What is sargassum

The term sargassum groups several species of brown algae within the genus Sargassum . It includes several species such as Sargassum vulgare , Sargassum filipendula or Sargassum cymosum . They are large in size and their structure is divided into the classic rhizoids, stipes and laminae, analogous to the roots, stems and leaves of vascular plants. Some species have gas-containing vesicles that improve their buoyancy.

The algae of the genus Sargassum are distributed throughout tropical and temperate zones, and contribute significantly to the biomass of many coastal areas, offering food, substrate and protection to other marine plant and animal species. For example, loggerhead turtles ( Caretta caretta ) use it as protection for their eggs until hatching, and several species of crustaceans and fish have specifically adapted to take advantage of the resources it offers. Specifically, it plays an important role in the migration of some eels, such as the European eel ( Anguilla anguilla ) or the American eel ( Anguilla rostrata), which specifically travel to the Sargasso Sea to lay their eggs.

Sargassum has a great capacity for growth and reproduction (it can double its biomass in less than three weeks), due, among other factors, to its ability to reproduce vegetatively, that is, without the need for organs with a specific reproductive function.

The sargassum that reaches the Caribbean beaches comes mostly from the so-called Sargasso Sea . It is located in the Atlantic Ocean, near the coast of Brazil . The extension of the Sargasso Sea is variable, since it is defined by the amount of algae that is present at that moment and by the marine currents. It is delimited by the Gulf Stream, the North Atlantic Current, the Canary Current and the Equatorial North Atlantic Current.

As a curiosity, to say that society has always maintained a difficult relationship with the Sargasso Sea. It has been named in different nautical texts since the 15th century, due to the fact that it was an area of ​​difficult navigation. The great accumulation of algae, the virtual absence of winds and confluent marine currents made it easier for the sailboats to be stranded in its waters, with little chance of departure.

Today, sargassum that dies loses its ability to anchor to the substrate and other plants, and is dragged by marine currents to the waters of the Caribbean Sea , among others. When it arrives, the decomposition process, in which substances such as sulfates are released, causes its characteristic bad smell.

The phenomenon does not show a definite chronology; it can be presented at any time. However, there has been an upward trend in both duration, intensity and frequency since 2013.

These have been some of the most affected areas:

• Sargassum in the Riviera Maya: this area has undergone intense modifications due to sargassum, such as the installation of floating containment barriers and monitoring stations.
• Sargasso in Cancun: hospitality personnel in these regions have warned of up to 60% of economic losses due to this phenomenon.
• Sargasso in Playa del Carmen: in Playa del Carmen there are already hotels that have adapted to this recurrent invasion, building pools that stop the entry of detritus.
• Sargassum in Tulum: on this beach the sargassum stain has reached up to 400 m ² .

These examples are not exclusive to these beaches, but can be extrapolated to other affected coastal areas.

We can transform a threat into an opportunity. In 2018, at the request of the Mexican government, a group of scientists from UNAM formed a permanent working group to try to provide solutions to this problem on the beaches of Quintana Roo. Efforts have been made to collect sargassum, for example with the installation of barriers, and to monitor the phenomenon, both to give early warnings and to rule out possible human health problems.

Finally, these and other scientists have proposed several opportunities for the use of Sargassum or sargassum algae :

• Generate biomass: biomass can be used as fuel or for the generation of biofuels, etc. Here you can learn about what biomass is and what it is for .
• Use as a fertilizer: sargassum has a high content of nitrogen and other important nutrients, which can be used to fertilize fields if done properly.
• Extraction of important materials for the industry: sargassum is especially rich in alginate, a polysaccharide that is often used as a thickener in food products and even cosmetics.

Thus, managed effectively, we can reduce the impact and even benefit from this environmental nuisance.

If you want to read more articles similar to What is sargassum , we recommend that you enter our Biodiversity category .