Fluvial protected areas as a strategy to preserve riverine ecosystems—a review

Fluvial ecosystems are essential for life on Earth. Despite this recognition and the growing implementation of restoration programs, measures aimed at halting riverine biodiversity’s decline have had limited success, so far. The implementation of protected areas has been the cornerstone of terrestrial and marine conservation. However, this strategy has only been seldomly applied to the protection of fluvial ecosystems and there is still no clear evidence of its effectiveness. We reviewed existing literature in scientific journals and reports from conservation agencies and analysed existing protection policies dedicated to rivers as well as several case studies throughout the world. Our main aim is to understand the potential advantages and drawbacks of dedicated fluvial protected areas, comparing to terrestrial protected areas and even to the total absence of protection. We also delved in the process of implementing fluvial protected areas, namely in what concerns relevant spatial scales, conservation priorities, stakeholders’ involvement and mitigation measures to potential threats. In total 173 references were retained after a comprehensive search on Google Scholar, SpringerLink, Scopus and ResearchGate. These studies revealed that, despite contradictory results, terrestrial protected areas provide some degree of protection to riverine ecosystems contained within their borders, namely through increased abundances and species richness of some specific groups. Comparatively, however, dedicated fluvial protected areas, designed to accommodate the uniqueness of these systems, hold a much higher potential. Yet, data regarding its effectiveness is still scarce, mainly due to the lack of general guidelines and resources to evaluate performance following establishment, which prevents stronger conclusions.