South Shore

Long Island Beaches Stink — And the Rotten Egg Stench Is Coming from Seaweed

The seaweed’s blood red color will catch your eye, but the odor can assault your nose

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Something smells pretty bad along a stretch of the Long Island coast, with residents who live near the Great South Bay saying that it smells like rotten eggs or a sewage spill.

The cause of the smell is actually neither of those things. In fact, it's something that a lot of people don't even know is in the water there: red seaweed, and it's relatively new to the area. But it is thriving.

The seaweed’s blood red color will catch your eye, but the odor can assault your nose. Some the red seaweed could be found along the shore in East Islip, and while it may look harmless, those who stopped by to enjoy the view said it can ruin a day at the beach.

"I was parked here one day and next morning, the smell was in my car. That’s how bad it was," said Rocco Panichi, who described it as a dead fish smell.

Dr. Chris Gobler, a marine sciences researcher at Stony Brook University, said the red seaweed was first seen in the Long Island area just three years ago, but is now found in waters stretching across Suffolk County’s South Shore. The invasive species came from Japan likely by boat, according to Gobler, and has only been in North America since 2007.

It can be dangerous, particularly to marine life, and the smell that comes as it rots on shore can also make people sick, as the plant emits hydrogen sulfide gas.

"In some places, people exposed to it have had to go to the emergency room because of inhalation of the toxic gas," Gobler said.

Most concerning of all, Gobler said, is the reason why the red seaweed is flourishing: pollutants in the water.

"It’s growing because it’s using wastewater-derived nitrogen, specifically nitrogen from septic tanks," Gobler said.

It is for that reason that the group Save the Great South Bay said the presence of the red seaweed is an urgent reminder of the immediate need to lower nitrogen levels in local waterways, in order to save the body of water vital to life on Long Island.

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