Stock definition: The distribution of anchovy in the Division IXa is nowadays mainly concentrated in the Spanish waters of the Gulf of Cádiz (Sub-division IXa-South, Figure A.1.1). Outside the main nucleus of the Gulf of Cádiz, resilient anchovy populations have been de-tected in all fishery independent surveys (ICES, 2007 b) and previous records on large catches in ICES areas IXa North, Central North and South (Algarve) suggest that abundance in those areas have been high in early years of the time series. In the south, outside the Gulf of Cádiz anchovy is abundant to the East of the Strait of Gibraltar, in the Mediterranean Sea (GFCM, 2002) as well as in northern Africa, where a combined Spanish-Morocco fishery produces landings of up to 12 000 tn (Millán, 1992; García-Isarch et al., 2008).