Factors structuring reproductive habitat suitability of Engraulis encrasicolus in the south coast of Sicily

Egg and larval abundance, obtained from annual summer cruises carried out in the Strait of
Sicily during 6 years (1997 to 2002), was used to identify the spawning and retention areas of
the anchovy Engraulis encrasicolus. Larval amino acid composition was used to analyse the
nutritional condition of the larvae collected during the 2002 survey. As the anchovy spawns
along the south Sicilian coast, but mainly in the north-west and middle parts of the coast, the
higher number and larger size larvae in the south-east end of the Sicilian coast indicated that
larvae were transported by the main branch of the Atlantic-Ionian Stream and retained in the
south-east end of the Sicilian coast (Cape Passero). This retention process, however, did not
always favour the nutritional condition of the larvae, because the larvae were not transported to
an area with a higher primary production or with a higher stability. In 2002 larval amino acid
concentration was higher in the spawning areas than in those areas where the larvae were
transported to, indicating a lower nutritional condition of the larvae in the nursery areas. The
lack of enrichment and concentration processes, and low primary production in this area which
limited body growth rate may explain the low locally reproducing anchovy population in the
south coast of Sicily.