Balearic Islands vs Algeria: two nearby western Mediterranean elasmobranch assemblages with different oceanographic scenarios and fishing histories
Authors
Ordines, F. (Francesc); Massutí, E. (Enric); Moranta, J. (Joan); Quetglas, A. (Antoni); Guijarro, B. (Beatriz); Fliti, K. (Khaled)Editor's version
http://www.icm.csic.es/scimar/Date
2011Type
articleKeywords
community descriptorsbathymetric trends
environmental factors
fishing mortality
threatened species
Abstract
In this paper we compare the elasmobranch composition, depth-related trends of species and community descriptors (abundance, biomass, mean fish weight, species richness and diversity) of the Balearic Islands Archipelago and Algeria (north- and southwestern Mediterranean, respectively). The samples used in this study were collected in bottom trawl surveys between 36 and 779 m depth. Generalized linear models, linear regression, cluster and similarity percentage analyses, and generalized additive models were used to compare the two areas. Twenty-nine elasmobranch species were caught, 12 of them common to both areas, 7 appearing only in the Balearic Islands, and 10 only in Algeria. The bathymetric distributions of species were, in most cases, best fitted to uni-modal response curves. The models for species common to both areas showed similar bathymetric trends, except for Etmopterus spinax, which in Algeria showed a maximum abundance lo¬cated 154 m shallower than in the Balearic Islands. ...