Excess seaweed on the shore confuses nesting turtles, traps turtle hatchlings, creates noxious H₂S fumes, causes beach erosion from manual removal, and brings trapped plastics ashore.

At the same time, excess sargassum in the water:

- Reduces sunlight for flora & fauna
- Creates anoxia from H₂S gas
- Degrades reefs
- Reduces biodiversity
- Provides a “raft” for invasive species

Sargassum is not native to the Mexican Caribbean so the environmental effects are huge and adverse. It reduces the visibility of the water column, blocking algae and fauna from absorbing sunlight. The decay of tons of seaweed often leads to anoxia (oxygen-deprived conditions in the water) and the build-up of poisonous hydrogen sulfide gas, which is harmful to most marine animals. This, in turn, leads to degradation of coral reefs and associated ecosystems as well as to biodiversity loss.

Enormous “sargassum rafts'' entrap plastics & hazardous medical wastes and also contain high concentrations of arsenic & heavy metals. These rafts may also be introducing exotic and invasive species to the area, including the invasive Lion Fish.

Beach removal activity contributes to sand loss and significant beach erosion.

The sargassum in our waters comes not from the Sargasso Sea but from a monstrous new area in the Atlantic that scientists are calling the GASB (Great Atlantic Sargassum Belt). To help you understand the enormity of this problem, we’ve posted articles about the GASB on the News Page. The GASB is fueled by agricultural fertilizers and untreated sewage flowing into the Caribbean and Atlantic. Barely 30% of wastewater in Mexico’s Mayan Riviera is treated.

And here in Akumal, so famously known as “The Place of the Turtle”, there is particularly sobering evidence that thick accumulations of sargassum on beaches can create significant problems for nesting sea turtles and can prevent hatchlings from reaching the shorebreak.

(NOTE: If protecting turtles is an issue that concerns you, please review the relevant articles in the Resources Section and then reach out to us at HMBBarrierProject@gmail.com. We’d really appreciate your input on this topic!)