Tagged Great White Sharks in the Northeast: Online Tracker Shows You Their Recent and Past Locations

Great white sharks have been appearing with greater frequency along the Northeast seaboard, particularly near Cape Cod in Massachusetts, where they are drawn to a thriving seal population.

Photo: Ocearch
Last month, the crew of the M/V Ocearch—a specially designed shark research vessel operated by Ocearch Ocean Research—successfully tagged several great whites just offshore from Cape Cod with tracking devices. You can learn more about "Expedition Cape Cod" in a great eight-part video series on YouTube, on their expedition blog, or from this current feature story in The New Yorker (subscription required).

The non-profit organization works to support scientists and researchers around the world, and does an impressive job providing a range of public-facing information about their work and research. One of the most fascinating tools Ocearch provides is a free-to-use, constantly updated worldwide map that shows the most recent locations of tagged sharks.

A quick primer on the tagging technology is important to understand how the map works. In most cases, a device is secured to the shark's dorsal fin, which transmits its location anytime the dorsal fin breaks the water. So the map doesn't display continuous, here's-the-shark-now locations (the device can't transmit through the water), just the location and most recent time the shark broke the surface. (Interestingly, some sharks break the water quite frequently and provide regular updates on their location, while others rarely do so and can travel weeks and hundreds of miles without breaking the surface.)

Once Ocearch receives a "ping" from one of the tagged sharks, the information is displayed on their map. (Orange dots indicate a ping less than 72 hours old, green dots less than 30 days.)

Even better, clicking on any ping pulls up all kinds of great info about the specific shark. For example, as I write this, the map tells me that Katharine—a 14 foot, 2 inch female great white weighing 2,300 pounds—has spent the last three weeks cruising around between Nantucket and Monomoy Island and surfaced last night at 10:27 p.m.

Fascinating stuff—and perhaps a good way to decide if you should purchase a new shark-deterrent wetsuit anytime soon!

“Equipped” is an AMC Outdoors blog, written by Matt Heid.