Upward movement of cool and nutrient-rich sub-surface waters towards the surface often leading to exceptionally rich areas. There exist various types of upwelling. For fisheries, the most important type is the wind-induced coastal upwelling where the upward movement is a consequence of wind stress (along shore) and Eckman transport (offshore). (FAO Fisheries Department (2003) World Fisheries and Aquaculture Atlas. CD-ROM. Rome, FAO. 2nd ed.)
