Escapement is a term fishery managers use to identify the number of fish needed to successfully spawn and sustain the run within healthy historical numbers.   This escapement goal number is different for each species and river, and is carefully established by the Alaska Board of Fisheries.  The escapement numbers and goals are woven into a complex management plan for each river system, with specific directives for each species and specific dates where certain numbers must be achieved to avoid potential restrictions and even closures. Conversely, if a run is overly abundant and exceeds the upper end of the escapement numbers, managers can liberalize or increase limits to encourage additional harvest.  In the world of salmon, everything revolves around escapement numbers and having real time, accurate methods for counting fish becomes paramount to responsible management.