From the surface of the ocean, it’s hard to see any visible signs of life below. But this remarkable ecosystem is teeming with life—life that is increasingly under environmental stress. And it is often the predators that sound the earliest warning signs.  By tracking a wide variety of ocean predators, the Tagging of Pacific Predators (TOPP) project provides essential cutting-edge information about the state of the ocean’s health and the challenges facing all its inhabitants. Acclaimed science writer Pamela S. Turner takes readers along with four predators—a leatherback sea turtle, a bluefin tuna, a great white shark, and a Sooty Shearwater—on their remarkable journeys. This full-access look will change the way readers view our blue planet.