A statistical contribution to the study in ecology of sardine (Sardna pilchardus Walb.) in the central Adriatic

Abstract

1)       A considerable coincidence has been noticed between the data resulting from the analysis of the size of the 1949 Sardine catch and of the outcome of the 1949 Sardine tagging in the waters of the central Dalmatian region where an intensive tagging was carried out. The Sardine displacements were congruous, and in substance they were                            c o n v e r g e n t l y  directed at the inshore channels and the coast of the mainland.

2)       The 1949 Sardine catch, in relation to the estimated total size of population, was a minimum one. The corrections for systematic errors, were not considered when the size of population was computed.

3)       A divergent retreat of Sardine occurring in stages toward the main sea, i.e. in the contrary direction of the displacement during the fishing season, was manifest along the central Adriatic shore when the fishing season came to an end in October. The abiotic factors of the environment, being most important in the occurrence of this movement, have been employed in the attempt to explain the phenomenon of Sardine spawning taking place (in both the inshore and offshore waters) in different seasons.