Wading in seaweed

It's brown and smelly and has blanketed some area beaches.

In recent weeks, the unwelcome seaweed called sargassum has invaded Oak Island, Ocean Isle Beach and Topsail Island, among others.

At Oak Island, a thick layer covers much of the sand, especially near the Ocean Crest Pier.

"I suppose it's sort of a pesky situation, at least," said Dave Cooper, the pier's chief operating officer.

He said fishermen have been complaining about the seaweed, which is also floating close to shore, fouling their lines. Beachgoers try to scrape a patch of sand clear for their umbrellas and coolers - and to stay upwind of the smelly seaweed.

Experts can't predict whether the seaweed mass will diminish, increase or invade other beaches. But here are a few facts they do know.

What is it? Sargassum is a brown algae found in large masses in the Sargasso Sea, a region in the middle of the North Atlantic Ocean, and in tropical waters around the world. It is distinguished by its brown color and small leaves resembling appendages that allow it to float.

What brings it ashore?

Southerly and southeasterly winds break up the seaweed and bring it toward shore via the Gulf Stream current. "It's a natural occurrence," said Michael Durako, professor of biology and marine biology at the University of North Carolina Wilmington. He added sargassum often comes ashore in the summer because winds typically come out of the south in the hot months and the north in the winter. Durako said sargassum comes ashore every year along the East Coast beaches.

Why is it so thick now?

Cooper said in his five years at the Ocean Crest Pier, this is the most seaweed he has seen come ashore. Durako said wind patterns dictate just how much sargassum comes ashore and where it will land.

How long will it stay?

The seaweed dries out and breaks down in the sun and eventually disappears, but how long it's around - and whether it spreads to other beaches - depends on how long the clumps continue to wash up. And that depends on the wind and currents. "It's relatively unpredictable," Durako said.

What is the significance of sargassum?

It may be a nuisance to many on the beach, but sargassum in the water shelters small fish, crabs and shrimp. Durako said fishermen offshore often look for islands of sargassum because game fish are often nearby. He also said the seaweed makes great mulch for gardening. And that also helps get it off the beach.

Shelby Sebens: 755-7963

shelby.sebens@starnewsonline.com