Researchers tracking a large shark may have stumbled on a disturbing first-of-its-kind discovery after recovering one of the tags.
The apex predator, a 7‑foot pregnant porbeagle shark, was caught by scientists off the coast of Massachusetts in October of 2020 and tagged with two tracking devices.
One of the devices affixed to the fish’s fin was designed to transmit a signal when it broke the surface of the water. The other, called a pop-off tag, pops off after roughly a year and floats to the surface, providing scientists with critical data.

The tags …