Just outside the Tryon River on Prince Edward Island, Brian Campbell’s boat motor began to stall as it became surrounded by lion’s mane jellyfish.
“I’ve never seen that many before,” said Campbell. “They would get caught up in that propeller. There’s quite a few of them — I want to say thousands and thousands.”
Lion’s mane jellyfish can grow to two metres in diameter with tentacles as long as 30 metres, roughly the same length as a blue whale.
What’s more? They sting.
High concentration of lion’s mane
“Wouldn’t want to be swimming there that day, that’s for sure,” said Campbell, who has been a fisherman for 42 years.
“It’s all right if you got one or two that sting you. But at that point right there, I think you could probably do some harm … if you get 30 or 40 on you.”
Last Tuesday, Campbell posted on Facebook warning people not to swim in the area. He later added a video of the encounter.
Oceanographer Nick Record says the species is common throughout Atlantic Canada and the Gulf of Maine, but this is the first he’s heard of such a large group.
“I’m pretty sure that’s the highest concentration of lion’s mane jellyfish that anyone has reported to me,” said Record, a senior research scientist at the Bigelow Laboratory for Ocean Sciences, a non-profit research institution in Maine.
Record said he has noticed a new phenomenon of gigantic lion’s mane jellyfish washing up onshore.
“They’re usually about the size of a dinner plate or smaller,” he said. “The last 18 months or so there’s been a handful, maybe five to 10 instances, where they were like [one and a half to two metres] across — so just giants.”
Record has been using citizen reports to track the creatures for about a decade. He said it’s hard to know whether or not jellyfish are increasing based on the reports, because while more reported sightings could mean more jellyfish, it could also just mean more people are out on the water.
That being said, there are several factors that could impact the population including weather, currents and the food chain.
“Partly it’s the biology. Jellyfish can reproduce really quickly when conditions are good,” said Record. “Partly it’s the ocean physics.”
‘I couldn’t believe how many there was’
“When I first saw it, I thought maybe somebody hit a seal up there just a little ways away,” said Chad Gallant, a lobster fisherman in North Rustico, P.E.I.
“There was a bunch of pink in the water. I thought it might’ve been blood.”
It wasn’t blood, it was jellyfish.
These were moon jellyfish, a different species from those Campbell saw.
“We just stopped there,” said Gallant. “I couldn’t believe how many there was.”
Gallant also posted a video on Facebook.
“It’s not too surprising to me to see a really high abundance of them,” said Record. ” But I’ve never seen a photo where they were that dense before.”
Moon jellyfish are seasonal and feed on zooplankton, according to Record. He said they “don’t generally sting,” but some people have sensitivities or allergic reactions to them.
“I thought it was kinda cool,” laughed Gallant. “It don’t bother me from going swimming again.”
Competing with fish for food
Record said there are both pros and cons to seeing groups this large.
“Some people see jellyfish as a total nuisance and large jellyfish aggregations as an unequivocally bad thing,” he said. “Other people see jellyfish as these amazing, beautiful animals and just want to take photos of them all day.”
They can impact the ecosystem in many ways, too. On one hand, they’re prey for sea turtles. On the other, they compete with fish for food.
There’s a scientific debate about whether jellyfish are increasing globally or not.— Nick Record, Bigelow Laboratory for Ocean Sciences
“People have tried to get fish stocks to rebound, but because the [jellyfish] are eating the same food that the fish would be eating, it makes it more difficult for fish stocks to come back,” said Record.
But unlike other living organisms, the jellyfish can survive and thrive in stressed environments with little oxygen and depleted ecosystems.
More data needed
“There’s a scientific debate about whether jellyfish are increasing globally or not,” said Record. “In order to answer the question about whether there’s a long-term trend, you need decades of data.
“We don’t really have that in Atlantic Canada.”
According to Record, this citizen reporting program is “really the only long-term survey for jellyfish in our part of the world.”
In order to track the sea animal, Record has to know where they are. And to know where they are, he needs people to report them. Record said people can send information regarding sightings to [email protected]
There’s little doubt the videos taken around P.E.I. show a significant number of jellyfish. However, whether this means their population is climbing, the response isn’t so clear.
“We don’t know yet,” said Record. “It’ll take many years before we can answer that question.”