People track how much exercise they get using a Fitbit, and now there’s a similar device for sharks. These accelerometer tags use the same computer chip as the human Fitbit and track how many times a day a shark beats its tail, any changes in body pitch and posture, and the shark’s orientation in the water. All that, plus the depth and temperature of the water. “Our main goal with these things is to look at their fine-scale behavior...so these tags are kind of the ‘what are they doing’ tags,”