How a great white shark altered an N.S. underwater researcher's diving plans for 2022

An ocean can be seen in this undated image. (Blaque X from Pexels)

HALIFAX -

Chris Harvey-Clark says a close underwater encounter earlier this year with one of the ocean's great predators has changed his diving plans for 2022.

On Nov. 9, as Dalhousie University's veterinarian was scuba diving in waters off Halifax, hoping to see torpedo rays, he was hunted by a great white shark 23 metres below the surface.

In an interview Friday, the diver recalled how the juvenile shark's length of two to three metres indicated the animal was at its most dangerous stage of development -- when it stops focusing on hunting fish and starts seeking large mammals. Rather than being intimidated by the bubbles, noise and lights of the underwater human, the shark seemed curious and appeared to go into stalking mode, the researcher said.

"These days we don't have the opportunity much to be hunted by large predators, but I can tell you large parts of your brain light right up when you're on the receiving end," he said. The animal cruised by him three times, he said, adding that it was a clear sign of its interest in him as prey.

Harvey-Clark said the experience changed his approach to diving at the site.

"My willingness to get in the water in that area from August to November is going to go way down," said Harvey-Clark, who teaches a summer course on sharks at Dalhousie.

The waters of the coastal Atlantic are warming, and researchers are reporting more shark sightings. Harvey-Clark suggests it's reaching a point where it's wise for frequent divers and students of the ocean to consider the risks and be aware of their presence.

The North Atlantic tends to be murky and dark -- superb hunting conditions for ambush predators to hunt seals, he explained. "The great whites can discern very subtle shades of grey that you and I can't see, which means they can see you and you can't see them in poor visibility."

He recalled ascending quickly to the surface, but he said that as he came close to the boat, he felt a deep, instinctual terror that humans experience when they sense they are being preyed upon.

"It was really scary," he said. "I was just waiting for that searing crunch and having some body part carried away."

Next year, he said he'll use remote sensing systems at times instead of dives to study torpedo rays, particularly in the summer.

Harvey-Clark, who provides submissions to the Florida-based International Shark Attack File, noted that 2021 was also the year of a suspected shark attack involving a 21-year-old woman from Cape Breton. She was allegedly bitten off the west coast of Cape Breton in late August.

He said he requested an interview with the woman to file a report on the attack, but he heard through his contacts she had declined to be interviewed and as a result, there are no definitive findings on what happened.

"I understand her concern, just seeing one (shark) scared the heck out of me," he said. "This was the most terrifying event in my life."

Harvey-Clark said that while working on a documentary recently about great white sharks, he was amazed at how close the animals were to the Nova Scotia shore. "They are right there, 30 metres offshore in six metres of water," he said.

Sightings of great white sharks have increased in recent years. For example, this past summer, tourists on a whale-watching boat off Cape Breton captured video of the predator ripping at a seal carcass.

Fred Whoriskey, executive director of the Ocean Tracking Network at Dalhousie and Harvey-Clark's research partner, has said there isn't scientific consensus on whether the great white population is increasing in the northwest Atlantic. But he has said there are tentative signs that more of the animals are coming into the region, such as increased sightings of young sharks by scientists and the public.

The species is listed as endangered in both Canada and the United States -- meaning harvesting the animals is prohibited -- and Whoriskey has said the restrictions have likely helped the population of great whites recover in recent decades.

This report by The Canadian Press was first published Dec. 24, 2021.