Caribbean Invasive Alien Species Network

The growing sargassum problem

Sargassum seaweed (Sargassum muticum) also known as wireweed is an invasive species of seaweed that has been known to grow in masses due to high concentrations of phosphorous and nitrogen. It has negatively affected countries that depend on Tourism, as the seaweed can spread for miles on beaches, and decaying seaweed can be hazardous to human health, including costly to clean up.

Caribbean countries that depend on coastal and marine areas have suffered great economic losses across the wider Caribbean region due to the growing sargassum problem. Those countries that rely on Tourism, have reported desertion of restaurants and hotel cancellations because of the smell of decaying sargassum. The smell of the decaying sargassum has been known to cause symptoms of headaches and nausea among beachgoers and locals.

The brown algae of sargassum float freely on the ocean surface and the growing problem of sargassum is that it is exacerbated by the release of fossil fuels and runoffs from urban areas. It negatively impacts biodiversity especially nesting sea turtles, who lay eggs on the beach. Marine life that is exposed to the toxic compounds of this seaweed due to its large algae blooms may suffer, as the blooms prevent sunlight from reaching coral reefs.

There have been notes on recorded damages among electronic appliances of coastal hotels (TVs, computers, air-conditioning units) because of prolonged exposure to high concentrations of hydrogen sulfide. Observations have been noted within the coastal population as fishermen find it difficult to navigate water because the sargassum entangles into their gear.

Managing sargassum is a priority among Caribbean countries and ramped-up efforts to keep beaches clean included the use of nets and floating barriers, beyond the surf line, to redirect and catch the sargassum before it can wash ashore. Some countries have started to collect the sargassum by boats and use heavy-duty tractor-style machines to remove the invasive seaweed from the shores.