The studied area was divided in two regions (Tramontana Region, C. Creus-C. La Nao and Levantine Region, C. La Nao-C. Palos), in order to use the historical series of acoustic evaluation data (survey ECOMED), it is recorded in the Tramontana Region since 1990.
The period in which the surveys were carried out corresponds to the recruitment season of the species (November – December). The acoustic evaluation provides an estimation of the recruitment of the species. They are two recruitment areas: one located between Barcelona and the south of the Ebro River Delta (the most important) and other in Rosas Bay.
The studied area was divided in two regions (Tramontana Region, C. Creus-C. La Nao and Levantine Region, C. La Nao-C. Palos),

1.- Tramontana region. The estimated total biomass for the whole area in 2005 (9 000 tons) is three times less than in 2004. There is no trend in calculated biomass since 1996. For this area, the surveys suggested that the recruitment was very low from 1996 to 2000, the population appeared to recover in 2001 and 2003, but it declined for 2004–2005.
The landings, although with a light increase in 2002 (unfortunately, no acoustic data during 2002 were provided), present negative trend. CPUE in 2005 is higher than in 2004.

2.- Levantine Region. The estimated biomass for 2005 was very low and the landings show the strongest negative trend for all the Mediterranean regions.
It is important to note that for the last three years there was a gradual increase in the estimated biomass of other small pelagic species (mainly the three species of horse mackerel and bogue) which are either eggs and larvae predators or compete for the resources with anchovy. As regards 2005, the biomass of sardine and anchovy represented 40% of the total estimated biomass, in contrast to 63% and 83% in 2004 and 2003, respectively.