A Silent Spring for our era, this eloquent, urgent, fascinating book reveals how just 50 years of swift and dangerous oceanic change threatens the very existence of life on Earth. Legendary marine scientist Sylvia Earle portrays a planet teetering on the brink of irreversible environmental crisis.In recent decades we've learned more about the ocean than in all previous human history combined. But, even as our knowledge has exploded, so too has our power to upset the delicate balance of this complex organism. Modern overexploitation has driven many species to the verge of extinction, from tiny but indispensable biota to magnificent creatures like tuna, swordfish, and great whales. Since the mid-20th century about half our coral reefs have died or suffered sharp decline; hundreds of oxygen-deprived "dead zones" blight our coastal waters; and toxic pollutants afflict every level of the food chain.Fortunately, there is reason for hope, but what we do--or fail to do--in the next ten years may well resonate for the next ten thousand. The ultimate goal, Earle argues passionately and persuasively, is to find responsible, renewable strategies that safeguard the natural systems that sustain us. The first step is to understand and act upon the wise message of this accessible, insightful, and compelling book.