Demersal Assemblages on the Soft Bottoms off the Catalan-Levante Coast of the Spanish Mediterranean

Abstract EN

The analysis of 255 bottom trawl samples obtained in annual experimental surveys (2007–2010) along the western Mediterranean shows the existence of five well-defined demersal assemblages that follow a depth distribution: (a) upper shelf assemblages, including two assemblages differentiated by the type of substrate (sand-muddy and terrigenous muddy bottoms); (b) a middle shelf assemblage; (c) an upper slope assemblage; (d) a middle slope assemblage.

Faunally, they are dominated by fish (37% of 452 total species), followed by crustaceans (22%), molluscs (17%), echinoderms (9%), and other invertebrates (15%).

The assemblages identified showed major alterations on the shelf and shelf edge and less pronounced ones on the upper and middle slope.

The average diversity values were more or less high, evidencing the high species richness in the western Mediterranean.

The identified assemblages may facilitate future multispecies fisheries management based on an ecosystem approach.