VALUTAZIONE DELL’IMPATTO DI INVASIONI BIOLOGICHE IN HABITAT PRIORITARI

IMPACT EVALUATION OF BIOLOGICAL INVASIONS IN PRIORITY HABITATS

Abstract

A standardised procedure based on the implementation of ALEX index (ALien Biotic IndEX) was used to assess the ecological quality of marine coastal habitats in relation to the invasion of alien macroalgae. The study was conducted on coralligenous and  Posidonia oceanica meadows in five areas of the Mediterranean Sea. The coralligenous reefs showed a higher abundance of Caulerpa cylindracea and Womerseyella setacea while the P. oceanica meadows were mainly invaded by Acrothamnion preissii.  The index values ranged from 0.48 to 0.90 classifying most sites with good to high ecological quality. The use of ALEX, in conjunction with other ecological quality indices, proved to be a valid approach for the integration of Marine Strategy monitoring plans.