Anchoveta has a wide geographical distribution in the South Eastern Pacific Ocean, from Zorritos (4°30’ S) in Northern Peru to Chiloé (42°30’ S) in Southern Chile (Serra et al., 1979). There is a Northern-Central Peruvian stock managed by Peru; a  Southern Peru/Northern Chile stock, managed by both Peru and Chile, and a “Central-Southern Chile stock”, managed by Chile, according to (Cahuin et al. 2015).

However, the most recent research on population structure found a clear separation of the Central-Southern Chile stock. The southern area (Valparaíso to Los Lagos regions) showed less than 5% mixture with anchoveta from the Southern Peru/Northern Chile stock and from Atacama and Coquimbo regions (Niklitschek et al. 2018). Bays in the central area (Atacama and Coquimbo regions) have the appropriate conditions to facilitate the development and retention of its individuals, limiting their migration and interaction with other populations (Espíndola et al. 2018). Thus, the Central-Southern Chile stock is now split into two profiles: Atacama (III) - Coquimbo (IV) and Valparaíso (V) - Los Lagos (X).

Atacama (III) - Coquimbo (IV) profile is structured as an assessment unit, as the new evidence is not conclusive on stock identity.