Florida, USA: Seaweed mass expands, reaches record tonnage. Messy Florida beaches ‘inevitable’

Beached sargassum surrounds a pair of sunbathers in Boca Raton on March 31, 2023. ROBYN WISHNA

We already knew South Florida beaches were bracing for a surge of seaweed, but the mass of seaweed looming in the Atlantic Ocean is now officially record-breaking. The Great Atlantic Sargassum Belt — the official name for the collection of floating brown seaweed that sprawls across 5,000 miles from the Gulf of Mexico to the west coast of Africa — contained about 13 million tons of seaweed by the end of March, according to researchers at the University of South Florida’s Optical Oceanography Lab who have been monitoring the sargassum belt via satellite.

This map from the University of South Florida Optical Oceanography Laboratory shows the sargassum bloom as of March 2023. Red areas have a higher density of seaweed. Courtesy of the University of South Florida Optical Oceanography Laboratory

That’s a new record for this time of year. Though it remains strung out over thousands of square miles of open ocean, it’s an omen of smelly, slimy beach days to come. In some places, including Boca Raton and Fort Lauderdale, large masses have already washed ashore or been spotted by boaters just offshore. “Major beaching events are inevitable around the Caribbean, along the ocean side of Florida Keys and east coast of Florida, although the exact timings and locations are difficult to predict,” the USF researchers wrote in their latest monthly sargassum bulletin.

A mat of sargassum bobs in the water off the coast of Fort Lauderdale just north of the Port Everglades inlet on April 2, 2023. Robyn Wishna

We only have ourselves to blame. Human activity and climate variability have caused sargassum blooms to get bigger since about 2011, according to Chuanmin Hu, a USF oceanography professor who is part of the sargassum observation team. Fertilizer runoff and sewage dumped into the ocean have fed sargassum more nutrients, while climate change has warmed ocean waters and given the seaweed a more hospitable environment in which to grow.

Beachgoers step around a mat of sargassum that washed ashore at Fort Lauderdale Beach near Sunrise Boulevard on March 31, 2023. Robyn Wishna

So far this year, South Florida beaches have only been hit sporadically with seaweed pileups. But it’s still early: The local seaweed season typically runs from May to October, with the peak coming in June and July, according to Tom Morgan, chief of operations at Miami-Dade County Parks, Recreation and Open Spaces. Miami-Dade County’s spending on seaweed cleanup has risen from $2.8 million during the 2020 sargassum season to $3.9 million during last year’s season. Now the county is asking the state Legislature for an extra $2 million to fund sargassum removal, which would bring this year’s total spending on seaweed cleanup to about $6 million. “I was just up there [in Tallahassee] a couple of days ago talking about this,” said Miami-Dade County Mayor Daniella Levine Cava, “because we’re spending in the range of $4 million per year and we are anticipating the need to spend more with the additional arrival” of seaweed on the beaches this year.

Heavy equipment starts cleaning seaweed from the seashore after a press conference by Miami-Dade County and City of Miami Beach elected officials announcing the county’s removal operation for sargassum/seaweed on Miami Beach on Friday, Aug. 2, 2019. Pedro Portal pportal@miamiherald.com

Most of Miami-Dade County’s seaweed budget goes toward removing the sargassum that piles up in four hot spots: beaches in Haulover just north of Haulover Cut; beaches in Bal Harbour just south of Haulover Cut; Miami Beach between 26th Street and 31st Street; and the beaches alongside South Pointe jetty. Last year, the county cleared 18,000 cubic yards of sargassum from these four areas. Most of it wound up in the county’s rapidly filling landfills. “Obviously, that’s not a great solution because the landfills have limited space,” Levine Cava said. The county is looking into the idea of composting the seaweed rather than dumping it, but has concerns about sargassum’s reportedly high concentrations of arsenic and other heavy metals, according to Lisa Spadafina, who runs the county’s Department of Environmental Resource Management. “Those are the things that we’re looking to address so that we’re not creating another problem by composting,” Spadafina said.

Sargassum washes ashore at Fort Lauderdale Beach near Sunrise Boulevard on March 31, 2023. Robyn Wishna

To be clear, sargassum itself is harmless to humans. It does harbor jellyfish, sea lice, and other stinging creatures that can irritate the skin — and the hydrogen sulfide it releases when it rots in the sun can aggravate breathing problems for people with pre-existing respiratory conditions, in addition to smelling like rotten eggs and making the beaches generally unpleasant for swimmers and sunbathers. But it’s also an important habitat and food source for many sea creatures and poses no threat to human health when beach maintenance crews promptly remove it or use machines to cut it up and mix it into the sand. During the peak of the sargassum season, Miami-Dade County crews do this each morning just after sunrise, after they’ve made sure there are no sea turtle nests nearby that might be disturbed by the heavy machinery. The 13 million tons of seaweed currently bobbing in the Atlantic Ocean won’t all come ashore on Florida beaches, and the fraction that does land here won’t come all at once — not even in hot spots. “Even Miami Beach won’t receive sargassum every week or every month,” said Hu. “That will depend on the tides and the wind.” In their latest sargassum bulletin, Hu and his colleagues also stressed that the sargassum belt isn’t one giant blob of uninterrupted seaweed, but rather a collection of “clumps and mats scattered randomly within the 5,000-mile Sargassum belt.” Within the belt, seaweed covers less than 0.1% of the ocean surface, on average. Because it’s so scattered, it can be hard to pinpoint how big the sargassum bloom is; for instance, the researchers said that their February estimate was low because of “persistent cloud cover in the eastern Atlantic” that blocked their satellites’ view of the sea.


