Into the great wide ocean Life in the least known habitat on Earth

A fact-filled tour of the ocean and its sometimes improbable denizens. Why do people drown in the ocean? Because they inhale water and die. But why? It's one of many questions to which Duke biology professor Johnsen turns, explaining that whereas most of the human body is "only slightly denser than water," we can float only so long before we begin to sink, succumbing to the physics of water pressure, and "water is surprisingly heavy and thus exerts substantial pressure, even at shallow depths." This fact, Johnsen continues, constitutes a touchpoint for scuba diving instruction, training in an activity that is both fraught with peril and essential to the pursuit of oceanography. Indeed, by Johnsen's account, it's a wonder that science is done at all in the pelagic portion of the ocean, which is to say, everything but the bottom of the sea, which is its own world. Doing research in the open ocean can kill a person in many different ways, from attacks by unfriendly fish to mechanical malfunctions and more, and in any event it's hugely expensive to operate a research vessel ("the ocean doesn't have a smell," he writes, "but the ships certainly do. Outside, they smell of diesel, and inside they smell of ice cream mixed with the 'butter' in microwave popcorn"). Johnsen's prose is often dense with both scientific terminology and scientific concepts, but he asks and answers fascinating questions (even if you're not a marine biology nerd): Why are so many fish silver in color? (The silver is a kind of camouflage, resembling light flashing in water.) How is it that green sea turtles can find their way, year after year, across thousands of miles to a "tiny volcano in the South Atlantic"? (They're guided by Earth's magnetic field.) Must sharks constantly move forward? (No.) A pleasing excursion into the deep for scientifically inclined readers. Copyright (c) Kirkus Reviews, used with permission.