OCEARCH concluded its return trip to Nova Scotia with the successful tagging and releasing of 11 new white sharks. Along with satellite SPOT-tags, the sharks caught during the expedition were used for sampling purposes as well as given comprehensive health and reproductive assessments.
The sharks can now be tracked in real time using the OCEARCH shark map. The data collected during this expedition will help support 18 individual research projects that includes 32 researchers from 22 institutions.
“Excluding young-of-the-year pups, this is the greatest number of white sharks OCEARCH has tagged on any expedition in the Northwest Atlantic,” said Dr. Harley Newton, Head of Aquatic Health at the Wildlife Conservation Society’s New York Aquarium and Expedition Nova Scotia’s Chief Scientist for the first half of the trip. ”Sample size is critical to all of our research and each sample is invaluable. Nova Scotia has proven to be an important location to advance white shark research and I hope we can return.”
The decision to return to Nova Scotia came after five of the six sharks that were tagged during the 2018 expedition had returned to the area this year, possibly revealing an important aggregation point for the Northwest Atlantic populations.
“We are just starting to expose what we suspect is the tip of the iceberg to a complete white shark universe up here in Canada,” OCEARCH founder Chris Fischer said. “This trip showed us there are sharks of multiple ages from both sexes up here. It’s not just big mature or nearly mature animals, there are also juveniles in this system, lending more evidence to the idea that there’s a whole sub-population of Northwest Atlantic white sharks here in Canada.”
Among the highlights of the expedition included the first-ever ultrasound imaging of a pregnant white shark, revealing the heartbeat of its pups. The recordings found that shark pups have a heart beat of roughly 10 beats per minute while in utero.
Another interesting development was Vimy, a 12-foot, 9-inch, 1,164-pound male great white shark, that was sporting multiple bite wounds from an even bigger shark. Fischer estimated that a shark big enough to leave the wounds found on the Vimy, which was tagged and released unharmed, was at least 15 feet or more and likely resulted from another male during competition from a mate.
“It was clear that something had just grabbed his entire head,” Fischer said.