FYI.

This story is over 5 years old.

Tech

What We Know About Lydia, the First Great White Shark Tracked Over the Atlantic

Is she headed to Britain? Isn't the water too cold? Is she pregnant?
Image: Flickr/Kqedquest

A shark named Lydia made the history books this week when she became the first great white known to have crossed the mid-Atlantic ridge and effectively traverse the west-east boundary. In the process, she’s caused quite a frenzy in the British press, who are convinced she’s headed their way, and earned herself a substantial social media fan club to cheer her on her way.

You can follow Lydia’s progress using nonprofit Ocearch’s Shark Tracker website. Motherboard’s Lex Berko warned last year that the site could be somewhat addictive for Shark Week nerds, and that’s clearly the case: when I tried to access the website yesterday, it was crashing a lot, presumably due to the hordes of shark fans inspired by Lydia’s epic journey.

Advertisement

Lydia was fitted with a tag in Florida about a year ago, and since then she’s been tootling around the coast before making her break around December and heading across the ocean. She’s now around 1,000 miles off the British coast—but while she could apparently arrive in as little as a few days, she’s still a fair way off and could feasibly end up almost anywhere, from the coasts of Africa to the Mediterranean, or even back home to the US. Her last check-in this morning (the tag only notes her location when she’s close to the surface) shows her continuing on a route bound more northwards than eastwards.

Lydia was tagged last year. Video: Youtube/Ocearch

So what do we know about Lydia? According to Ocearch, she’s around 4.4 metres (14 feet) long and has travelled around 30,500km since she was tagged last March. Chris Fischer, the expedition leader on the shark tagging project, made waves in the shark celebrity press that appears to have popped up in the UK overnight when he told the BBC that he thought Lydia might be pregnant.

That’s all entirely speculation for now—he admitted that other scientists on his team disagree, as blood samples taken when she was tagged didn’t show her to be pregnant. But Fischer developed his theory that Lydia might head to nursery seas in the Mediterranean. “The sperm from the male comes in a packet with a shell on it. They can carry it around for a while until a special organ inside them breaks down the shell and they get pregnant,” he said. They don’t know how long that can take.

Indeed, what Lydia’s travels have revealed more than anything is how little we know about everyone’s favourite aquatic predator. For a start, it may turn out that her apparently remarkable transatlantic trek isn’t that unusual at all; we just haven’t tracked them before. “White sharks may well have been crossing the Atlantic forever, but this is the first time we're actually able to observe it,” marine biologist Gregory Skomal told Radio 5 Live.

General consensus also presumes that the waters around Britain are too cold for great whites, but Ocearch’s research has already cast doubt on that. “One thing we have learnt just in the last year with sharks in the Atlantic is what we used to think was too cold simply is not,” Fischer told the BBC, and added that Lydia had headed over from Nova Scotia in Canada, hardly known for its sunbathing.

In a quote on the Ocearch Facebook page, marine biologist Bob Hueter also points out that this kind of activity emphasises the need for international collaboration on conservation efforts. “Lydia's remarkable trans-ocean journey reminds us that no one locality, state or nation owns these remarkable migrators of the sea,” he said. “If we are to save the sharks, we have an obligation not only to protect them in our waters, but also to work with other countries towards global conservation of sharks.”

At least Lydia’s steering clear of Australia’s misguided shark cull.