A type of foul-smelling algae called sargassum won't stop washing up on the shores of Mexico's most popular tourism beaches like Cancun and Tulum, The Wall Street Journal reported.

These resort-packed beaches are part of of Mexico's $100 billion tourism industry.

Resorts now spend millions annually attempting to get rid of the smelly algae.

Experts say the amounts of sargassum washing to shore could only get worse because of climate change, destroying entire ocean ecosystems as more algae grows and spreads.

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In Mexico, the $100 billion tourism industry has been a huge benefit to the country's economy, but that could all change due to foul-smelling algae overtaking the country's most prized tourist destinations, The Wall Street Journal reported.

At resort-filled Mexican beaches like Tulum, Cancun, and Playa del Carmen, algae called sargassum washes to shore in massive quantities, deterring tourists because of its unpleasant smell. In one case, the smelly sargassum washed to shore in a mound the size of the island of Jamaica.

"I have never seen sargassum arrivals in such massive quantities," Susana Enríquez, a reef systems expert at Mexico's National Autonomous University in Puerto Morelos, told The Wall Street Journal.

For tourists, the amount and stench of the substance has deterred them from returning to Mexico in recent years. In the cities of Cancun and Puerto Morelos, for example, hotel occupancy is down 3.5% from last year, even with some hotels decreasing room rates by 15% to 25% year-over-year.

According to Roberto Cintrón, president of the Cancún and Puerto Morelos Hotel Association, hotels now spend millions annually in an attempt to rid their beaches of sargassum, hiring workers to collect and cart the seaweed to offshore locations.

Since May 2019, Mexico's Navy reported collecting 218 tons of sargassum and the country's president, Andrés Manuel López Obrador, pledged $2.5 million in government funding to help the situation.

But the influx of sargassum could ultimately be out of the country's hands, as experts believe climate change could have to do with the problem.

The algae is unrelenting but experts believe it could only get worse

"You can clean up a beach, get it clean, imagine starting at 6 a.m. and by 11 a.m. you don't have any algae, and by 7 p.m. when the sun sets, it's full again," Adrian Lopez, the president of Quintana Roo's employers' federation, told Associated Press.

Mexico isn't the only place to experience such large amounts of sargassum. In 2018, scientists found a whopping 5,500 miles worth of sargassum floating in the Caribbean Sea and the Gulf of Mexico, according to The Wall Street Journal. They dubbed this stretch the "Great Atlantic Sargassum Belt" and today it contains more than 10 million metric tons of algae.

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This phenomenon may be due in large part to deforestation efforts in the Amazon rainforest. Runoff may have put nitrogen and other nutrients into the ocean and lead to an overgrowth of sargassum, that once grabbed by currents, finds its way to popular beaches. Even more worrisome is the sargassum's ability to change oxygen levels in the ocean and destroy entire ecosystems in the process.

Scientists also believe climate change could have lead to the increase in sargassum, although they aren't yet positive.

"Because of global climate change we may have increased upwelling, increased air deposition, or increased nutrient source from rivers, so all three may have increased the recent large amounts of sargassum," Chuanmin Hu, a professor of oceanography at South Florida University's College of Marine Science, told Associated Press.

Regardless of the cause, Mexico's beaches are likely forever changed.