Massive Flotillas of Putrid Seaweed Wash Up in Caribbean and S. Florida, Threatening Beaches

Beaches from Florida to French Guiana in S. America have been plagued in recent years by massive influxes of Sargassum blooms, threatening not only the ecosystem but also tourism as resorts battle tons of the seaweed-like grass washing up on beaches on a daily basis. This year is gearing up to be one of the worst Sargassum invasions in recent memory.

Sargassum is abundant in the ocean, originating in the Sargasso Sea, a region of the North Atlantic. The seaweed forms floating rafts that can stretch for miles. The leaves and branches contain gas-filled berry-like structures called pneumatocysts that make the plants buoyant and able to float on the surface of the water. The floating masses of Sargassum provide an essential habitat for fish, sea turtles, birds, and hundreds of other sea creatures.

But in recent years Sargassum has been washing up on shores in mass quantities, creating smelly piles on beaches and distressing tourists. The Caribbean has been hardest hit, but the Sargassum has become a nuisance in Florida and off the West Coast of Africa as well. (See map of the affected areas below.) While normally harmless to humans, when it washes up on shore, the seaweed and animals contained within quickly begin to die and decompose, leaving a rotten egg smell in its wake.

Brian LaPointe, a research professor with Florida Atlantic University-Harbor Branch Oceanographic Institute, told the Miami Herald last month, “I think the potential exists that the situation could worsen in parts of Florida.” LaPointe added, “We’ve seen problems in the Florida Keys in the past couple years… It’s gotten to the point in places where people will avoid swimming. It’s not something you’d really want to swim through or in."

Brigitta Ine van Tussenbroek, a scientist at National Autonomous University's Institute of Marine Sciences and Limnology, told Mexico News Today that the arrival of Sargassum on Mexico's Caribbean coast in mass quantities could cause a serious environmental disaster. Since 2015, she said, the quantity of Sargassum on beaches in Quintana Roo has doubled.

“There could be an ecological disaster in the short term and by extension also a socioeconomic disaster because all the industry here in Quintana Roo depends on tourism,” Ine van Tussenbroek said. She explained that both climate change and shifting ocean currents are thought to be possible causes of the influx of the seaweed.

Subtropical storm Alberto brought tons of the putrid-smelling seaweed to the shores of Mexican beaches in May, but the influx has continued months after Alberto subsided. Owners of large hotels in Quintana Roo reportedly are spending upward of $54,000 US per month on beach cleanup. The Mexican government pledged $3.08 million US for Sargassum removal, and by mid-June, nearly 100 tons of the seaweed had been removed from Mexican beaches.

While planning for our annual fall trip to Belize, my husband and I considered spending a couple of days on Ambergris Caye, an island east of the mainland, before heading south to Hopkins, but travelers on Trip Advisor strongly warned against it due to the heavy influx of Sargassum.

Sarah L. wrote, "I just arrived today and it's bad. Piles of it on the beach and the smell is overwhelming."

According to Jean H., "The smell is worse in some locations than others. I’ve been ‘hiding’ from the smell in my bedroom with the windows closed." She added that the smell was worse the farther south you go. "Many of the resorts are working hard to get rid of the stuff, but, it’s been pretty overwhelming over the past week."

A user who goes by the name of Beach Dix wrote that the resorts cannot keep up with the seaweed. She said it "smells worse in some places than others, but it is pretty significant," interfering with swimming in the area. "Even got mixed up in patches of it while trying to snorkel," she said.

Pdx Julie said that the Sargassum basically ruined her vacation. "Even if a resort rakes up the seaweed, chances are the property next door doesn't," she said. "The worst thing about the Sargasso is the stench. The smell of rotten eggs is horrible and almost everywhere. It really prevented us from doing what I came here to do - hang out on a lounge or hammock by the water. We could even smell it in our room at night with all the windows closed."

Although the resort we visit in Hopkins doesn't have nearly as much Sargassum as areas to the north, removing the piles that wash up on the beach every morning is a labor-intensive task. Every morning at sunrise men with rakes and wheelbarrows arrive at the beach to remove the day's accumulation, hauling away load after load after load of the heavy plant formations.

According to a resource guide by the Caribbean Alliance for Sustainable Tourism (CAST), there are a variety of potential beneficial uses for seaweed that has been removed from beaches. "Sargassum is an excellent medium for use as landfill. It can be used to build up dunes and beaches to combat the threat of beach erosion," the guide explains. It can be used as fertilizer and compost as well if properly cleaned.

In addition, Sargassum is sometimes incorporated into food dishes. "Seaweed is often used in Asian-inspired dishes and has a somewhat bitter taste that many people enjoy," the guide explained. "Some Sargassums can be cooked in lemon juice or coconut milk and served alone or as a side to meat and fish."

It doesn't appear that the problem is going away anytime soon. Governments and private business owners continue to grapple with the seaweed, researching best practices for Sargassum removal, but in the meantime, tourists might want to consider staying away from the affected areas, at least for the time being.

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