Unusually high for winter time satellite-derived chlorophyll-a concentrations southwest of Iberia were detected in February 2001. Analysis of satellite data (SeaWiFS, AVHRR, sea level anomaly from TOPEX/POSEIDON and ERS) revealed that the phytoplankton-rich waters were associated with an extremely long filament (up to 400 km) induced by eddy-eddy interactions occurring in the vicinity of the continental margin. The eddy interaction occurred simultaneously with an accumulation of coastal fresh water over the shelf. The event promoted an export of biogenic material offshore along with an estimated shelf flushing in a 5 to 6 day period that resulted in a dramatic offshore growth of phytoplankton. A description of the event is given and preliminary estimates of the cross-shelf transport are presented and discussed.