TAMPA, Fla. (WFLA) — Marine scientists are tracking a 5,000-mile-wide seaweed bloom that is so large, it can be seen from space.

These sargassum blooms are nothing new, but scientists say this one could be the largest in history. At last check, it was heading toward Florida’s Gulf Coast.

The thick mat of algae drifts between the Atlantic coast of Africa and the Gulf of Mexico, providing habitat for marine life and absorbing carbon dioxide, but it can also wreak havoc when it gets closer to shore. It blocks light from reaching coral and negatively impacts air and water quality as it decomposes.

Florida’s Gulf Coast is already grappling with an algae bloom amid the busy spring break tourism season. Red tide has caused dead fish to wash ashore in droves, while the risk of respiratory irritation for humans has canceled events and driven beachgoers away.

Fouad Belrhazi said he came to Florida for fishing and swimming, but was surprised by the conditions he found.

“I was coughing so bad,” he said.

With a blanket of sargassum approaching, spanning twice the width of the continental U.S., scientists warn that Florida beaches could soon be inundated with seaweed.

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

LaPointe, who has studied the blooms for decades, said beaches in the Florida Keys are already being affected. Earlier this week, parts of Mexico were told to prepare for up to three feet of sargassum to build up on shore.

Chunks of brown plant matter may be unappealing to look at, but the impact on humans does not end there. Large pieces of sargassum can ensnare boats and other machinery in the water.

“The problem comes when it comes to shore,” Brian Barnes, a professor at the University of South Florida College of Marine Science, told NewsNation. “It can come up on the beach, in which case it starts to decompose and really smell, and some of that decomposing stuff can leak back into the water and cause water quality problems.”

Scientists have found that climate change is causing ocean temperatures to rise, creating a more ideal environment for the algae to thrive. Meanwhile, urban and agricultural runoff is sending nitrates from fertilizers and other nutrients flowing into the ocean, feeding the bloom.

Typically, rafts of sargassum gather in the Sargassum Sea region in the northern Atlantic Ocean. From there, the Gulf Stream pushes the algae around the Atlantic basin, which allows it to spread and grow in different areas.

NewsNation reporter Xavier Walton and The Associated Press contributed to this story.