The rich biological productivity within the Peru-Chile current system depends mainly on wind-driven coastal upwelling, which brings colder, nutrient-rich, subsurface waters into the illuminated upper layer, promoting high phytoplankton productivity whish is available for zooplankton and ultimately for fish. Off central Chile (29-39°S), where strong mesoscale eddies and meanders characterize the Coastal Transition Zone (CTZ), we are using hydrographic data, hydroacustic fish-biomass data and satellite information of wind stress, sea level anomalies and chlorophyll, to investigate linkages between mesoscale eddies and meanders and pelagic fish spatial variability. Satellite and in situ data showed that mesoscale structures have a strong association with primary production enhancement in the CTZ. In this region, mesoscale eddies have a coherent vertical structure above 600 m depth, and generate an offshore transport of 2x10(6) m³ s-1 which would be exerting an important influence on upper trophic levels in oceanic waters. A good relationship between mesoscale eddies and temporal-spatial fish distribution has been observed. The different responses of biological-physical interactions associated with mesoscale structure are also discussed. Grant from FIP, FONDECYT N°1040618 and Fisheries Research Institute