Cachalot

From a #1 New York Times–bestselling author, a sci-fi fantasy set on an aquatic planet, where cetaceans are thriving and humans dying at an alarming rate.

Welcome to Cachalot, a planet made almost entirely of water, an ocean refuge for Earth's marine mammals, rescued from near extinction at the hands of humans thousands of years ago. Free from predators and human impact, the whales thrive in their new home, growing in size and intelligence. Everything is perfect. Until humans decide to establish floating towns on Cachalot, drawn by the planet's abundant natural resources. Now someone or something is killing off Cachalot's human population, a mystery a team of marine biologists has to been sent to Cachalot to solve—a mission that could cost them their lives.
"One of the most consistently inventive and fertile writers of science fiction and fantasy." —The Times (London)