A great white shark’s journey across the Pacific Ocean, from the cold waters of Stewart Island to the tropical seas of Tonga, appeared to have come to an unexpected end when satellite images suggested she had arrived in a remote Canterbury bay.
The Herald has spoken to Canterbury watersports enthusiasts, including surfers and divers, who saw a great white appear on a tracking map and were instantly concerned that such an apex predator had ventured into waters so far north.
But Midge, a great white shark tracked as part of the Great White Project, had never made it there.
Instead, her tracking tag had detached hundreds of kilometres away and floated to a secluded Banks Peninsula spot in a technological twist to an otherwise extraordinary migration story.
Midge, a 2.8-metre female, was initially tagged near Stewart Island and travelled north through the Tasman Sea to Tonga. She lingered there for nine months before making the long return journey south.
She then lost her satellite tag near Stewart Island after completing the migration of more than 3000km.
When the tag detached, exactly as it was designed to do, it began a voyage of its own, drifting north with ocean currents along the Otago and Canterbury coasts.
Where it landed was entirely random: a quiet bay on private farmland near Banks Peninsula, home to livestock in surrounding paddocks.
Dr Riley Elliott, also known as the “Shark Man”, who established the Great White Project for satellite-tagging the sharks, put out a call on social media for anyone in the area who could retrieve it.
He said the distance Midge had navigated was extraordinary.
“She went all the way up north through Norfolk Island, across the Pacific to Tonga.
“Multiple friends of mine who work on the whale-watching boats actually encountered her and several of the other ones we tagged.
“Then she made her way down the Tonga Trench, over the top of New Zealand, down the West Coast by Greymouth, probably hunting tuna, came back along Fiordland and then popped up in Stewart Island.”
Dave Bain, from Christchurch, was one of the pair who recovered the satellite tag from Banks Peninsula after seeing Elliott’s post.
“It was about somewhere between about one and two o’clock in the afternoon when I saw Riley’s post and I thought, ‘Okay, what the hell? Mission, and get the dog out.’”
When he arrived, after navigating road closures in the area, a chance encounter with a local then helped him gain access to the private bay.
“There was a 4x4 coming towards me and I flagged him down to ask for some information.
“It was the dude that I needed to talk to get permission to go down to the bay.”
Bain said the landowner did not generally allow people onto the land, but did so for the scientific purpose of finding Midge’s missing tag.
The owner joined Bain on the search, and they found the tag within five minutes.
But for Elliott, the recovered tag represents far more than a piece of equipment.
It holds valuable information about how the device performed during Midge’s migration, including how it detached, how well its antifouling coating worked, and whether it could be reused.
“It’s a lot of learning you get from it, which [is] invaluable for better deployments going forward.”
The tags gave a glimpse into the life of an animal that many would seldom see.
He said Midge’s data highlighted how certain habitats were ideal for great white sharks, including areas near Motunui Island, off Stewart Island, where the animals aggregate seasonally before their long migrations.
The Great White Project is supported entirely through public sponsorship, allowing people to follow individual sharks in near-real time via the Great White App, with each tag costing $4300.
Michelle Bradshaw, Department of Conservation programme lead for wildlife marking, said the tags contained a “wealth of information”.
“When one is returned to a researcher, they can get a lot of interesting data from it.
“Tags or markings can tell us things like how far an animal moves, who they interact with, how long they live, what their habitat preferences are and so forth.”
She praised those who worked to find the tag.
“It’s a great response from the public.
“Citizen science is an important part of studies that mark wild animals.
“We’re often relying on members of the public to report sightings of marked animals, or help return marks, tags or other trackers that have come off the animals.”
If there are no contact details on a lost animal marker, the public can report sightings or dropped tags to DoC on 0800 ASK DOC.