," she argues. "We're reaching areas that have only very rarely been affected by sargassum. All destinations are grappling with this problem this year. It's practically impossible to escape it."

A "bulwark"

Reports of beaches invaded by this harmful algae, which gives off a rotten egg smell when it decomposes in the sun, have been rife on social media since the beginning of June.

Marc-André Poulin, a Quebecer on vacation in Punta Cana, hasn't been able to get in the water since arriving at the hotel last Sunday. This isn't his first time visiting the Dominican Republic in the summer, and he says he's "never seen anything like it."

"There's a wall one meter high by one and a half meters deep along the entire length of the beach," he laments. "It happens all the time. It's impossible to go into the sea and the smell is terrible. The whole resort spends its time at the pool."

43 countries

Christine Jimenez-Mariani is a French expat who arrived on the Mexican coast in 2013. She has been at the forefront of the massive arrival of the phenomenon, which has only worsened in the last 10 years.

"When I launched Sargassum Monitoring, there were only seven or eight countries affected by sargassum. This year, there are 43," she notes.

A sailor who has sailed the Atlantic several times on her sailboat, in 2018 she decided to take an interest in these mysterious plants which, with each detachment, turn the turquoise and crystal-clear water of the Riviera Maya a murky brown.

"There was no resource available to find out about sargassum arrivals. I contacted several universities that are conducting research on the subject, and we've since been working together to study, map, and catalog it."

Unpredictable

While researchers can confirm that global warming is contributing to the proliferation of sargassum, it remains impossible to accurately predict its movements, as is the case with a tropical storm or a hurricane, for example.

"We have satellite images, but with the changing winds, currents, and conditions, it creates enormous variations. We don't know when a detachment might occur or what direction it will take," concludes Christine Jimenez-Mariani, inviting travelers to document the movements of the Gulf's seaweed and send them to Sargassum Monitoring.