Gulf Coast residents have entered their third month of dealing with a smelly, spongy, slimy scourge.

Sargassum, a free-floating type of seaweed, has washed up day after day on beaches from the Florida Keys to Galveston, Texas, since early May. The seaweed, in some places several feet high, is overburdening local cleanup crews, some say dissuading tourists from visiting, and confounding researchers who say they haven’t seen such a seaweed surge in decades.

“It lands on the Texas beaches every year, but this year is by far the heaviest that I’ve seen,” said Texas A&M researcher and sargassum expert Robert Webster, who has lived in the Galveston area since the 1960s.

While all of the Gulf of Mexico seems to be experiencing a larger seaweed influx than usual, Galveston seems to have it particularly bad, with deposits accumulating several feet high for miles. Seaweed cleaning crews are running out of space to pile the stuff, and the city’s annual $2.5 million seaweed budget is running dry.

“When it lands on the beach it immediately dies, and the marine species that use it as protection and a food source expire also,” Webster said. “Then the birds come in and feed on the species. And it goes through these phases — first you smell the dead marine species, and then you start smelling the decomposition of the sargassum itself.”

No one is sure what’s causing the huge increase. The Texas coast is “like a nursery for sargassum,” according to Webster. But most years the sargassum isn’t this active, and while there are bigger blooms every few years, this one seems to be particularly huge.

Sargassum grows in a specific part of the Atlantic Ocean called the Sargasso Sea and grows larger as it slowly drifts to the Gulf. Webster theorized that a recent spate of cold fronts gave the seaweed ideal growing conditions this year. That, coupled with some unusual currents, could explain why so much seems to be washing up.

Global warming has been shown to affect seaweed to varying degrees, causing it to bloom bigger in some areas and shrink in others, but it’s not clear what impact, if any, global warming had on the sargassum that’s ended up in the Gulf.

Environmental groups are worried that turtles will be unable to lay eggs on the beaches affected by sargassum, and that the ones that are laid will be suffocated or crushed by the thick layer of seaweed.

And officials fear the cost to the city’s tourism industry.

“We're not impressed with the seaweed,” Juli Craft, a tourist visiting Galveston from Lexington, Ohio, told the Houston Chronicle. “It's kind of nasty.”

Still, Craft said she plans on returning to Galveston regardless of the sargassum.