Albufera Lagoon, located some 12 km south of Valencia city (Spain), is a shallow freshwater lagoon of surface area 2 800 ha. It is separated from the Mediterranean Sea by a large sandbank. The lagoon and surrounding wetlands are a Site of Community Importance (SCI) under the Habitats Directive and a Special Protected Area (SPA) under the Birds Directive. The lagoon is an important site for birds, particularly wintering and breeding species that use it for resting and nesting. The endangered bird species living in the area include Eurasian bittern (Botaurus stellaris), marbled teal (Marmaronetta angustirostris) and white-headed duck (Oxyura leucocephala). However, despite various levels of protection, the lagoon water fails to meet quality objectives set by the Water Framework Directive (WFD 2000/60/EC)). Specifically, the lagoon is hypertrophic, meaning there are excess nutrients in the water. In an effort to improve water quality, three artificial wetlands – green filters – have been created (in place of rice fields) since 2008. However, improvements are necessary if they are to effectively support the management requirements of the Natura 2000 network or to achieve WFD objectives.
The objective of the LIFE ALBUFERA project was to demonstrate effective management of artificial wetlands to improve both water quality and habitat conditions for bird species, to meet the requirements of the Water Framework Directive, the Birds Directive and the Habitats Directive. The project aimed to define, implement and optimise management procedures for three artificial wetlands in the area of l’Albufera SPA. The goal was to enable each hectare of constructed wetland to treat 5 000 m3 of lagoon water per month. The project sought to set management objectives for restoring the ecological potential of the wetland, to define a methodology for determining good status indicators for bird conservation applicable to other Natura 2000 wetlands, and to conduct an assessment of the socio-economic impact of the management measures on the local economy.
The LIFE ALBUFERA project beneficiaries established management procedures for three artificial wetlands to optimise synergies between improvement of water quality and the status of bird species of conservation concern. The project proved that joint management of these wetlands can contribute to improved water quality and improved habitat quality and biodiversity in l'Albufera SPA. The beneficiaries established a methodology to determine good status indicators for bird conservation, and produced a plan setting out the basis for the future management of Albufera’s protected areas.
The project’s extensive data gathering and monitoring activities included recording physico-chemical parameters of water in the lagoon and in the three artificial wetlands, as well as levels of phytoplankton, zooplankton, macroinvertebrates and sediments at different times of the year. The results demonstrated that it is possible to improve the poor water quality of the Albufera Lagoon, through the successful operation of artificial wetlands as a green infrastructure for water treatment. This raises the possibility of enlarging the area of artificial wetlands.
Environmental benefits were mainly related to the improved water quality of the Albufera Lagoon. Poor water quality, due to eutrophication, directly impacts the area’s ecological potential. The project actions implemented at the three artificial wetlands demonstrated how eutrophic waters can be successfully treated. Specific environmental benefits included the treatment of 6.65 hm3 of Albufera Lagoon water in the three artificial wetlands over two years, and the removal of nutrients, phytoplankton and suspended materials from the lagoon water: 11.2 tonnes of total nitrogen, 0.5 tonnes of total phosphorous, 198.2 kg of chlorophyll and 83.8 tonnes of suspended solids. Up to 34 mg dry weight/m2/day of zooplankton were production in the artificial wetlands; the project team concluding that the artificial wetlands were highly efficient in reducing the biomass of phytoplankton to produce zooplankton biomass. The actions improved vegetable cover in the marsh vegetation habitat (15.4 ha), increased the flow-free area in areas 100% covered by vegetation (4 ha) and increased the area of water with submerged vegetation (32.2 ha). Six species of reproductive birds improved their conservation status during the project: gadwall (Anas strepera), purple heron (Ardea purpurea), glossy ibis (Plegadis falcinellus), squacco heron (Ardeola ralloides), black-winged stilt (Himantopus himantopus) and western marsh harrier (Circus aeruginosus). Bird species favouring high water quality clearly benefitted from the presence of the artificial wetlands. The project team removed 587 kg of biomass of invasive exotic species. Native species were also introduced and monitored in the artificial wetlands, for example, the Valencia toothcarp (Valencia hispanica). The project published technical manuals and guidelines for artificial wetland management to optimise water quality, and improve habitat and biodiversity. Another document was addressed specifically to the competent administrations establishing the basis for a management plan for the Albufera. All these documents are applicable to other Natura 2000 network wetlands and hydrological management plans. The project’s approach was soon being replicated in two other Natura 2000 sites in Spain: Mar Menor in Murcia and S'Albufera in the Balearic Islands.
In terms of policy and legislation, the project is directly relevant to the Water Framework Directive, the Nitrates Directive, the Habitats Directive and the Birds Directive. In particular, it has demonstrated the feasibility of managing artificial wetlands by jointly promoting the objectives of these directives. The project team concluded that the artificial wetlands provide direct socio-economic benefits through improvements in water quality. For instance, improved water quality has increased the number of fish in Albufera Lagoon, which favours fishing; tourist activity has increased (to the benefit of restaurants and other local businesses); and hunting activities are favoured by the artificial wetlands. The project’s activities have increased acceptance and awareness of the environmental role of artificial wetlands, and have played an educational role. An increase of the available area of artificial wetlands would allow to carry out part of the urban wastewater treatment process and therefore replace the current treatment system.
Further information on the project can be found in the project's layman report (see "Read more" section).