A miles-long glob of seaweed is propelling itself toward Florida’s Gulf Coast and is expected to hit the state’s shorelines in the next few days.

Per local outlets, the mass, known as the great Atlantic Sargassum belt, is a 5,000-mile-long glob of seaweed that has been floating harmlessly across the Atlantic Ocean. While at sea, the seaweed served as a breeding ground for fish, crabs and sea turtles.

However, the sargassum will soon be washing afloat on the Gulf of Mexico and in parts of Florida, where scientists say the snarled mass will begin to decay and emit toxic fumes across the region during the summer months. The Sargassum can also potentially block light from reaching coral and negatively impact the water quality as it rots.

The sargassum, which spans twice the width of the continental U.S., will wash ashore as Florida’s Gulf already struggles with an algae bloom, with red tide causing dead fish to wash up on shorelines and cause respiratory issues for beachgoers.

“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.”

“Even if it’s just out in coastal waters, it can block intake valves for things like power plants or desalination plants, marinas can get completely inundated and boats can’t navigate through,” added Brian Barnes, who works for USF’s Optical Oceanography Laboratory. “It can really threaten critical infrastructure.”

USF often tracks sargassum blossoms, and due to climate change, the blanket of seaweed appears to be growing each year due to warming sea temperatures that cause algae to form. 2018 and 2022 had the largest blooms, Barnes said, but this year could potentially top both years.

“Historically, as far back as we have records, sargassum has been a part of the ecosystem, but the scale now is just so much bigger,” Barnes told NBC News. “What we would have thought was a major bloom five years ago is no longer even a blip.”