TORONTO -- In Atlantic Canada, people are noticing a new wave of visitors -- though not the usual two-legged variety.

Sightings of great white sharks and other large sharks appear to be on the rise, with videos of these top predators popping up all along the U.S. eastern seaboard up into the Maritimes.

In one video, posted Monday by the Massachusetts State Police Air Wing, there is no mistaking them.

Swimming through crystal-clear turquoise waters, just forty-five metres off shore at Newcomb Hollow Beach: two great white sharks, captured on film by the helicopter above.

Last week, a sixty-three year old woman was killed by a shark while swimming just off the coast of Maine.

Over the long weekend, more than a dozen were spotted along the upper reaches of the U.S. eastern seaboard, prompting closures and warnings to beach goers.

In Atlantic Canada, Lobster fisherman Justin MacDonald had an interesting encounter with a great white at the start of August, when he was on his fishing boat in the Bay of Fundy.

"One of the guys working with me says, ‘Hey, there's a shark in front of us,’” MacDonald told CTV News. “We just kind of brushed him off and we just kept working. And then we noticed that the fin was swimming around, so it was like: ‘Oh, it's actually a shark.’"

Video they captured of the potential shark in the water wasn’t conclusive, but their suspicions were satisfied when they started pulling up buoys with a distinctive look to them.

“We noticed a whole bunch of shark teeth in the buoy,” MacDonald said.

He posted photos of the chomped-on buoys to his family business’ Facebook page, showing how many shark teeth had become embedded in the buoy as a result.

One photo showed a tooth sat on top of a Gatorade lid, to demonstrate its size—the tooth was almost as long as the lid.

When one thinks of great white sharks, Canada’s cold waters aren’t usually the first location that springs to mind. Generally, they are found more often in temperate or tropical waters.

Under Canada’s federal Species at Risk Act (SARA), the white shark is listed as “endangered” in the Atlantic Ocean -- a designation that hasn’t been updated since 2006.

Although shark sightings so close to the shore are unusual, finding these top predators in Canadian water is becoming more and more common.

New research published in July in the Canadian Journal of Fisheries and Aquatic Sciences tracked the level of great white sharks in Atlantic Canada, and found that “white sharks are a more common and consistent occurrence in Canadian waters than previously thought.”

Although “great white shark” is the popular term, scientists generally refer to these huge creatures as simply white sharks.

The authors, including researchers from the University of Windsor, suggest that either increased tagging of sharks is simply revealing a greater historical shark presence than we were aware of before, or great white sharks have begun expanding northward in larger numbers, “potentially due to climate change, population recovery,” or to follow prey.

“The prevailing perspective that white sharks are rare seasonal visitors to Atlantic Canada waters is based on historically infrequent sightings,” the study stated.

From 1872 to 2016, there were 60 recorded observations of white sharks in Atlantic Canada, according to the study, and sighting data from 2008 onwards showed an increase in the occurrence of the sharks.

But sightings themselves are not the full story.

Using data from sharks tagged by the U.S.-based OCEARCH program, the researchers were able to track the movements of 18 sharks tagged in U.S. waters between 2013 and 2019. Of the eighteen, 50 per cent swam up to spend some time in Canadian waters.

In the past few years, several OCEARCH expeditions in Canada have also tagged sharks off of Nova Scotia, tagging six great white sharks in 2018 over 17 days of dedicated fishing, and then 11 great white sharks in 2019 within 19 days of fishing.

All six sharks tagged in 2018 returned to the area the next year.

OCEARCH keeps track of their tagged sharks on their website, where an interactive map displays the current location of each tagged marine animal—meaning you can watch sharks given monikers such as Betsy, Jane and Vimy swim around the region throughout the summer.

As of Sunday, around eight white sharks are visible hanging around Atlantic Canada on OCEARCH’s map. And that’s just the ones that are tagged.

A family in Nova Scotia had a close encounter with a great white shark in late July, when they saw an untagged shark swimming alongside their speedboat near Wedgeport.

They nicknamed the shark “Giganto.”

The full picture on why there might be more white sharks in Canadian waters is still not fully known, but researchers say it’s something that needs to be looked into, particularly if there is a chance of more human contact with sharks.

“Whether the consistent seasonal presence of white sharks in Canadian waters had previously gone unknown or is a result of population recovery, a northward shift related to increasing ocean temperatures, and/or increased abundance of marine mammal prey requires further investigation,” the study states in its conclusion.

Regardless of the reason behind the increase, these sightings definitely show that even in our cold waters, these enormous sharks are perfectly comfortable.

With files from Kate Walker and Leigha Farnell