Most of those sharks haven't stuck around in Canada though. The water's getting too cold for them. So like snowbirds on Interstate 95, they're migrating down south for the winter.
"Almost all of them, if they haven't made their way down here, have at least started to," said Bryan Franks, a shark expert at Jacksonville University, a partner with Ocearch.
Some of the Canadian white sharks are around the Carolinas.
Sydney, a 1,124-pound male, surfaced near Daytona Beach on Nov. 6. Some have already gone around the Keys and into the Gulf of Mexico.
A couple of laggards are still toughing it out in cold water near where they were tagged, but Franks is sure they'll soon head south as the others did.
Ocearch's scientists put GPS tags on the sharks that ping on a satellite when the shark surfaces, giving a fix on its location. In recent years that evidence has helped confirm the migratory patterns of white sharks: mostly to the north, to Massachusetts and Canada, in the summer, then south for the winter.
"It does seem to be clear now that the Southeastern United States is their winter habitat," said Franks.
The southbound sharks tagged and then released in Canada have already been making news.
Unama'ki got some notoriety for her gigantic size: She measured at 15 feet and 5 inches, and weighed in at 2,076 pounds. Since she was caught off northern Nova Scotia on Sept. 20, she's traveled around Key West and into the Gulf of Mexico.
Vimy, almost 13 feet long, got a lot of press because of two giant bite marks on his head, one of them pretty fresh. Scientists figured he must have been attacked by an even larger shark. Vimy recently pinged well off Wilmington, N.C., heading south.
Ocearch is a shark advocacy group that in 2017 partnered with Jacksonville University. As part of the agreement, JU added a shark expert of its own - Franks, an assistant professor who specializes in shark biology and ecology.
He was on the Nova Scotia expedition for about a week. Christina LoBuglio, a JU graduate student who is Ocearch's program coordinator, was on board from Sept. 12 to Oct. 8
She was on the science team that gathered evidence from the caught sharks before they were released. That including gathering sperm samples from male white sharks (it involves a catheter and, one imagines, some steely nerves) and fecal samples as well (they like to eat seals).
Scientists were able to get the heartbeat of a great white for the first time with an ultrasound - 10 beats per minutes.
"That we were able to catch those 11 sharks, going back next year we can expand that even more to learn more about these populations, why Canada is so important," LoBuglio said.
Rebounding seal populations in Massachusetts and Nova Scotia, the result of protections given the species, has led to more sharks looking to feed. That's resulted in more sharks in the northwest Atlantic in recent years, after what Franks calls a "pretty serious decline" in the late 20th century.
And that's a good thing.
"They help to create a stable ecosystem," said Franks. "What we've found is that when top predators, like white sharks, are removed from the system, it tends to destablize the system, things just tend to go haywire and out of whack. They help maintain that balance."
The Nova Scotia expedition had help from JU aviation professor Ross Stephenson, who took two aviation students and a marine science student on the expedition. They flew drones that were able to spot seal colonies, which is why Ocearch fishing teams were able to target where to fish.
The Ocearch research vessel, a 125-foot steel-hulled vessel that once plied the Alaskan fishing grounds, is now in Brunswick, Ga. Preparations are being made to make Mayport its home base, something Franks expects to see in about two years.
In the winter of 2013, the Ocearch crew caught and tagged Lydia, a 14 1/2-foot great white, within sight of the Poles at Hanna Park, one of the area's most popular surfing spots.
That was a few weeks after an even bigger great white - Mary Lee, a 16-foot, 3,500-pound giant - was tracked by its satellite tag into the surf zone in Jacksonville Beach on a cold January night.
White sharks are popular figures of fear and fascination, from "Jaws" to various TV shark weeks. But the International Shark Attack File in Gainesville notes that no one in Florida has yet been attacked by a great white.
Still, Mary Lee made headlines with that close encounter at the Beaches, and Lydia got some alarming headlines of her own when she took an unusual path into the Eastern Atlantic, leading the British press to note that swimmers there could become "easy pickings" for the "hungry creature."
The batteries on the tags of those two sharks have died, so Ocearch is no longer tracking them. But the group has tagged more than 20 new white sharks in the past year.
"With science, you learn more, and then have to ask more," said Franks.
To be sure, there's still a lot about the solitary sharks to learn, he said: "But were getting there."
Information from: The (Jacksonville) Florida Times-Union, http://www.jacksonville.com
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