Definition of "biosphere"

Patavig is the second of the Macedon system's giant terrestrial planets, and by far the more interesting. Most of the surface is covered by a vast sea of liquid ammonia, in which a unique aquatic ammonia-based biosphere has developed. While the frozen continents are largely bereft of life, a rich bounty of complex organisms — many larger than a human — flourish in the chilly, toxic seas.

2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, PC, scene: Patavig