ENVIRONMENT

Ever since researchers tagged a great white shark nicknamed Lydia off Jacksonville, Florida, a year ago, they’ve been keeping a close eye on her. Their vigilance was rewarded when the 907-kilogram (2,000-pound) fish became the first great white observed to cross the Atlantic Ocean. (National Geographic News)

Use our resources to compare Lydia with other long-distance marine migrators.

Discussion Ideas

• Take a look at “Long-distance Ocean Travels,” our map gallery of different animal migrations in and over the ocean. Which animal’s migration route is most similar to Lydia’s? Do you think the two routes are related?
  • The migration pattern of the Atlantic bluefin tuna is most similar to Lydia’s meandering route.
  • The two fish’s migration patterns may or may not be related. Scientists quoted in the Nat Geo News article say Lydia is probably “following the food” across the Atlantic. And great white sharks definitely eat tuna.

• Go to the Ocearch website’s “Global Shark Tracker.” (It’s so much fun!) Compare Lydia’s migration with other sharks. Where do sharks seem to be most active? Why do you think there isn’t any activity recorded off the coasts of Australia, California, and Hawaii, when we know there have been shark attacks there?
  • Ocearch has tagged many sharks off the entire east coast of the United States and the southern coast of Africa—from South Africa’s Atlantic coast, around the cape, and as far north as Mozambique and Madagascar in the Indian Ocean.
  • As far as why more sharks aren’t recorded in Hawaii, California, or Australia—the map displays only the sharks that Ocearch has tagged and recorded, and there are a lot of fish in the sea! Ocearch just hasn’t tagged many sharks in the Indian and Pacific Oceans. Yet.

• Read through the background information of “Long-distance Ocean Travels.” Compare the tracking methods used for Lydia (described in the Nat Geo News article) and species in the map gallery. What are some of the different ways researchers use to track marine animals safely and efficiently?
  • Watch this awesome video of researchers tagging Lydia in Florida last year. Once she’s herded into an area, they use a hydraulic platform to safely elevate her while a big orange tracking beacon is safely and harmlessly placed on her big beautiful dorsal fin. (Those guys are remarkably sanguine . . . until they’re in the water with that shark.)
  • The Census of Marine Life, the organization that compiled the data used in our map gallery, tracked multiple organisms to document species’ migration routes. “Enrolling some 2,700 researchers from more than 80 countries,” the spotlight says, the census “employed divers, nets, and submersible vehicles, genetic identification, sonars, electronic and acoustic tagging, listening posts, and communicating satellites.”

• Take another look at Lydia’s surprising transatlantic travels. Where do you think she’ll go next? Why?
  • Some researchers think Lydia is pregnant, and have happily speculated where she’ll give birth. Right now, says one scientist, she’s “out in the open ocean gestating her babies . . . [T]his spring, she will lead us to where those baby white sharks are born—the nursery . . . If you forced me to guess” where she’ll give birth “I’d say it was over in the Mediterranean, near Turkey . . . But that’s longball I’m playing. She could turn around right now and head back to Florida.”
    • So, your guess is as good as any expert’s! Is Lydia going to . . .
      • continue to chill out in the Atlantic?
      • head north and spend the spring in Scandinavia?
      • check out the rugged shores of western Ireland?
      • menace surfers off the coast of Cornwall, England?
      • take a Mediterranean vacation?
      • join her cousins in South Africa?