‘Alien’ Portuguese Man O’ War Becoming More Common Off Nova Scotia Coast

‘Alien’ Portuguese Man O’ War Becoming More Common Off Nova Scotia Coast
‘Alien’ Portuguese Man O’ War Becoming More Common Off Nova Scotia Coast

HALIFAX — With a little help from the warming Gulf Stream, beachgoers in Nova Scotia are facing a strange creature with a balloon-like body whose sting is stronger than that of a jellyfish.

Last week, a Portuguese man o’ war appeared at a surfing hotspot at Lawrencetown Beach in Dartmouth, N.S. The creature, a type of siphonophore — closely related to jellyfish — has a transparent, inflated sail often decorated with purple, blue or pink markings. It drifts through the water, propelled by currents and wind.

While there are no concrete figures on how often the Portuguese man o’ war is spotted in Nova Scotia, Sandra Johnston of the province’s Natural Resources Department says sightings have become more frequent along the east and south coast beaches since 2020.

“(Getting stung) is a pretty painful sting. It’s like a jellyfish sting, but much stronger and lasts about 20 minutes,” Johnston said in an interview.

Boris Worm, a biology professor at Dalhousie University in Halifax who researches marine conservation and biodiversity, called the subtropical creature “absolutely fascinating and otherworldly.”

According to Worm, the increase in the number of Portuguese man o’ war in Nova Scotia is likely because the Gulf Stream, a channel of warm water that flows along the east coast of North America, has strengthened in the northwestern Atlantic Ocean, warming Nova Scotia’s south coast faster than other parts of the ocean.

The Portuguese man o’ war live in subtropical gyres — swirling bodies of water that have become home to a wide variety of organisms. As the influence of the Gulf Stream grows stronger, tropical and subtropical creatures are transported farther afield, all the way to the coast of Nova Scotia.

While other jellyfish species tend to live in deeper water, the Portuguese man o’ war floats closer to the surface. Its tentacles typically extend several meters behind it — in extreme cases they can be up to 30 meters long — and Worm said their length increases the risk of contact with swimmers.

“You could swim without ever seeing the sail or the organisms that are 10, 20, or 50 feet away, but the tentacles could still come after you and sting you,” Worm said.

Other tropical fish found in Nova Scotia due to warming waters include butterflyfish, triggerfish and seahorses.

Neither Nova Scotia Parks nor the Nova Scotia Lifeguard Society keeps track of Portuguese man o’ war; Nova Scotia Parks said it issues online and on-site alerts when the creature is spotted. Nova Scotia Health said hospital visits are not tracked by cause, so there’s no way to know how many people seek help for Portuguese man o’ war each year.

Jill Duncan of the Atlantic Canada Poison Centre said the low risk of serious injury from these stings further obscures the number of people stung each year. “The most common thing that happens when you get stung is pain and red bumps where you’re stung,” Duncan said in an interview.

“It is unusual to go to the hospital and even more unusual for serious consequences and death to occur.”

Contrary to old wives’ tales that urine is an effective antidote to a jellyfish sting, Duncan said the best treatment after contact with a Portuguese man o’ war is to rinse the wound with salt water and then immerse it in warm water.

This report by The Canadian Press was first published July 8, 2024.

Cassidy McMackon, The Canadian Press