'Very dangerous' jellyfish found on Harvey Cedars beach

A potentially deadly Portuguese man o' war washed up on the Harvey Cedars beach Sunday and swimmers should avoid them, an expert said.

"They're very, very dangerous, very painful sting," said Paul Bologna, a jellyfish expert and director of Marine Biology and Coastal Sciences Program at Montclair State University. "In some cases, they can be life-threatening."

The Harvey Cedars Beach Patrol posted information about the wash-up on its Facebook page and Twitter Sunday.

"This morning we found a Portuguese man o' war washed up on the beach," the beach patrol said in the Facebook post. "When the wind is coming from the northeast, warm water from the Gulf Stream comes to shore. With the warm water, often comes seaweed & critters from down south. Always be aware of your surroundings in the ocean & always swim near a lifeguard."

A Portuguese man o' war is a floating colony of polyps, each responsible for either floating, collecting food, eating or reproducing, according to the National Oceanic and Atmospheric Administration. The creature has a pink or purple gas-filled float and numerous, long tentacles. The float grows up to 6 inches and the tentacles grow from 10 to 30 feet long.

The jellyfish move by floating on the surface, with the float blown by the wind. Some of them are "right-handed," drifting at a 45 degree angle to the wind. Others are "left-handed," drifting 45 degrees to the left of the wind, according to NOAA. That allows the animals to be dispersed more widely.

Symptoms of man o' war stings include: abdominal pain, changes in pulse, chest pain, collapse, headache, muscle pain and muscle spasms, numbness and weakness, pain in the arms or legs, a raised red spot where stung, runny nose and watery eyes, swallowing difficulty and sweating, according to the National Library of Medicine. Portuguese man o' war stings are rarely deadly, but victims should seek immediate medical attention.

The man o' war follows wash-ups of roughly a half-dozen dangerous box jellyfish in northern Ocean County and a box jelly in the Manasquan River last fall. Experts think the box jellies — extremely rare in New Jersey — may have ridden the Gulf Stream north and a storm or winds may have steered them toward the Jersey Shore. The box jellies could be back this summer, according to experts.

Bologna, who has been studying sea nettles and other jellyfish in Barnegat Bay, said man o' war are fairly common from South America through Florida. He's seen reports of lots of them in Florida earlier this year.

Last year, Bologna did not receive any reports of Portuguese man o' war in New Jersey. They're likely not that unusual here but the Harvey Cedars wash-up "might be a little bit early in the season," he said.

Bologna was unaware of anyone being stung by one in New Jersey. He knows "quite a few people" who have been zapped in the tropics and "most of them report unbelievably painful stings," he said. The stings often lead to scarring, he added.

"People ... need to be aware of their surroundings because these are going to be on the surface," he said. "You should be able to see that (purplish jellyfish) float if you're in the water."

People should leave them alone on beaches because their stinging cells are still active when they wash up, according to Bologna. Beach patrols should be make sure that people who are stung get proper medical attention, he said.

As for the Harvey Cedars jellyfish, "don't mess with that one!" Bologna posted on the new New Jersey Jellyspotters Facebook public group page. "If you are brave, you can put it in a Ziploc with some rubbing alcohol. Use some extra gloves and/or bags to pick up, then a little rubbing alcohol will preserve it and its DNA. Then you can let us know and we will come and get it."

The group is interested in sharing and learning about the jellyfish of New Jersey, according to a Bologna post. Citizen scientists have been trained to help identify and quantify jellyfish and keep an eye out for unusual sightings such as the box jellyfish found in 2014.

More eyes on Barnegat Bay in many different places allows scientists to understand where jellyfish are, where they start blooming and possibly how bad the blooms may be, Bologna said.

Todd B. Bates: 732-643-4237; tbates@gannettnj.com