A 5,000-Mile-Wide Sargassum Seaweed Blob Is Starting To Wash Ashore In Florida

FLORIDA — For months, scientists and officials have been eyeing a massive 5,000-mile-wide seaweed blob that stretched from the West Africa Coast to the Gulf of Mexico as it made its way toward Florida.

Now, these sargassum blooms are starting to wash ashore in the Sunshine State and the Caribbean, creating a mess that local municipalities are left cleaning up and causing environmental and health-related issues.

Researchers estimate that the blob weighs about 3 million tons, which would be the largest seaweed bloom on record, according to an April 30 report from the University of South Florida's Optical Oceanography Laboratory. This massive seaweed belt has appeared in the Atlantic Ocean since 2011.

The bloom continues to move west, with seaweed buildup seen at beaches in Hispaniola, Jamaica, Puerto Rico and Southeastern Florida.

• Also Read: 5,000-Mile-Wide Seaweed Bloom Threatens FL's Gulf Coast

Pictures shared by The Palm Beach Post show seaweed blooms, often in large quantities, along the coastline in numerous Florida cities, from the Panhandle to the southern tip of the state to the East Coast.

And it’s only going to get worse, the USF report suggests.

“Looking ahead, the total sargassum quantity is expected to increase over the next few months, with impacts of beaching events … worsening,” it reads. “Sargassum aggregations east of the Antilles Islands and in the (Caribbean Sea) will continue to accumulate and migrate westward, while abundance in the (Gulf) will likely increase substantially. Impacts of Sargassum beaching events will continue to be felt throughout the (Caribbean Sea and Gulf) coastal regions, although it is difficult to predict exact timing and location for individual beaching events.”

"It’s incredible," Brian LaPointe, a research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, told NBC in March. "What we’re seeing in the satellite imagery does not bode well for a clean beach year."

The invasive seaweed usually begins to come ashore in South Florida in May, though some Key West beaches started to see signs of the algae in March.

City of Key West staff, contractors and volunteers are raking and clearing Smathers Beach and South Beach daily, according to a video from the city. As the seaweed blooms worsen, the city will also rake Rest Beach and Dog Beach daily. If it’s especially bad, they might even clear the beaches twice a day. (Watch the video below.)

“This large sargassum bloom will likely be affecting much of coastal Florida,” according to the video. Here in Key West, we’re poised to meet the issue head-on, our beach-cleaning contractors prepared to rake more than once a day. … Our island relies on our beautiful water and the tourism it draws to our community.”

While the algae drift serves as an ecosystem for marine life and is home to more than 100 species, it creates problems when it comes ashore.

These blooms threaten coral reef systems by blocking sunlight and choking coral. It also interferes with sea turtle nests and causes massive fish kills.

As it builds up on shore, the seaweed rots, producing a hydrogen sulfide gas that smells like rotten eggs, according to the Florida Department of Health. This can cause respiratory issues for those exposed to the smell, especially people with asthma and other health problems.

It also has a negative effect on tourism, often keeping visitors away. A 2020 study showed that 1 in 10 tourists said they’d reschedule a vacation to Key West if they knew the sargassum bloom was present, according to NPR. This accounts for a loss of $20 million to the city’s economy and about 300 jobs.

Watch a video from the city of Key West about the sargassum blooms washing ashore: