The Albuferas de Adra in crisis: a comprehensive review demanding urgent conservation action

Abstract

The Albuferas de Adra constitute one of the most ecologically significant wetlands in southern Spain. As a permanent lacustrine system within a semiarid Mediterranean environment, the site holds exceptional conservation value and is protected as a Natural Reserve, a Ramsar Wetland of International Importance, and a Natura 2000 Special Protection Area for Birds and Special Area of Conservation. Despite this extensive legal protection, the wetland is undergoing marked ecological deterioration driven by intensive agricultural activity in the surrounding watershed, habitat loss and fragmentation, and the proliferation of invasive species. These pressures have resulted in a sustained decline in water quality, characterized by increasing salinity and nutrient enrichment, with direct implications for ecosystem integrity and biodiversity. Ecological responses to these stressors are substantial. Native reed beds (Phragmites australis) are being progressively replaced by unvegetated zones and halophytic vegetation. Significant population declines have been documented in six waterbird species, most notably the globally endangered Oxyura leucocephala, a key species underpinning the site’s international relevance. The marsh associated bird assemblage has also experienced structural simplification, with ten species lost or reduced, indicating advanced habitat degradation. The endemic and globally threatened fish Aphanius iberus has disappeared or sharply declined in recent years, while the regionally endangered amphibian Hyla meridionalis shows signs of probable decline.  Drawing on public datasets and authors´ long term research, this review demonstrates that cumulative anthropogenic pressures are compromising the ecological functionality and medium-term viability of the Albuferas de Adra. Additionally, a persistent disconnect between the wetland and local society has limited its visibility in governance processes. Effective conservation and restoration actions—particularly improved agricultural management and control of invasive species—are urgently required. Nature based and hydrological strategies, informed by experiences in Doñana and the Mar Menor, could enhance ecosystem resilience and support compliance with the EU Nature Restoration Law.