New article: Geographic distribution of threats to Mediterranean freshwater fish

A new article published in the journal Diversity & Distributions and led by Miguel Clavero addresses the spatial distribution of threats and imperilment of freshwater fish in the Mediterranean basin.

The level of imperilment of Mediterranean freshwater fish is amongst the highest recorded for any group of organisms evaluated to the date. This article describes the geographical patterns in the incidence of threats affecting Mediterranean freshwater fish and test whether the effects of specific threats are spatially related to the degree of imperilment of fish faunas.

We recorded the main threats to 232 endemic freshwater fish species and used data on fish distributions from IUCN to characterize the spatial patterns in the incidence of those threats (as % of species affected). We studied the relationships between threat incidence and two estimators of imperilment at two spatial scales (10×10 km and basins) using partial least squares regressions (PLSR) that incorporated the effects of species richness and mean range size.

We found that the main axis of variation in the incidence of threats to freshwater fish split areas mainly affected by invasive species from those areas where species are threatened by pollution and agriculture. Wherever invasive species and water extraction were predominant threats fish assemblages consistently tended to be more imperiled.

As far as we know, this is the first large-scale analysis on the spatial relationships between the incidence of threats and level of imperilment of any taxonomic group. Our results highlight the primary role of invasive species and water extraction as drivers of native fish declines in the Mediterranean Basin. Large-scale patterns described here should be generated by local-scale impacts of both threats on fish biodiversity, widely reported in Mediterranean areas. This strongly points out that controlling invasive species and reducing overexploitation of freshwater resources should be conservation priorities for Mediterranean freshwater systems.
——————————————–

El grau de perill actual en que es troben els peixos d’aigua dolça de la conca Mediterrània es troba entre els més alts descrits per qualsevol grup biològic analitzat. En aquest article es descriuen el patrons geogràfics de la incidència de les principals amenaces que afecten aquest grup i es testa fins a quin punt la distribució d’aquestes amenaces concretes es relaciona amb el greu de perill de les faunes de peixos descrites en diferents zones. faunas.