Physical spawning environment of Sardina pilchardus (Walbaum, 1792) in the eastern coast of Tunisia (Ionian Sea, Mediterranean)

A hydrographic and ichthyoplankton survey was carried out on 63 stations along the eastern coast of Tunisia from 17th to 26th December 2008. The objective was to study the physical features of the Sardina pilchardus spawning areas. The winter conditions were installed. Water column was well mixed and the sea surface temperature mean was around 16.84 degrees C. The entrance of the Modified Atlantic Waters (MAW) in the East of Tunisia was clearly shown. Sardine eggs and larvae represented 35 and 71% of each ichthyoplankton stage, respectively. They were mainly (approximate to 96%) found over the continental shelf. Sardine spawned mainly in the bathymetry range 40-80 m and outer of the MAW area (SSS <37.25). Two main spawning areas were found, the first was found in the north and coastal (south of Kelibia), and the second in the south and far from the coast of Teboulba, with bathymetries of 56 and 79 m, respectively. The surface current played an important role in the distribution of larval stages by the transport, the dispersion and the concentration.