Massive Great White Shark, Mary Lee, Tracked for Five Years, Goes Silent

Mary Lee when she was first captured and tagged on a research vessel. OCEARCH

In September 2012, researchers put a tracking device on a 3,456-pound great white shark and named her Mary Lee. Now, after five years of tracking, the signal has gone silent. No one has heard from the animal in six months.

Has the 50-year-old shark bit the dust? Probably not, said Chris Fischer, who leads ocean research expeditions and was part of the team that caught and tagged her.

"She's fine," Fischer tweeted. "Just batteries done in her tag. She's been amazing for sharks, science and the future. Now time to let her be." He later said that they might see a response from her tag at a later date, but they might not.

Ocean research organization "OCEARCH" has tagged and tracked dozens of animals around the world, including sharks and sea turtles, with names like "Poseidon," "Vindication," and "Lisha." They take research vessels out to the ocean, capture animals, name them, document them, take samples of blood and parasites, give them fin chips and accelerometers, take biopsies, and do ultrasounds. Then they release the animals after 15 minutes.

Whenever a tagged animal surfaces for long enough, they register a ping on the map, and people can see where they've been. You can also see their travel history on an online map.

According to their website, OCEARCH is a world leader in generating tracking data from marine animals and is currently working on 50 research studies with the data that they're gathering from the worldwide animals. The information could potentially be used to help inform conservation and policy. They even put together some educational materials for schools based on what they've learned about ocean creatures.

Mary Lee was a favorite shark, who was tracked as far north as Cape Cod, as far south as the northern border of Florida, and even to Bermuda. The shark was so popular that she had her own Twitter feed with 129,000 followers. The last time her tracker went off, six months ago, she was off the coast of Beach Haven, New Jersey. According to her Twitter followers, her updates will be sorely missed.

"She's the queen of the ocean," Fischer told USA Today. "She's a 50-year-old-or-so mature white shark that absolutely dominates wherever she goes."