Application of the CARLIT index along a biogeographical gradient in the Alboran Sea (European Coast).

An index, based on littoral communities assemblages (CARLIT), was applied to assess the ecological status of Northwestern Mediterranean coastal waters, following the requirements of the European Water Framework Directive. The biogeographical particularities of the Alboran Sea suggested a reassessment of this index, and that was the main objective of this work. Due to these biogeographical particularities, two regions were proposed in the studied region, with new reference conditions for each region. Subsequently, by means of a multivariate analysis, littoral community abundances and the CARLIT index were compared with factors related to geomorphology, biogeography and anthropogenic pressures. Overall, the biogeographical component determined the distribution of littoral communities. In contrast, the ecological status yielded by the index only was significantly related to anthropogenic pressures. The results pointed out that the reassessment of the CARLIT index was suitable to evaluate the ecological status of the Alboran Sea.