It is known that the concentrations of the clupeids, and particularly those of sardine, are linked with the upwelling zones in the region.
A short summary of the hydrographic regime in the area is given in the report in the first session.
Sedykh et al. (1979) demonstrated a tendency of increase in upwelling in the Sahara coastal division (Division 34.1.3) since 1972-73, as measured by the Eckman transport. This is confirmed by observations of variations in the intensity of the wind component inducing upwelling in Nouadhibou and Dakar (Rébert, 1979).
No information was available to the Group on changes in the hydrography in Division 34.1.1 during the same period.
Sedykh et al. (1979) and Domanevski and Barkova (1979) related aspects of yearclass strength and growth of the sardine with the observed changes in upwelling.
It should be noted that there are significant differences in the pictures given of the variation in upwelling in Sedykh et al. (1979) and in Domanevski and Barkova (1979).
In view of the importance of the possible relation of the changes in upwelling with aspects of the distribution, growth and recruitment of the sardine resources, the Soviet scientists agreed to provide more detailed information on their observations on the upwelling and the observed changes in the related biological characteristics of the stocks to the CECAF Working Party on Resource Evaluation.
