ABSTRACT Freshwater biodiversity is rapidly declining worldwide due to human activities and resulting environmental changes. Despite the uniqueness of many freshwater ecosystems, they have often been overlooked in the designation of protected areas. The European Union's (EU) network of protected areas, the Natura 2000 network (N2K), plays a crucial role in halting biodiversity loss, including freshwater ecosystems and fish species. This study explores the conservation potential of Special Areas of Conservation (SACs) and Sites of Community Importance (SCIs) within N2K for 40 native freshwater fish species in Spain, 20 of which are listed in Annex II of the Habitat Directive. We used 10,035 field observations of these species and environmental variables (at reach scale and catchment level) to model species distributions using BIOMOD2. These predictions were translated into maximum and minimum potential presence–absence maps for each species. The study assessed how well species distributions are covered by the N2K and whether species are listed in the network's Standard Data Forms (SDFs), which are essential for biodiversity documentation and management in the EU. We aimed to identify mismatches between predicted species distributions, N2K site coverage and species listed in SDFs. Results showed high average N2K coverage for all species (around 60%), with no significantly higher coverage for those in the Annex II of the Habitat Directive. Nonetheless, models revealed that species were absent from approximately 30% of N2K sites where they are officially designated as priorities in the SDFs. In contrast, endangered species were predicted in several N2K sites where they are not legally recognized. Finally, the study mapped areas where these mismatches occur, improving understanding of the conservation status of these 40 native fish species in Spain, highlighting discrepancies between official data and predicted distributions, and suggesting a need for updated legal protections, targeted management and potential designation of protected areas.
Lanzas et al. (Wed,) studied this question.