Dr. Beach sounds the alarm: Florida to be swarmed by a 5,000-mile-long belt of seaweed

Ana Cedeno | Staff Writer

Known as Doctor Beach, Earth and Environment professor Stephen Leatherman has received national coverage over his annual beach rankings. 

Recently, this passion has also made him the bearer of bad news, as he’s sounding the alarm to a 5,000-mile-long belt of seaweed threatening to cascade the state’s beaches. 

“I study beaches and rate them for their quality, and sargassum is definitely impacting the quality of beaches,” said Leatherman.

A species of brown seaweed common to the Atlantic Ocean, sargassum lives its entire life floating on the surface of the sea. It usually serves marine life.

“It forms a habitat in the open ocean of hard substrate and three-dimensional habitat that’s unavailable out in the open ocean,” said Thomas Frankovich, research associate professor for FIU’s Southeast Environment Research Center.

“So rafts of those are islands of productivity, not just the algae themselves, but they’ll harbor their own life, and there are life forms that are specifically adapted to living with sargassum,”  said Leatherman, adding that there were organisms such as shrimp species, juvenile fish and even sea turtles that rely on these sargassum rafts. 

However, scientists have noticed an increase that could threaten local ecosystems. 

 “Sargassum has always been a factor I look at,” said Leatherman, referring to his beach rankings. 

“2018 was the worst year that we had, but this year looks like it’s gonna be the worst ever and the bulk of it is gonna be arriving in July and August.”

Frankovich would concur, highlighting the detrimental effects Sargassum beaching can have on beach quality. 

“It’s mostly a problem with when it piles up on the beaches,” said Frankovich, explaining that once the sargassum hits the shoreline it starts to decay, acting as a hub for harmful bacteria. 

“There are already beaches that have three to four-feet-high mounds of this rotting sargassum.”

 According to Leatherman, these mounds of rotting seaweed are the direct result of pollution.  

He explained that deforestation of the Amazon and industrial agriculture runoff stemming from the Orinoco River have led to an overabundance of nutrients. 

“Both rivers blow out to where the sargassum is in the oceanic current,” said Letterman. “It causes the population to explode.”

Speaking to the complexity of the issue, yet another factor in this growth has been the nutrient-carrying dust clouds stemming from the Sahara Desert.

“There’s also a lot of burning going on just south of the Sahara desert,” said Leatherman. “The wind’s picking up that material too, and it contains nitrates and phosphates, the two major nutrients for fertilizer so that’s definitely contributing too.”

Leatherman was also keen to highlight the challenges researchers and policymakers face in attempting to abet the explosion of sargassum.

“There isn’t a simple solution,” said Leatherman. 

“There are several people here at FIU that are working on this, first you have to understand what’s happening, we’re at that stage, but I don’t know if they can do enough to put a dent in the mountain that’s coming”