Tales of Russia’s Sacred Sea, Lake Baikal are told by Peter Thomson, Environment Editor at the public radio program The World. Peter describes visiting the world’s deepest, oldest, and largest supply of fresh water in his new book, “Sacred Sea: A Journey to Lake Baikal.” For scientists, Baikal is an enigma: at once both a healthy and a dying ecosystem. Peter eloquently describes diving deep beneath cold, shimmering seas. The waters are unbelievably clear thanks to “the zillions of epischura trawling at any one time like a vast armada of aquatic vacuum cleaners, filtering Baikal’s water with extraordinary efficiency.” These shrimp-like critters are consumed by remarkable fish called “golomyonkas.” These fish swim perpendicular like seahorses and are, in turn, food for nerpas, the Baikal Seal. Despite the clash of two very different fundamental faiths, complete with mirages and miracles, Peter finds hope in those struggling to save Lake Baikal.