Kamchatka contains probably the world's greatest diversity of salmonid fish, including all six species of anadromous Pacific salmon (chinook, chum, coho, seema, pink, and sockeye). Biologists estimate that a sixth to a quarter of all Pacific salmon originates in Kamchatka. Kuril Lake is recognized as the biggest spawning-ground for sockeye in Eurasia. In response to pressure from poaching and to worldwide decreases in salmon stocks, some 24,000 square kilometers (9,300 sq mi) along nine of the more productive salmon rivers are in the process of being set aside as a nature preserve.
Bears have a good time during the spawning season.