Emily Chan
In the first known case of its kind, a great white shark near Bermuda gobbled up a porbeagle shark with a tracking device attached to it. To make matters even more shocking, the porbeagle shark was pregnant!
Porbeagle sharks are found throughout the Northern Atlantic Ocean and parts of the oceans in the Southern Hemisphere. They can grow to around 12 feet in length and have muscular forms and long, sharp teeth. But in the end, all those menacing features are not enough for it to escape predation.
“This is the first documented predation event of a porbeagle shark anywhere in the world,” Brooke Anderson, the lead author of the study and a marine fisheries biologist at the North Carolina Department of Environmental Quality, said.
In October 2020, the pregnant female porbeagle was tagged with a satellite transmitter and a pop-off satellite archival tag (PSAT) near Cape Cod.
The devices aimed to track the shark and collect data on her depth and geographical range over time. Satellite transmitters are permanent, but the PSATs are removed after a year.
The depth of a porbeagle is measured by temperature and pressure data from the PSATs. Any irregularities in temperature and pressure indicate that the shark has died or the tag somehow came off.
In this case, the porbeagle shark moved between the ocean surface and 328 feet below until December 2020. That was when she began diving up to 2,600 feet deep during the day and floated at about 650 feet during the night. As she moved south toward waters off the shore of Bermuda, she maintained the pattern.
On March 24, 2021, temperature patterns indicated that the depth had changed drastically. Previously, the shark had been swimming through waters that ranged from 43.5 to 74.3 degrees Fahrenheit.
But on that day, the tag recorded temperatures between 61.5 to 76.5 degrees Fahrenheit, even though it remained at a similar depth.
Sign up for Chip Chick’s newsletter and get stories like this delivered to your inbox.
