The Stench of Sargassum Season: How Seaweed is Threatening Mesoamerica

Photo Credit: Teresa Wood

Do you smell that? It’s the stench of rotting eggs…lingering for half a mile inland from the Caribbean shoreline. It’s a stinky reality of this year’s sargassum bloom, or in other words, the overload of seaweed that is washing up on beaches in parts of Mexico, Honduras, Belize, and other nearby areas. 

What is Sargassum? And Why is There So Much of it? 

Sargassum is a seaweed that floats across the ocean in large island-like masses. While floating, the sargassum has many benefits and provides shelter and food for marine life. But once the mass strikes land, it starts to decompose. 

While sargassum blooms are a natural occurrence, climate change and direct human impact have led to an explosion of new nutrient-dense seaweed, all accumulating on the beaches in the Mesoamerican Region. The seaweed grows in the Amazon River area and continues to bloom and move with the current, until arriving in the Caribbean. The combination of increased dust blown westward from mining and desertification in the Sahara, mixed with the fertilizer runoff in the Amazon, and overall warming temperatures has led to the perfect conditions for blooming seaweed. 

“The seaweed grows quickly,” says Javier Pizaña-Alonso, CORAL’s Program Manager in Cozumel.  “Under these perfect conditions, blooms can double in size in about 18 days. It can become an issue, depending on how long the blooms drift in the ocean.” 

How Does Sargassum Impact Mesoamerica? 

Excess of nutrients found in the seaweed doesn’t just smell bad—it also threatens the health of coastal marine environments. The seaweed is rich in nitrogen, sulfur, ammonium, and heavy metals due to excess fertilizer runoff in the Amazon River, which is a result of rainforest deforestation and increased agriculture.

“When the sargassum washes up on shore, it degrades and creates a brown tide. This impacts water quality,” says Pizaña-Alonso. Poor water quality is dangerous for animals in the ocean, including our coral reef ecosystems. Without clean ocean water, there is potential for excessive algae growth, which can quickly take over reef-building corals and destroy the home of more than one million marine species. Furthermore, too much sargassum can smother coral reefs that are close to the shoreline and impact the habits of other animals.

Photo Credit: Teresa Wood

And the environmental impact isn’t the only concern. Too much sargassum may also affect the local economy in Mesoamerica, which relies heavily on tourism. “Travelers don’t like the smell and it affects our beautiful beaches,” says Pizaña-Alonso. 

What Is Being Done to Address the Problem? 

There are a lot of factors involved when it comes to solving the sargassum problem. According to Pizaña-Alonso, in Quintana Roo, the navy is trying to collect the seaweed before it comes to shore. Meanwhile, in other affected areas, like Roatan, Honduras, the government has defined a task force and different sectors are advocating for a state of emergency, which will allow for additional funds to be used to address the situation.

Despite some controversy, there is also research and testing to see if it is safe to recycle the sargassum. Some are proposing to turn parts of the seaweed into animal feed or mulch. There’s even been experimentation with the idea of using sargassum to make low income homes, notebooks or shoes.  

As a next step, Pizaña-Alonso, would love to get involved with the government’s efforts and offer his expertise in marine science. He is also urging governments, corporations, and individuals to learn about this problem and why it is occurring in the first place. By simply lowering our carbon footprint and advocating for the elimination of destructive tactics, like deforestation and mining, we allow for a more balanced planet, and ocean for all. 

To learn more about Cozumel’s effort to save coral reefs, visit our programs page here.

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