Spatial patterns of β-diversity under cumulative pressures in the Western Mediterranean Sea

Abstract

Understanding the spatial dynamics of biodiversity is an essential issue in marine ecologyand requires combining information at local and regional scales. β-diversity is animportant measure of biodiversity that informs on the differences in communitycomposition between sites and, thus, in the species turnover in the community structure.In this study, we analysed and predicted the spatial patterns of β-diversity for fishes,invertebrates and the demersal assemblage along the Iberian Mediterranean coast. Weused Bayesian Bootstrap Generalized Dissimilarity Models (BBGDMs) to study theeffects of environment and human pressures on the β-diversity of invertebrate, fishes andthe entire demersal assemblage from 1994 to 2015 using different time windows toaccount for temporal variability. Then, we used these relationships to predict the spatialpatterns of β-diversity in the whole Iberian Mediterranean coast. Our results highlightedthat the regional spatial patterns of β-diversity were best described by bathymetry and acumulative index of coastal impacts. We identified specific regions with the highest β-diversityin the study area, which were complementary to hotspots of species richness andpresented different degree of overlapping with existent marine protected areas. Overall,our study illustrates that by modelling spatial turnover using β-diversity we can betterunderstand and predict spatial variation of biodiversity and the effects of particularvariables, providing relevant information to end-users and policy makers for designingspecific spatial conservation and management strategies.