In small quantities or open waters, sargassum does not pose a significant risk to human health or marine ecosystems. However, that’s no longer the case with massive volumes of seaweed washing ashore, poisoning shallow waters and killing marine life.
Although sargassum season in Mexico is essentially over, authorities reported this week the detection of high levels of heavy metals, arsenic and microplastics, linked to this algae.
According to Esteban Amaro Mauricio, Director of the Quintana Roo Sargassum Monitoring Network, when sargassum reaches beaches, it begins to decompose rapidly, releasing toxic gases such as ammonia, hydrogen sulfide, carbon dioxide and carbon monoxide.
But it doesn’t stop there. When sargassum comes into contact with heavy metals, these gases turn the seaweed into hazardous waste, which must now be handled accordingly.
Amaro Mauricio emphasizes that the most effective way to reduce health risks is to collect most seaweed while it’s still in open waters before it becomes harmful.
Despite the multidimensional issues associated with the sargassum phenomenon, in recent years, both the private and public sectors have developed innovative techniques to separate heavy metals from algae, allowing the remaining material to be used in various commercial products.
Although the 2024 sargassum season in the Mexican Caribbean was not as dramatic as in previous years, large amounts of the foul-smelling seaweed still affected numerous beaches across popular destinations like Cozumel, Playa del Carmen and Tulum.
This year, the arrival of algae began earlier than usual, with significant accumulations reported as early as February on Tulum and Playa del Carmen beaches.
Meanwhile, Cancun’s Hotel Zone saw lower levels of sargassum, allowing beachgoers to enjoy some spots of clean water.
According to official reporters, the 2024 sargassum season “ended” earlier than expected due to a change in Atlantic Ocean currents, which diverted most of the algae toward the Lesser Antilles.
It’s worth noting that each year, 15 to 20 million metric tons of sargassum are produced in the Sargassum Sea, of which 10% reaches the coasts of Quintana Roo.
On Wednesday, members of our Facebook group, Mexico Sargassum Seaweed Updates, reported that sargassum is nearly nonexistent on Cancun, Tulum and Playa del Carmen beaches.