Shelli Trentcosta was swimming in Lake Pontchartrain near South Shore Harbor on Friday when her 7-year-old son Trent began flailing and unleashed a spine-tingling scream.
“I swam to him, and he was freaking out,” she said in a telephone interview Saturday. “I grabbed his leg, and it was just covered in blood.”
Trentcosta put Trent back onto the sailboat they had borrowed from friends and rushed him to shore, then to an urgent care clinic.
There, a doctor made a startling diagnosis of what had caused the lacerations on Trent’s heel: a shark.
“You could see the rows of teeth,” his mother said.
Trent is recovering from the bite, and his mother said he won’t have any permanent injuries.
The incident is anomalous for Lake Pontchartrain, where shark bites are so rare that many who frequent its waters are unaware the lake hosts a seasonal population of bull sharks.
According to Martin O’Connell, who directs a research laboratory at the Pontchartrain Institute for Environmental Sciences at the University of New Orleans, bull sharks as long as 6 feet congregate in the lake between April and November.
O’Connell looked at pictures of Trent’s foot and agreed the wound most likely came from a bull shark.
“Although it could be a few things, if I was a betting man I would say it was a young bull shark,” he wrote in an email. “The size is about right, you can see evenly spaced wounds, and the wounds look like lines, not holes.”
O’Connell has been studying the bull shark population in the lake for 14 years.
During that time, he has seen a number of researchers get nicked by the feisty sharks as the humans handle them, but he has never before heard of a swimmer in the lake being bitten.
“It’s somewhat surprising,” he said.
According to O’Connell, Lake Pontchartrain may be acting as a nursery for the bull sharks. The specimens he and his team come across are typically young, he said.
Unlike most other sharks, bull sharks can live in water with low salinity.
In fact, said Jonathan Davis, who previously conducted research at UNO alongside O’Connell, young bull sharks appear to prefer water with less salinity, such as the lake.
Bull sharks occasionally swim up the Mississippi River and have been sighted as far north as St. Louis, according to O’Connell.
Though bites in Lake Pontchartrain are extremely rare, bull sharks are known for their aggressive behavior and have been responsible for many attacks off the Florida coast and elsewhere.
A story published in National Geographic in 2002 suggested it was likely a bull shark and not a great white shark that was responsible for four fatal attacks that happened in Matawan, New Jersey, over a two-week span in July 1916.
Three of the attacks happened in Matawan Creek, a shallow tidal river that would have been an unlikely place for a great white to spend time.
Many years later, the attacks served as part of the inspiration for the novel “Jaws,” the basis for the famous 1975 movie thriller with the same name.
O’Connell said the only other shark that’s been sighted in the river is a black-tip shark, but it’s unlikely that it was the culprit.
Davis stressed the uniqueness of the Lake Pontchartrain incident and said it shouldn’t deter people from getting in the water.
“This isn’t a common occurrence, and people shouldn’t be afraid of sharks,” he said.
A 2000 report by the International Shark Attack File at the Florida Museum of Natural History set the odds of being attacked by a shark while swimming in the ocean at 1 in 11.5 million.
Davis added that if a bull shark was responsible for Trent’s wound, it likely was an exploratory bite.
He said the shark probably thought the foot was a fish, and abandoned it once it discovered otherwise.
Trentcosta, a New Orleans native, said Trent is recovering well from the bite, though he’s a bit baffled about why the shark decided to pick on him.
“Yesterday he was a little sad and said, ‘Mom, why did he bite me?’ ” she said.
She told her son it was the muscular legs he’s developed from playing baseball and soccer that must have attracted the shark’s attention.
Trentcosta, who said she’s been swimming in the lake since she was a kid, said she’s still trying to come to terms with the bizarre incident.
“It just freaked me out,” she said.“That was the last thing I would have thought about.”