Sightings of Portuguese Man o’ War trigger warning for North Carolina beach

Sightings of Portuguese man o’ war off Oak Island in North Carolina prompted a purple flag warning on Sunday and into the July 4 holiday week, with authorities urging beachgoers to exercise caution.

A purple flag indicates dangerous marine life in the water and advises visitors to be careful when swimming.

The Portuguese man o’ war is closely related to the jellyfish and belongs to the genus Siphonophores. Its tentacles average 30 feet long, but can grow up to 100 feet long, according to NOAA. The Portuguese man o’ war usually swims alone, but can sometimes be found in groups of 1,000 or more.

“The warship resembles an 18th-century Portuguese man-of-war under full sail and is recognizable by its balloon-like buoyancy, which can be blue, purple or pink and extends up to 6 inches above the waterline,” NOAA said.

The sting of a Portuguese man o’ war is rarely fatal, but is described as very painful and usually causes welts on the skin. The Portuguese man o’ war can burn for weeks after it has washed ashore.

If you encounter a Portuguese man o’ war at sea, authorities advise you to leave the area quietly.

“Typically, these animals are removed from the beach within days or even hours due to surf conditions, tides, weather and other wildlife such as crabs and birds,” Oak Island police said.

Oak Island is one of the southernmost beaches in North Carolina, not far from the South Carolina border.

The Purple Flag warning remains in effect until further notice.