Spatial and temporal distribution of some demersal fish populations in the Adriatic Sea described by GIS technique

Abstract

       In order to enhance the knowledge about spatial and temporal distributions of demersal popu­lations in the Adriatic Sea, which is very important for common fishery policy, the data of relative abundance of some selected demersal species from two extensive trawl-surveys carried out in two distinct periods of time have been analysed; the first one, undertaken in 1948-1949, called HVAR Expedition, and second one, carried out in 1996-1997, under the scope of EU MEDITS program (International Mediterranean trawl surveys).

       Taking into account the information system possibilities for a clear, cartographic description of demersal population space and time distributions, GIS (Geographic Information Technique) has been applied utilising quantitative data of the relative abundance, standardised as catch ration (kg km^-2) of the following fish species: hake (Merluccius merluccius), striped mullet (Mullus barbatus) and fish group Chondrichthyes. Applying this technique common, shared and dynamics features of some demersal Adriatic stocks have been clearly described.