Potential risk of harmful algae transport by ballast waters: The case of Bilbao Harbour

► Between 1997 and 2006, 41,900,980.34 ballast water tn were loaded in Bilbao Harbour. ► Discharged ballast water between 1997 and 2006 in Bilbao Harbour was 13,272,709 tn. ► Bilbao Port is a ballast water source, mainly to European harbours. ► It would be risk of exporting at least 10 toxic phytoplankton species as H. akashiwo.