spatio-temporal patterns of key exploited marine species in the northwestern mediterranean sea主要利用海洋物种的时空模式地中海西北部.pdfVIP

Spatio-Temporal Patterns of Key Exploited Marine Species in the Northwestern Mediterranean Sea 1 1 ´ 1 2 Marie Morfin *, Jean-Marc Fromentin , Angelique Jadaud , Nicolas Bez ` ´ 1 UMR 212 EME, IFREMER (Institut Franc¸ais de Recherche pour l’Exploitation de la mer), Sete, France, 2 UMR 212 EME, IRD (Institut de Recherche pour le Developpement), ` Sete, France Abstract This study analyzes the temporal variability/stability of the spatial distributions of key exploited species in the Gulf of Lions (Northwestern Mediterranean Sea). To do so, we analyzed data from the MEDITS bottom-trawl scientific surveys from 1994 to 2010 at 66 fixed stations and selected 12 key exploited species. We proposed a geostatistical approach to handle zero- inflated and non-stationary distributions and to test for the temporal stability of the spatial structures. Empirical Orthogonal Functions and other descriptors were then applied to investigate the temporal persistence and the characteristics of the spatial patterns. The spatial structure of the distribution (i.e. the pattern of spatial autocorrelation) of the 12 key species studied remained highly stable over the time period sampled. The spatial distributions of all species obtained through kriging also appeared to be stable over time, while each species displayed a specific spatial distribution. Furthermore, adults were generally more densely concentrated than juveniles and occupied areas included in the distribution of juveniles. Despite the strong persistence of spatial distributions, we also observed that the area occupied by each species was