Great white sharks may become more common in Atlantic region waters, experts say

Marine life experts say it is possible that it was a great white shark that attacked a woman in Cape Breton waters on Friday. 

RCMP in Nova Scotia say the 21-year-old woman was airlifted to hospital with serious injuries after being bitten by what is believed to be a shark in waters off Margaree Island.

Maj. Mark Gough, a spokesperson for Maritime Forces Atlantic, said people on scene saw a dorsal fin.

According to Fred Whoriskey, executive director of Dalhousie's Ocean Tracking Network, the wound will have to be examined to determine if it was a shark attack.

He said there are often tooth fragments left behind and a "very characteristic" cut pattern.

"Based on the spacing between the teeth marks and the sizes of the indentation, you can actually begin to link it back to a particular species," Whoriskey said.

He said there hasn't been a shark attack in Canadian waters since 1870.

Shark populations, he said, had been depressed but are recovering. He said blue sharks, spiny dogfish, black dogfish, porbeagle sharks and occasional mako and great white sharks, also simply called white sharks, are now in the Gulf of St. Lawrence. 

Robert Hueter, chief scientist for Ocearch, a U.S.-based shark-tracking organization, said great white sharks have been tracked to the Gulf of St. Lawrence in summer and early fall, although it is not "super common."

He said while there are other shark species in the area, from his knowledge of seal populations in the area, it was "consistent with where a white shark might have been swimming."

"Of the 70 sharks that we have tagged on, on the U.S. and Canadian Atlantic coast, about a half a dozen have ventured up into the northern part of Nova Scotia and around into the Gulf," he said, " And even more have lived along the southeast coast of Nova Scotia."

Hueter said great white sharks prefer cooler waters. With climate change pushing warmer waters further north each year, he said it is possible that more and more great white sharks will be going to the north and into Atlantic Canada.

 A woman was killed in a shark attack in Maine in 2020.

Both scientists said that there are areas that swimmers should avoid if they want to minimize the chances of a shark encounter. 

Whoriskey said he understands that the Cape Breton attack took place fairly close to an offshore island that is a nature reserve and known to be home to seals. 

He said with little human disturbance and an abundance of the food that sharks eat, such areas are best avoided. 

It's an opinion shared by Hueter, who said there are many beautiful beaches in Nova Scotia where people can swim safely. 

"But certainly don't go swimming into an area where there's active seals around you," he said.