Sea butterflies reported recently in surf zone along Bogue Banks

An Emerald Isle beachgoer points a finger at the tiny, needle-like shards of sea butterfly shells recently. Last week, the town flew purple flags on the beach to warn swimmers of the hazard. (Contributed photo)

EMERALD ISLE — Purple flags flew on Emerald Isle beaches last week, warning oceangoers of the presence in the water of sea butterflies, an organism related to snails, but capable of inflicting painful though generally harmless “stings” from their sharp bodies.

Emerald Isle Ocean Rescue Coordinator Capt. Bill Matthias, of the town fire department, said the lack of currents and the absence of normal southwest winds allowed them to wash in.

“It’s not just Emerald Isle,” he said Wednesday. “They’re being reported pretty much up and down Bogue Banks right now, including Atlantic Beach. They’re always out there – when we train in the ocean, which we do every day – you sometimes get them.”

But the conditions recently – very light northerly winds – have brought an unusual number of the “flies” floating into the surf zone, where people swim and play. Southwest winds, normal in summer, usually keep them from becoming a problem Capt. Matthias said.

“People aren’t worried,” he added. “It’s more of an annoyance, an irritation, than anything. They’re not venomous or toxic.”

They do hurt when they hit you, he said, and can stick and cause temporary skin irritation.

He said he has no idea when the problem will subside.

“It’s Mother Nature,” he said. “We’re doing all we can to educate people.”

What town lifeguards on the beach tell people is to rinse the affected areas with fresh water and change clothes after a swim, because the sea butterflies can stick to clothing, kind of like sand spurs stick to socks or sandals and “bite” your feet when you put them on or take them off.

“It’s definitely not dangerous, but it is annoying,” Capt. Matthias said. It can, he said, feel a bit like touching fiberglass.

He suggested people who are concerned about the sticky, needle-like prick might want to delay getting into the ocean until right before they leave the beach.

Although they are nettlesome, sea butterflies, which contrary to their name, don’t have wings and can’t fly, are not toxic. According to a 2013 article in Smithsonian magazine, the creatures – a member of the species pteropod – “use their muscular foot to swim in the water instead of creep along a surface” like snails. They float and swim freely in the water and are carried along with the currents.

They are difficult to observe, according to the article, since the shell is mostly colorless, fragile and usually less than 0.4-inch long. The shells are made of calcium and can be like shaped like needles. The “flies” feed on plankton, can swim in very large groups and are found from the tropics to the polar regions.


Contact Brad Rich at 252-864-1532; email; or follow on Twitter @brichccnt.

(1) comment

Mr. Tom Slick

Well, has they say, there is a first time for everything. I have lived in CC for my whole life and all my ancestors and I have never heard of such. Oh well take care and be careful out there...…………...God Bless...

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