Sargassum swamps the Riviera Maya and pushes tourism into crisis

The beaches of Cancún and the Riviera Maya are going through a crisis. Sargassum has reached record levels along Mexico's Caribbean coast, covering the water with extensive mats of seaweed.

The algae give off a strong smell both in the water and along the shoreline. Swimming becomes difficult, and decomposition can cause skin irritation, as can the small marine organisms living inside the mats.

Removal requires continuous intervention on several levels. Collection vessels work in open water, floating barriers limit how much seaweed reaches the shore, and on the beach cleaning continues daily with tractors and staff.

The impact on businesses

Hotels, restaurants and shops report falling revenue. On top of the effect of the algae come reduced air connections, international geopolitical tensions and concerns over security.

The air traffic figure measures the scale of the phenomenon. Between January and May 2026 the region's airports lost more than 645,000 passengers compared with the same period in 2025.

Tulum is the worst affected town, with sales down by as much as 60%. Many businesses are operating at a loss. Some have suspended trading temporarily, others have closed for good.

The government of Claudia Sheinbaum has announced an investment of 115 million dollars. The money will go towards new collection vessels, further floating barriers and stronger existing collection systems.

The quantities arriving explain why the response requires resources on this scale. At peak times more than nine thousand tonnes of sargassum reach the Caribbean coasts each day. That is four times the volume of 2025 and 27 times the historical average.

Sargassum forms in the tropical waters of the Atlantic and is carried by currents towards the Caribbean and the Gulf of Mexico. Its growth is encouraged by rising ocean temperatures and by the excess nutrients that intensive agriculture discharges into the sea.

The two causes identified operate far from where the problem appears. That limits the effectiveness of the measures taken on the coast, which address the effects rather than the origin of the phenomenon.