Winds bring abundance of Portuguese man o' wars to beaches

More than 40 treated for stings at Duval, St. Johns beaches over weekend

JACKSONVILLE, Fla. – Portuguese man o' wars are always floating in the open Atlantic waters, but sometimes they make an appearance on the beach when waves and winds push the free-riding man o’ wars into the swim zone. 

They started showing up earlier in April around St. Augustine Beach and have increased up the coast into Duval County.

Jacksonville Beach lifeguards said 20-25 people were treated for man o' war stings Sunday, and three had been treated as of Monday afternoon. 

St. Johns County Fire Rescue officials reported they had about 20 stings over the weekend, including one person who had to go to a hospital. 

With the Gulf Stream about a mile off the coast in South Florida, they can be a common occurrence down there, but the drifting animals typically stay off the coast in North Florida. 

Portuguese man o' wars are like a sailboat. Their middle round part is filled with gas, which acts like a sail of a sailboat, floating along with the wind and recently being pulled on shore with onshore winds. 

Though the winds have died down a bit, there are still ocean currents, which could continue to bring them onto the beach in the coming days. 

Judy Petrek, who's from Virginia and has been vacationing in Jacksonville, told News4Jax on Monday she and her son, Anthony, have seen plenty of man o' wars during their trip.

"We've been walking up and down the beach every day, and they're everywhere," Petrek said. "We went up to the lifeguard towers and asked them what the different flags meant, and they told us the purple meant there's dangerous animals in the water."

The stealthy drifters are hard to spot in the ocean. At most, the tops float about 6 inches out of the water. Their bluish color blends into the ocean to help the animal avoid predators. 

Swimmers should be careful if they see one in the water. The stinging tentacles can extend 30 feet from the floating, balloon-like bell and typically trail into the direction the wind is blowing from. Some have been know to extend 100 feet away.

Those that wash ashore can still sting a beachcomber weeks after laying in the sand, and their stinging cells can cause skin welts and rashes. The sting from a man o' war has been compared to a bee sting.

If stung, the best treatment is to immediately inactivate the sting with generous amounts of mild vinegar. Use tweezers or a rag to remove tentacles and wash with seawater or sterile saline. Try not to use fresh water or rub the affected area.

Monitor for allergic reaction. Some people may swell up and get fatigued. Shock is rare but possible. However, most stings go away on their own in a couple of hours.

They pack a painful punch because venom is delivered by coiled, barbed, microscopic harpoons called nematocysts.

The Portuguese man o' war feeds by paralyzing and killing small fish and crustaceans.

It is not a true jellyfish, but a group of animals that are closely related to jellyfish. Each part of the animal colony has a specialized task to reproduce, eat, float and all work together as one.

What's remarkable about this organism's success is that it hasn't changed much in 600 million years, and they sometimes float in groups of 1,000 or more.


About the Authors:

After covering the weather from every corner of Florida and doing marine research in the Gulf, Mark Collins settled in Jacksonville to forecast weather for The First Coast.