Mountains of algae grow on the Caribbean coast of Mexico

TULUM, Mexico (AP) — Removing foul-smelling sargassum algae from some beaches on Mexico’s resort-packed Caribbean coast has become not only a nightmare, but possibly a health threat to the workers who do it. not mounds.

The decomposition of sargassum, which is actually algae, generates hydrogen sulfide gas. In small amounts in open areas, it’s not much more than a nuisance odor: sulfurous, like rotten eggs.

But in the amounts seen in once-paradisiacal beach towns like Playa del Carmen, Tulum and Xcalak, scientists say it can be dangerous for workers with respiratory problems as they collect the seaweed without a mask in the scorching heat. . This year appears to be on track to be even worse than the peak sargassum year of 2018.

Ezequiel Martínez Lara is one of thousands of workers who toil six to eight hours a day loading piles of sargassum onto forklifts and then hauling them from the beach to a growing pile on a neighboring street.

Martínez Lara used to earn up to $50 a day guiding sport fishermen on catch-and-release outings, but now he earns less than half for collecting about 40 wheelbarrows of sargassum every day.

It’s a Sisyphean task on a beach north of Tulum, where huge sheets of seaweed float just offshore.

“If we clean everything today, tomorrow there will be more washing,” said another worker, Austin Valle.

But workers like Martínez and Valle are exposing themselves to more than just the blazing sun, says Rosa Rodríguez Martínez, a biologist from the coastal town of Puerto Morelos who studies reefs and coastal ecosystems for the National Autonomous University of Mexico.

“At the university we have begun to measure the amount of gases that sargassum produces when it is scraped,” said Rodríguez Martínez. “In one place (in a pile of decomposed seaweed) it reached 56 parts per million. That is very high. Above two, that can be dangerous for people with respiratory problems.”

“I ran out” of the place, he said.

Martínez Lara cannot afford to avoid hydrogen sulfide gas. Like almost all other sargassum workers on the coast, he does not have a mask, gas sensor or medical attention. He works for the salary of the person who owns the beachfront house.

“When the sargassum rots, it gives off a very strong smell of acid, and it is very annoying when you breathe it; it hurts a lot,” Martínez Lara said. He said that he takes simpler precautions.

“We try to clean it up (the beach) as quickly as possible … to remove it when it’s as fresh as possible,” he says.

A 2019 article in the Journal of Travel Medicine includes the ominous warning: “More chronic exposure to these gases can lead to conjunctival and neurocognitive symptoms, such as memory loss and balance problems, as well as non-specific symptoms, such as headache, nausea and fatigue. .”

The Florida Department of Health, on the other hand, says that “Hydrogen sulfide levels in an area such as the beach, where large amounts of airflow can dilute levels, are not expected to be detrimental to health.”

The sargassum problem is not as bad for tourists as it is for workers. But it’s not nice either.

Ligia Collado-Vides, a marine botanist at Florida International University who specializes in the study of macroalgae such as sargassum, said, “If you’re swimming for a while, it shouldn’t be a hazard at all,” but added that the tiny cousins ​​of jellyfish known as hydrozoans often inhabit mats of sargassum.

“If you’re going to be out there for a long time playing in the sargassum, you can get many, many, many bites from hydrozoans and those are toxic,” he noted, adding that long sleeves — something hardly anyone wears on the beach — could help. .

Sarah Callaway, a tourist from Denver, Colorado, was practically confined to playing with her children in the pool in front of her rented beach house.

“The property is beautiful, but we were automatically struck by … the smell,” Callaway said. “The smell is really pungent and very strong. And then, yes, we were disappointed with the amount of sargassum seaweed that is here.”

“Children have tried to get into the ocean, but then they are overwhelmed by it. So we haven’t really gotten to do the beach part, that’s why we came,” he said.

It will also affect locals who depend on the tourist trade. Hundreds of thousands of people have migrated to the coast in recent years in search of better-paying jobs, but some may now be considering leaving.

Valle, the algae cleaner, said that one of his friends in Tulum has been thinking of leaving his snack stand business because sales are down so much.

It is difficult to measure the impact on tourism. The Caribbean coast suffered a drop in visitation during the coronavirus pandemic, but because Mexico never declared travel restrictions, testing requirements or mandatory mask rules, Americans have kept coming.

International tourism to the country as a whole exceeded pre-pandemic levels in the first half of 2022, with 10.26 million visitors from January to June, 1.5% higher than the 10.11 million tourists who arrived in Mexico in the first half of 2019.

Mexico’s strongest presentation was with US tourists. The number of Americans arriving by air in the first six months of 2022 was 6.66 million; that is, 19.1% more than in the same period of 2019.

But that boom may be slowing. Grupo Financiero Base noted in a research report that international tourist arrivals in June 2022 were down 13.8% from June 2019 levels. It is unclear what (sargassum, inflation, or the war in Ukraine) may have caused that drop.

And overall tourism spending remains below pre-pandemic levels.

The picture is mixed because some of the more developed resorts, like Cancun, have not suffered as much from sargassum as lower-key resorts further south, like Playa del Carmen and Tulum.

Ocean currents and islands like Isla Mujeres protect Cancun from much of the floating sargassum. Given the large number of large hotels in Cancun with large cleaning staff and money to deploy floating barriers, the sargassum that arrives is cleaned up more quickly.

The jury is still out on the floating booms, intended to catch sargassum mats in the sea before they reach the beach.

“When the sea is calm, all kinds of barriers work,” said Rodríguez Martínez. “When there are waves, none work.”

Some tourists like the area so much that they keep coming back.

“I will absolutely come back. We love it here,” said Jeff Chambers, a tourist from Palm Desert, California, who was strolling down Tulum’s main coastal street. “We like things a little slower.”

Some locals like Víctor Reyes, who works in real estate in Tulum, are more optimistic about the seaweed, noting that it’s not as bad in the winter months.

“In winter it is better. In November, when the tourists want to come, the sargassum ends,” says Reyes.

As bad as sargassum is for people, and Collado-Vides stresses much more study is needed, it’s much worse for seagrasses, fish and other marine life suffocated by algae falling to the bottom, decomposing and creating anoxic layers. or devoid of oxygen similar to dead zones.

“The sargassum stays there and goes down into the water column so that no one sees it, but deep down it creates anoxic conditions,” he said.

Recounting a recent monitoring expedition, Collado-Vides said: “It’s really terrible… the number of vertebrates, the number of crabs, the number of dead fish in just one square meter square.”