Escapement is a term used in fishery management, particularly for anadromous salmon populations during the last adult phase of their life cycle. When salmon return to their natal stream to spawn, fishery managers how many spawners are required to keep the run sustainable. They also need to determine how much spawning habitat is available in the river system and what the carrying capacity is. The number of spawners determined from these considerations is the escapement number, or spawning escapement.
If fishery managers conclude that spawning escapement can be met, based on test fisheries and spawner count, then seasonal harvests maybe given to different fishery sectors.