Répartition des principales aires de ponte de la sardine en fonction des conditions de milieu dans le golfe du Lion

From October 1965 to April 1966, sardine laying in the Gulf of Lion was studied by the Institute of fisheries laboratory of Sète. Plankton fisheries, at two levels (surface and 5 m), were conducted each month on 26 stations distributed over the whole continental shelf. A total of 236 traits were carried out, at surface level and at depths of 5 m, with Hensen nets, dragged at a speed of about one knot, and using a flow-meter, evaluating the volume of filtered water. Moreover, hydrological results concerning the sardine laying season were used, representing 800 observations on environmental conditions. The collected material represents 50 255 eggs and 7 758 larvae preserved with Baker formalin. Its laboratory study included: egg and larva count as well as the evaluation of the vitality percentage, qualitative and quantitative estimation of phytoplankton and zooplankton. Filtered water measurement enabled the conversion of the figures provided by each sample to standard values which could then be compared to each other.