Toxic Threat: Sargassum Seaweed Invasion in Quintana Roo

The Citizen Sargassum Observatory has identified a significant build-up of pelagic sargassum seaweed approximately 100 kilometers east of the Guanaja and Roatán islands in the Honduran Caribbean. It is anticipated that sea currents and winds will carry this large mass of seaweed to the waters of the Mexican Caribbean within the next few weeks.

The sargassum season in Quintana Roo typically runs from April to September, with May seeing the highest levels. The observatory is closely monitoring this large patch of sargassum, using the Optical Oceanography Laboratory of the University of South Florida (USF) for tracking.

Under favorable conditions, this sargassum patch could double in size in less than 20 days, posing a potential risk. As the seaweed decomposes on the shore, it consumes significant amounts of oxygen, leading to oxygen depletion and the release of toxic gases such as hydrogen sulfide and methane. These gases are harmful to human health and can result in the mass death of many species.

The decay process also releases excess nitrogen and phosphorus, which act as fertilizers for further seaweed growth. This leads to the production of leachates, sulfuric acid, and arsenic, contributing to the unpleasant, rotten smell often associated with some tourist destinations, thereby impacting their attractiveness.

The Citizen Sargassum Observatory has also highlighted another issue: the mismanagement of sargassum. This results in the seaweed acting as a pollutant, introducing heavy metals such as cadmium and lead, as well as harmful bacteria, into the environment.

The Observatory is calling on relevant authorities to take action to mitigate the impact on wildlife and the tourism sector.