Sargassum: Friend or foe?

  • 26 March 2021
1024 768 Mangrove Maniacs Bonaire

Sargassum is a floating seaweed which can be found around the world.  Naturally it forms its own special habitat, home to a wide variety of animals which have evolved to specifically live within its dense floating forests.  Occasionally, small portions of this seaweed would break off and make its way onto neighboring beaches.  Decomposition of this seaweed on dunes would provide a much needed influx of nutrients, helping to link the land and sea.

Within the Caribbean, scientists have known about the Sargasso Sea for years. This area is found in the Atlantic and is responsible for the large amounts of sargassum washing onto the shores in the north Caribbean and southeastern coast of the US.  New research has also indicated the emergence of a second sargassum patch known as the North Atlantic Recirculation Region.  It is believed this patch has developed due to an influx of agricultural fertilizer used in the Amazon, eventually making its way into the Atlantic. Unfortunately, deteriorating water conditions and excess pollutions in our oceans means that this seaweed has grown out of control.  Now, uncontrolled amounts are filling in bays and lagoons, smothering seagrass beds, coral reefs and beaches.  Piles of decomposing sargassum can add heavy metals and toxins to the waters and beaches.



On Bonaire we’ve already seen the negative impacts of this with degraded seagrass beds and mangroves in areas which accumulate sargassum the most.  The Mangrove Maniacs are working together with the park authority STINAPA to help remove sargassum as soon as it arrives, minimizing the ecological damage it can inflict on these areas.  There is still much to be learned about the impact these influxes will have on coastal habitats.

You can find related studies on sargassum on our related study page or follow the Mangrove Maniacs on facebook to keep up to date on future influxes.