For now, smelly seaweed receding from South Florida beaches

Tangled blobs of sargassum on summer sands dissipate during fall

HALLANDALE BEACH, Fla. – The smelly mounds of seaweed that took over much of South Florida's coastline this summer are starting to decrease, but enjoy the beaches now because the tangled blobs will make a comeback.

Sargassum, a product of high nutrients in the water, started to increase, washing up more and more and becoming noticeably overwhelming in 2011. In 2018, the most sargassum ever recorded washed ashore, especially after Hurricane Irma. Much of the brown algae usually drifts around the ocean, accumulating in the North Atlantic, forming the Sargasso Sea. 

Brian Lapointe, an expert on sargassum, who holds a doctorate in biology and is a researcher at Florida Atlantic University, told Local 10's Alex Finnie that  the sargassum shows up on beaches because of a number of factors, and  tropical storms and hurricanes are one of them.

"Tropical storms and hurricanes stir up the seas. The seas get so rough that they literally tear the air bladders off of these floating plants. Since they can no longer float, they go to the bottom of the ocean. There are tons and tons of sargassum down in the abyss, feeding the food chain," Lapointe said. "It's constantly being moved around by way of the coastal currents."

There are combinations that keep the sargassum where it belongs -- in the sea -- such as westerly winds, which blow it away from the beach, but the build up of the blobby seaweed also has to do with the climate's seasonal changes, which allow the seaweed to decline.

September into October is when the levels of sargassum should be at their lowest. Don't expect it to stay that way; experts say the levels are expected to rise again.

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