Giant blob of seaweed twice the width of US taking aim at Florida, scientists say

Rafts of brown seaweed, Sargassum sp., pile up on the shore of Miami Beach, Florida, USA. (Photo by: Andre Seale/VW PICS/Universal Images Group via Getty Images)

A giant seaweed bloom – so large it can be seen from outer space – may be headed towards Florida’s Gulf Coast

The sargassum bloom, at around 5,000 miles wide, is twice the width of the United States and is believed to be the largest in history. 

Drifting between the Atlantic coast of Africa and the Gulf of Mexico, the thick mat of algae can provide a habitat for marine life and absorb carbon dioxide. 

However, the giant bloom can have disastrous consequences as it gets closer to the shore. Coral, for instance, can be deprived of sunlight. As the seaweed decomposes it can release hydrogen sulfide, negatively impact the air and water and causing respiratory problems for people in the surrounding area. 


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

Brian Barnes, an assistant research professor at the University of South Florida’s College of Marine Science, told the outlet that the sargassum can still threaten critical infrastructure if it remains in coast waters. 

"[I]t can block intake valves for things like power plants or desalination plants. Marinas can get completely inundated and boats can’t navigate through," Barnes said. 

The impending seaweed comes as Floridians along the state's southwest coast have complained about burning eyes and breathing problems. Dead fish have washed up on beaches. A beachside festival has been canceled, even though it wasn't scheduled for another month.

Florida's southwest coast experienced a flare-up of the toxic red tide algae this week, setting off concerns that it could continue to stick around for a while. The current bloom started in October.

Red tide, a toxic algae bloom that occurs naturally in the Gulf of Mexico, is worsened by the presence of nutrients such as nitrogen in the water. The Florida Fish and Wildlife Conservation Commission warns people to not swim in or around red tide waters over the possibility of skin irritation, rashes and burning and sore eyes. People with asthma or lung disease should avoid beaches affected by the toxic algae.

The Associated Press contributed to this report.