Source: miamiherald.com 04/04/2023

Tides of trouble: what asthmatics & everyone should know about the risks from sargassum (seaweed) along the coastline


You’ve probably already read the ominous media reports of the coming wave of the largest Atlantic sargassum belt ever, stretching more the 5,000 miles and circling the Gulf of Mexico and mid-Atlantic. The largest masses of this class of leafy, rootless and buoyant algae, or seaweed, is expected to wash ashore along Florida’s beaches and elsewhere along the Gulf of Mexico and the Caribbean by mid-summer.

But what about health hazards to people, particularly those with asthma or other respiratory conditions? Not only can such masses of sargassum wreak havoc on nature’s ecosystems, it releases irritants like hydrogen sulfide in the air when it begins to rot about 48 hours after washing onto beaches and coastal communities.

Jose Vazquez, M.D., chief of primary care at Baptist Health Medical Group.

Jose Vazquez, M.D., chief of primary care at Baptist Health Medical Group, has seen patients on occasion with minor flare-ups from contact with sargassum or even red tide, the harmful algal blooms (HABs) that occur anywhere along the nation’s coast, turning parts the water a deep red. Some HABs produce toxins that have harmful effects on people, fish, marine mammals, and birds

“Anybody that has a history of asthma, a history of any chronic respiratory issues, or history of chronic allergies, could be susceptible to large amounts of sargassum because it emits irritants in the form of a foul-smelling gas, called hydrogen sulfide,” explains Dr. Vazquez. “And it could irritate the respiratory tract and irritate your eyes and nasal passages. People that are prone to having those symptoms could be more susceptible.”

Sargassum is a class of large brown seaweed (a type of algae) that floats in island-like masses and never attaches to the seafloor. Large blooms of sargassum are not new to the Caribbean islands, the U.S. coast along the Gulf of Mexico and around Florida’s coastline. Mexico’s Yucatan Peninsula has also seen its share of waves of sargassum in recent years.

Dr. Vazquez urges people who may run across masses of sargassum along the beach to be extremely cautious, and not to allow children to play or touch the piles of seaweed.

“Anybody could be affected if you are exposed to high concentrations, or for a very long period of time,” he said. “Even if you don’t have asthma or if you don’t have chronic allergies, you could also be affected. And you could have some of the same symptoms: coughing, watery eyes, runny nose, maybe even shortness of breath.”

In 2011, the Atlantic Oceanographic & Meteorological Laboratory, part of NOAA (National Oceanic and Atmospheric Administration), noticed that the geographic range of the sargassum belt expanded, and massive amounts began washing ashore along islands throughout the Caribbean Sea. “Although Sargassum provides habitat, food, protection, and breeding grounds for hundreds of diverse marine species, the sudden occurrence of an unprecedented amount of this floating algae can disrupt shipping, tourism, fishing, and coastal ecosystems,” states AOML, which is headquartered in Key Biscayne, Florida.

“We know every year we get a little bit here and there,” explains Dr. Vazquez. “For whatever reason, we’re getting a lot more this year. And, we know that it could have some effects depending on how much accumulates. The sargassum does have some organisms that live in it — little jellyfish, little microscopic organisms, and those could be irritating to the skin if people come in contact with them.”

In more severe cases, especially among clean-up crews and other workers exposed to sargassum-related, airborne irritants.

“High concentration exposure could also affect the nervous system,” said Dr. Vazquez. “You could have headaches and you could have memory problems – although the majority of these recover well. But, there’s been some cases of people that develop long-term neurological effects from this. We’re talking about very high concentrations in closed areas, mostly people that work in industries that produce a lot of hydrogen sulfide, fertilization, plants and places like that.”

Dr. Vazquez has a general “common sense” message to everyone who comes across piles of sargassum or families that are even tempted to play in the masses of seaweed.

“For the public, it’s important for them to use their common sense,” Dr. Vazquez emphasizes. “Don’t overexpose yourself to this, don’t eat it, don’t use it for cooking. Make sure your children don’t eat it. If you have developed symptoms, then step away from it. Use your inhalers if you are asthmatic, and if you don’t get better, see your doctor. This is very treatable. This doesn’t lead to cancer, and it shouldn’t lead to long-term effects. But you should try and avoid exposure to it whenever possible.”


Published: April 4, 2023

Source: baptisthealth.net