An exciting foray into Earth's inland waters, the remarkable species they contain, and the conservation challenges of protecting them. We call Earth "the blue planet" because oceans cover 71 percent of its surface. But this description ignores the diverse inland waters—streams, lakes, wetlands, and ground waters—that are so important to global biodiversity. These crucial ecosystems are home to about ten percent of all known species, many of which are extraordinary, and some of which are critically endangered. In Beyond the Sea, David Strayer introduces readers to the world's most remarkable and varied inland waters, including volcanic lakes more corrosive than battery acid, catastrophic floods that carried ten times as much water as the Amazon River, ground waters miles beneath our feet that are home to unique microbes, and vast lakes that fill only once a century. These varied ecosystems support a wide array of remarkable and unique species, such as tiny animals that can become "reversibly dead," mussels that seduce fish, and lungfishes that have evolved to meet the myriad challenges posed by inland-water habitats. Because humans have used—and abused—inland waters so intensively for everything from drinking water to sewage disposal, many species around the world that depend on them are already extinct or in desperate peril. Strayer explains the damage caused by human activities and outlines the solutions that are needed to sustain and restore inland-water ecosystems and their inhabitants. Proving that the sea isn't the only watery realm of mystery and wonder, this book illuminates the secrets, science, and amazing denizens of the overlooked waters in our backyards.