Catch shares are fishery management programs that allocate fishing privileges in the form of a specific portion of the total annual catch quota. These programs range from individual transferable quotas to community-based management systems such as sectors. While catch shares take many forms, in general they allocate the quota to allow fishing entities—individuals, communities, cooperatives, etc.—exclusive access to a portion of the quota, but require that fishing cease once that entity's share of the quota is met.
Science-based annual catch limits are essential if catch shares are to be effective and if requirements to end overfishing and rebuild depleted fish populations are to be met. These limits ensure that the amount of fish taken each year remains at levels that allow fish populations to reproduce and maintain an adequate biomass to support maximum sustainable catch. After science-based catch limits have been determined, the quota can be allocated to participants in the fishery. This allocation must be done with careful consideration of the socioeconomic changes that may result.