Sharks are truly cosmopolitan animals, yet we still know little about their great migrations. In a move to unlock some of the secrets of these nomadic lifestyles, a team of scientists, conservationists and professional athletes is setting sail for Japan, marking the first-ever shark-tagging expedition in the area. We're checking in to find out just what the team has discovered in these uncharted waters. 

Image: PangeaSeed/used with permission

The mission has been to find, tag and track sharks as they cruise the Pacific, but it became clear from the start that the task at hand would be challenging. Dr Austin Gallagher of conservation NGO Beneath the Waves turned to big-wave surfer Mark Healey and biologist Dr Yuuki Watanabe for help.

"I have long known about Mark from his accomplishments in the professional surfing world," says Gallagher. "I knew he was an equally impressive free diver who had a good understanding of sharks, so I reached out to him. Mark is easily the best athlete I have ever seen. Our working conditions were often far (and I mean far!) from ideal, so we were lucky to have someone as strong and tough as him in the water every day."

Co-led by Tre’ Packard of Pangeaseed, an NGO that uses art to spread ocean awareness, the team focused on an underwater mountain just three hours off the coast of Tokyo. They knew there were plenty of sharks in the area, but their time in the water involved playing a bit of hide-and-seek with the elusive predators.

"There are likely hundreds to thousands of sharks [here]," says Gallagher. "But it often seemed desolate or barren." It took some waiting, but after countless dives, the crew managed to tag several Galapagos and scalloped hammerhead sharks, the so-called "ghosts of the sea".

Hammerheads are known to live in some of the most dangerous and challenging marine habitats, and their ability to appear en masse, and then disappear without a trace, has earned them the supernatural nickname. 

"They are so unbelievably finicky, shy, and dare I say intelligent," says Gallagher. "It is no surprise hammerheads continue to be a difficult species for scientists to study around the world."

A school of scalloped hammerheads. Image: Pangeaseed/used with permission

Data from the tags, which will pour in over the next six months, will help us better understand how these animals use the surrounding waters – and that's absolutely invaluable to those trying to set up marine protected areas and shark sanctuaries.

"In many cases we don't have this information, so tagging can help address those gaps," says Gallagher. "We aren't just throwing tags into animals for the sake of it, or to get press or boost our egos. We are investing in long-term advancement of knowledge and maintenance of biodiversity on this planet, which is changing so rapidly."

The hope is that the study will not only teach us something about how we interact with these ocean dwellers, but also how they interact with each other. Previous work by collaborator Dr Yannis Papastamatiou suggests Galapagos sharks tend to stick around island chains near Hawaii. "So it will be interesting to see how our results compare and whether they interact socially with hammerheads," says Gallagher, adding that team member Dr. David Jacoby, who has particular expertise in the subject, is extremely excited to see the results. 

What made this expedition so special was the immense amount of cooperation that went into making it happen. The project not only crossed borders, but also affiliations and skill-sets. With nearly a quarter of all pelagic sharks threatened with extinction, we hope to see more like it in the near future.

Check out expedition photos and some of the first "pings" from the sharks below!

The tag, which is placed into a thick muscle on the shark's body, will fall off on its own. It's designed to be as minimally invasive as possible. Image: PangeaSeed/used with permission 
A bit of planning before the dive begins. Image: PangeaSeed/used with permission
Waiting for the right moment. Image: PangeaSeed/used with permission
Image: Pangeaseed/used with permission
A tagged Galapagos shark heads off. Image: Pangeaseed/used with permission
The team also deployed acoustic receivers, which will 'listen' for any sharks passing through. Image: Pangeaseed/used with permission
Image: Pangeaseed/used with permission
Initial data shows the galapagos shark is much more wide-ranging and is doing quite a bit of exploring away from the island itself! The shark appears to be moving north, using an underwater ridge to navigate. 
The hammerhead is much more restricted in her movements - although she did take a nine-day adventure into one of the bays and explored the Japanese coastline before returning to the tagging area. This was likely a foraging mission! 

Special thanks to collaborators: Beneath the Waves, PangeaSeedDr Yuuki Watanabe (The National Institute of Polar Research), Dr David Jacoby (Zoological Society of London), Dr Neil Hammerschlag (University of Miami) and Dr Yannis Papastamatiou (St Andrews).