Scientists love to research sharks, probably because they’re the badasses of the sea. But despite decades of analysis, some basic behaviors of Earth’s most infamous predator remain a mystery. How do sharks move when pursuing prey? Do they avoid other shark species? So a team of biologists from the Hawaii Institute of Marine Biology and the University of Tokyo’s Atmosphere and Ocean Research Institute decided to try an approach that’s popular with extreme athletes: strap on a camera and see what happens.
With the help of Japanese data-logging company Little Leonardo, the researchers built a device that captures video and movement information (with a triaxial accelerometer-magnetometer like a flight-data recorder) but is small enough that it won’t interfere with a shark on the move. They secure the camera to the shark’s fin, where it rides for up to two weeks. Then the device auto-releases and floats to the surface, pinging the research team for pickup.
The footage has been, as ecologist Carl Meyer puts it, astounding. The cams recorded Hawaiian sandbar sharks diving in close formation with other species (including hammerheads and blacktip reef sharks) and chasing members of the opposite sex. The team had never seen multiple shark species congregating. “This is our first ever shark’s-eye view,” Meyer says. “Until we deployed the cameras, we had no idea that these mixed-species shark aggregations were occurring only a few miles from our research institute.” Finally, researchers can keep up with the predator that never stops.