Odds are you’ll never see the ocean from the point of view of a school of sharks — unless you’re willing to make that the last thing you’ll ever see. That’s why we should be grateful for oceanographers at the University of Hawaii and the University of Tokyo. As they are reporting today at an oceanography conference in Hawaii — co-sponsored by the Association for the Sciences of Limnology and Oceanography, the Oceanography Society, and the American Geophysical Union — they have been attaching cameras and sensors to various species of captured sharks and releasing them back into the ocean to do, you know, shark stuff.
Some of what the researchers are discovering is overturning previous theories of shark behavior. Lazy critters — except when they’re looking for dinner — sharks were always assumed to move with as little tail power as possible and instead rely on gliding. But onboard accelerometers now show that they make more of an effort than that, preferring powered swimming to a simple drift. The deeper the sharks go, the slower they move; and when they’re near the ocean bottom, they often simply swim about in aimless circles. Tiny brains do not, evidently, lend themselves to busy days.
But the most striking part of the new studies is simply the shark’s eye view of the world — which is equal parts scary and thrilling. Little fish get out of their way fast, which is wise. The sharks themselves appear quite content to travel about in schools made up of multiple shark species, neither especially loyal to their own kind nor especially fearful of any others. But again, they’re sharks. They may not have much to do, but they don’t have much to be afraid of either — except, of course, of humans, who, through fishing, kill an astounding 100 million sharks per year.