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Gaertner, J; Bertrand, Jacques; Relini, G; Papaconstantinou, C; Mazouni, N; De Sola, L; Durbec, J; Jukic Peladic, S; Souplet, Arnauld. |
The species richness pattern of groundfish species in the entire northern Mediterranean Sea was examined at 3 spatial scales: region, large biogeographical zone and basin. We analysed 1914 trawl hauls collected using a single sampling design in the trawlable areas of the continental shelves between the Strait of Gibraltar and the Strait of Dardanelles (from 36.3 to 45.7 degrees N and 5.3 degrees W to 28 E). Spatial pattern in species diversity was assessed using complementary methods (Chao2 estimates of total species richness, mean species richness and beta diversity). No matter which scale was used, the expected longitudinally decreasing trend in species richness, which has been widely described in previous studies, did not appear when comparing estimates... |
Tipo: Text |
Palavras-chave: Lessepsian; Large scale; Mediterranean Sea; Groundfishes; Beta diversity; Species richness. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3569.pdf |
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Merigot, B; Bertrand, Jacques; Gaertner, J; Durbec, J; Mazouni, N; Mante, C. |
The multi-component aspect of species diversity of groundfish assemblages was examined on the basis of a set of experimental trawl surveys conducted on the east coast of Corsica. We analysed and compared the structuration of diversity within three different bathymetric strata: the continental shelf (60-120 m depth), the upper slope (250-400 m) and the lower slope (450-570 m). For each of these three bathymetric strata, we simultaneously analysed 12 indices that are theoretically complementary and relate to 4 diversity components: (1) the number of species, (2) rarity, (3) evenness and (4) taxonomic diversity. Principal component analysis based on Spearman's correlation coefficients was carried out to investigate empirical relationships between the selected... |
Tipo: Text |
Palavras-chave: Mediterranean Sea; Corsica; Taxonomic relatedness; Bathymetry; Diversity indices; Demersal fish. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3512.pdf |
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Gaertner, J; Bertrand, Jacques; De Sola, L; Durbec, J; Ferrandis, E; Souplet, Arnauld. |
The spatial structure of demersal fish assemblages on the continental shelf of the NW Mediterranean Sea was examined on a large scale between the Straits of Gibraltar and the Gulf of Lions. In contrast to its predominant role in the spatial distribution of species composition, described worldwide, it seems depth has only a limited effect on the distribution patterns of the total abundance and diversity of demersal fishes. In addition, evidence is provided for the division of the whole study area into 3 geographical fish assemblages. The influence of Atlantic inputs and the semi-permanent Almena-Oran hydrographic front play a key role in defining the Alboran Sea as a specific fish fauna area. Moreover, the clear differentiation between 2 distinct... |
Tipo: Text |
Palavras-chave: Mediterranean Sea; Management units; Species diversity; Assemblage structure; Demersal fishes. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-3623.pdf |
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