In the latter decades of the 20th century, great white shark populations in the region were decimated when they were caught as by-catch, that is, accidentally captured while fishing for something else. The shark became a protected species in the mid-1990s.
“The ocean has been out of balance. We destroyed our shark population and overfished other things,” said Bob Hueter, chief scientist with Ocearch in Sarasota, Fla.
“Now we’re starting to bring things back.”
As top predators, sharks help control populations of mid-level predators such as seals.
Chris Harvey-Clark, a Halifax-based shark researcher, diver and veterinarian at Dalhousie University, has been seeing the results of conservation efforts.
“White sharks are not difficult to find at all,” said Harvey-Clark, who has helped film more than 40 underwater documentaries.
In November he went out on an expedition off Nova Scotia’s South Shore, using drones for spotting, and diving cages to capture some underwater shark pictures.
“[We] found it actually incredibly easy to image large numbers of sharks. In one three-day period we got 15 different sharks,” said Harvey-Clark.
Harvey-Clark will be using the pictures he took to develop a tool for identifying individual sharks. Individual sharks can be identified by unique markings on their pelvic fins. Scarring and other markings can also aid in identification.
And Harvey-Clark isn’t the only one spotting sharks off the South Shore. Earlier this month a solo diver saw one in St. Margaret’s Bay.
“The shark came in from deep water, had a look at her, she threw up her arms, and it turned around and hightailed it out of there,” he said.
There was another encounter earlier this week, this time involving a charter boat with a dozen divers in the water.
“They had several encounters with, likely, the same shark,” said Harvey-Clark.
“The shark came by, had a look at them, disappeared out of visibility, and then 20 or 30 seconds later came back for another look and another look.”
While there is need for care, there is not a great deal of need for concern about sharks, said Hueter.
“You have to think like a shark, and you have to remember that the ocean is a wild place, not a swimming pool,” he said.
Sharks are not very interested in people, said Hueter, noting there have been very few encounters leading to injuries in Canada. By thinking like a shark, he means avoiding swimming with their preferred prey, such as seals or shoals of mackerel or herring.
“Birds diving on the surface and fish breaking the surface, that’s not a good place to go swimming,” he said.
There are bigger hazards in the sea than sharks, he said, such as rip currents, or even just the drive to the beach.
Searching for mating grounds
Hueter will be back in Atlantic Canada next week continuing a five-year project tracking great whites along the Atlantic coast.
The original snowbirds, they spend their summers in Atlantic Canada while wintering off the coast of Florida.
“What we’re putting together is the entire life of these sharks from birth to death,” said Hueter.
In 2016, Ocearch confirmed a nursery area for great whites off Long Island, where they were able to tag newborn sharks and track them by satellite as they grew. This is providing valuable information about their summer and winter feeding grounds.
“The last bit is where they’re mating, because as sharks they mate like mammals, they don’t spawn like other fish,” said Hueter.
“We think that that’s happening off the Carolina coast in the late winter early spring.”
Ocearch has a free shark tracking app anyone can use to see the location of the tagged sharks. Users can also submit reports of their own sightings.