Sargassum: A Tangled Mess on Beaches but a Powerhouse of Energy Potential

Sargassum is a type of marine macroalgae that gives fish, shrimp, crabs, and turtles a place to live. In recent years, it has proliferated, which hurts the tourism industry in the Caribbean because there are so many of them on the beaches. It is hard to control because it gets around environmental controls.

The factors identified by experts as the cause of the increase of this marine plant are the increase in nutrients, water temperature, and winds. The most solid proof that this macroalga is too much is that 24 million tons of it moved from the Caribbean to the Gulf of Mexico just in August 2022.

The president of the National Authority of Maritime Affairs (Anamar), Jimmy García Saviñón, considered that the best use that can be given to the sargassum is the generation of electric energy, as they propose to do in Guadalupe Island soon, where a plant will be installed to generate electricity from this macroalgae.

The official explained that he was in Morocco, where he took a container of sargassum to test how it can be converted into an energy-generating product through a process carried out in a specialized plant.

"A container of sargassum was taken to Morocco to do the test; with that plant, the sargassum is dried, the second step is to crush it, then compress it, and the fourth step is to convert it into charcoal." "This coal has another process that they do not have in Morocco, an additional process that is used for energy production, through pyrolysis."

Pyrolysis is the chemical decomposition of organic matter using high temperatures.

Anamar is promoting the use of sargassum as an energy generator as a way to look for alternatives to the problems that this seaweed generates and its economic impact. "We are promoting that so that the private sector can invest because the sargassum problem is an economic burden because there is no way it can be controlled."

The area from which the sargassum is arriving in the Caribbean is between Brazil and Africa, and in about 72 days it reaches the Dominican coast. "The nutrients from the Amazon, the dust from the Sahara desert, and the warming of the sea all affect the sargassum." "All of these things have caused it to be made in too large a quantity," he said.

For those interested in seeing the behavior or route of the sargassum, Anamar has a weekly forecast that is posted on the institutional portal anamar.gob.do.

Turning Sea-Waste into Soil-Gold: The Battle Against Sargassum

Since 2011, when a lot of sargassum started washing up on the coasts of the Caribbean, people have come up with different ways to use it. One of these was intended as fertilizer for crops, but Anamar's technicians didn't like it because it would have to go through a process to remove heavy metals and get rid of salt.

"For collection at sea, there is a project that is being executed in Cap Cana and Punta Cana with the company SOS Carbon, which was a study that the company did with the Massachusetts Institute of Technology and Anamar, and that consists of using small boats with a mesh, and that collects a certain amount.

"Then the mesh is dismantled and taken to the truck that transports it." "But that is a palliative because then comes the final disposal of the sargassum, and what we are doing is burying it in the sand or simply throwing it in a vacant lot," he noted. When asked about the putrid smell produced in marine areas where there is a lot of accumulated sargassum, he said that it is arsenic decomposing, contaminating the areas where it is deposited.

Regarding its application in agriculture, García Saviñón explained that, without treatment, it cannot be used as a fertilizer. "When you dump it on a piece of land, you are salinizing the soil and contaminating it with the heavy metals that this nutrient produces," said the president of Anamar.

A Dilemma at Sea - Balancing Problem & Protection of a Nutrient-rich Ecosystem

Andrea Valcárcel, a marine biologist, said that sargassum is a strong dilemma because it has become a problem, but it is also an ecosystem that is full of nutrients and has heavy metals.

The problem of sargassum is complex, the expert assures, pointing out that "it is true that it is a problem on the coasts, but it reaches a legal point because worldwide it is considered a protected ecosystem because there are species that only live there, such as fish, crabs, and eels."

"It is a delicate issue; when the sargassum is in the high seas, there is no problem, but when it comes to stranding on the beaches, it has almost no use." "The issue is at what point you can pick it up on the coast, but at the same time you are destroying that ecosystem." Sargassum needs a specific temperature to reproduce, and it used to happen twice a year, but now it is almost permanent.