Spatio-temporal organization patterns of demersal assemblages of the east coast of Corsica (Mediterranean Sea)

The paper deals with the spatio-temporal organization patterns of demersal assemblages along the east coast of Corsica. We analysed data collected by the first standardized experimental bottom trawl surveys performed in this region from 1994 to 1999 (MEDITS programme). The use of a multiway table method (STATIS-CoA) showed that the spatial organization pattern of the demersal assemblages of eastern Corsica was highly stable during the period studied. This pattern was structured around three bathymetrie areas (i) the continental shelf (between 50 to 200 m depth), (ii) the upper slope (from 200 to 500 m) and (iii) the deeper slope (from 500 to 800 m), but it did not show any heterogeneity in relation with latitude. Along the east coast of Corsica - characterized by one of the lowest fishing pressure rates within the whole northern Mediterranean Sea and by the scarcity of information on fishing patterns - our results contribute to the basic information required for multispecies fishery management. They suggest that all the trawlable areas along the east coast of Corsica could be considered as a single biogeographical unit, possibly split up into three bathymetric strata. Furthermore, if compared with results from studies carried out in Mediterranean regions with more intensive fishing rates, our results might provide a quantitative basis for achieving a better understanding of the impact of fishing pressure on organization patterns of demersal assemblages.Original Abstract: Le present travail analyse l'organisation spatio-temporelle des assemblages demersaux de l'est de la Corse par une approche quantitative. Cette region, qui se caracterise par un des plus faibles niveaux d'exploitation des ressources demersales de l'ensemble du nord de la Mediterranee, a jusqu'ici ete tres peu etudiee. Dans ce contexte, nous analysons les donnees recoltees lors de la premiere serie de campagnes de chalutages mise en oeuvre entre 1994 et 1999 selon un protocole d'echantillonnage standardise (programme MEDITS). L'utilisation d'une methode multitableaux (STATIS-CoA) a permis de mettre en evidence la forte stabilite interannuelle de l'organisation spatiale des assemblages etudies. La composition specifique des assemblages est structuree autour de trois regions bathymetriques (i) le plateau continental, (ii) le haut de la pente continentale et (ii) le talus, mais elle ne presente aucune heterogeneite en fonction de la latitude. Nos resultats constituent une premiere base de conn