The Lake L'albufera of Valencia
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THE LAKE L’ALBUFERA OF VALENCIA The natural park of the Albufera in Valencia, Ramsar site and area of special protection for birds, with 21.000 hectares, is one of the most important wetlands in Europe and an exam- ple of interaction between mankind and nature. In this hugely valuable natural environment, three ecosystems can be diffe- rentiated: the lake, the marsh and the Devesa (coastal forest). The lake covers practically the same surface as the whole city of Valencia (2.100 hectares) and its maximum depth is only 1.5 metres. Water in the Albufera is fresh, as it comes from the surrounding rice fields. These, in turn, are supplied with water from the Júcar and Turia rivers. More than 14.000 hectares within the Albufera Natural Park are used for rice crops, potentially compatible with the conservation of this natural en- vironment. It is the largest habitat of this protected area. Cropland, paths, canals and ditches make up 70% of the total surface of the Natural Park. Index Between the Albufera lagoon and the Mediterranean Sea, a sand stripe The Albufera of Valencia 1 of 10 kilometres holds La Devesa of the Albufera. La Devesa is a coastal forest of 850 hectares where we can find a recovered dune environment, Environmental Problems 2 but also a wild pine forest. Despite its proximity to a large urban environment, the Albufera bustles Solution: Treating Water with biodiversity. A great part of the international projection of the Albu- with Artificial Wetlands 2 fera of Valencia and its surrounding area is due to the diversity and abun- dance of waterfowl. Some 350 bird species use this area at some point The LIFE ALBUFERA Project 3 during their vital cycle. About 90 of them nest regularly in this Natural Park. In addition, over 800 plant species can be found in the natural park, many of them classified as threatened by extinction. NEWSLETTER Nº 1 LIFE ALBUFERA - April 2015 p1/7 ENVIRONMENTAL PROBLEMS The lake of Albufera is one of the most valuable ecosystems in the Na- tural Park. However, its ecological status is far from what it used to be a few decades ago. Up until the 60s its water was transparent and had a rich and varied aquatic vegetation and fauna. Fishermen say that not so long ago they even used to drink water directly from the lake. Urban, agricultural and industrial growth in Valencia and the surrounding villages caused the degradation of the water quality of the Albufera in the early 70s. Aquatic plants disappeared, as did most of the fish, mo- lluscs, aquatic insects and small mammals. The lack of food due to the low water quality also pushed away birds, whose population was reduced drastically. Therefore, the three most important challenges today are the improve- ment of the water quality, stop the habitat degradation and recover bio- diversity. SOLUTION: TREATING WATER WITH CONSTRUCTED WET- LANDS Constructed wetlands may be part of the solution to recuperate the wa- ter quality in the Albufera, regenerate degraded habitats and achieve a better ecological of this territory. The basic principle of the constructed wetlands is the circulation of water along areas with vegetation. Plants feed from the nutrients present in the polluted water, thus reducing their concentration and leave cleaner water. This simple system has been applied in small towns, isolated rural villages, camping sites and hotels for years. Constructed wetlands in the Albufera, also known as Green Filters in this area, are an innovative progress in the application of this depuration sys- tem, due to their size and treatment capacity. They are designed to treat water from the lake, reducing its organic pollution, and in some cases they can perform a subsequent treatment after the wastewater treat- ment plants (WWTP). Artificial Wetlands in the Albufera have been placed in former rice fields where aquatic vegetation has been planted. This vegetation, apart from treating water from the lagoon, has a second and very important role: recreating natural ecosystems, scarce in the Albufera, thus forming a Natural Reserves network of great value for the visiting avifauna. TANCAT DE LA PIPA TANCAT DE MILIA TANCAT DE L’ILLA NEWSLETTER Nº 1 LIFE ALBUFERA - April 2015 p2/7 LIFE ALBUFERA PROJECT In the Albufera of Valencia – a wetland of high ecological value – measures to comply with the Water Framework Directive have been implemented, focusing on water quality improvement aspects. But only one of these me- asures, the creation of artificial wetlands, can also directly improve habi- tats and bird conservation according to the guidelines on the habitats and birds directives. For this reason, the initiatives proposed by this project pursue the following objectives: 1. Establishing the most appropriate management rules for the artificial wetlands in order to jointly optimise water quality and habi- tat and biodiversity improvement, according to the application of the Water Framework Directive and the Habitats and Birds Directives. 2. Proving that the joint management of the three artificial wet- lands contributes to improving water quality and biodiversity in the Albufera. 3. Setting up a methodology to determine indicators of good conservation status for birds, in order to apply them to other wet- lands of the Natura 2000 Network. 4. Providing recommendations aimed at competent administra- tions to set the basis in the development of site management plans for the Natura 2000 Network and hydrological management plans. THE 4 PHASES OF THE PROJECT AND EXPECTED RESULTS 1 Evaluation of the Artificial Wetlands initial status and Proposal on Management 1 Setting up of 4 Management Plan the Manage- ment in each 4 Implementation Artificial Wet- land 3 Setting up of indicators3 Applying based on the 2 Determi- Matematical modelling ofResults AW and their to the ning the best birds, water and habitats. effect on the lake of l’AlbuferaOverall Wetland Management Monitoring 2 Artificial Wetlands Hydrological and Vegetation Management and Quality of Water, Birds and Fish NEWSLETTER Nº 1 LIFE ALBUFERA - April 2015 p3/7 RESULTS WATER QUALITY Between January and December 2014, a total of 3.5 Hm³ water from the Albufera have been introduced into the three artificial wetlands. Of these, 57% correspond to entries in the Tancat de la Pipa, 28% corresponds to Tancat de Milia and 14% to Tancat de l’Illa. The inlet water shows significant quality differences among Tancats: more polluted in Pipa and Milia and less in L’Illa. In the first two, inlet water contains suspended solids (TSS, average concentration of 49.52 mg / L), organic matter (COD average 61.7 mg / L) and nutrients (TN 4.4 mg N / L and TP from 0.249 mg P / L). The incoming water is rich in microalgae (average values of 3-58 mm³ / L and of 26-110 µg Chl a/ L depending on Tancat), fluent in phytoplankton groups less desirable as cyanobacteria and slightly diverse in zooplankton biomass with domain rotifers and copepods in most cases. The results at the output of wetlands show significant reductions in the entering concentrations. From a biological point of view, wetlands contribute to reducing the concentration of phytoplankton (about 80%) and increase the zooplankton (200%). Consequently, an improvement of the overall ecological status can be observed by the presence of macroinvertebrates. VEGETATION One of the actions being undertaken in the LIFE ALBUFERA Project is to develop a vegetation management protocol (both emergent and submerged), so that the impro- vement of the water quality and biodiversity is being optimized. To do this, we have implemented several plantations in two of the three constructed wetlands of the project during the spring and summer of 2014, and we are monitoring the evolution of these plantations, taking into account the species, water levels, and by contrasting different planting methods. During the summer of 2014, between August and September plantations were imple- mented in various sectors of the artificial wetlands of Tancat de Milia and Pipa. More than 27,000 copies of different species of helophyte vegetation have been introduced, as well as Phragmites australis in greater proportion, followed by Iris pseudacorus, and to a lesser extent, Cladium mariscus, Sparganium erectum, Juncus subnodulosus and Scirpus taber-naemontanii and maritimus and 74 fenced with submerged vege- tation of which should be highlighted the Ceratophyllum demersum for its growth. The harvest of several plots in the Tancat de l’Illa was conducted in September 2014 in order to create spaces for birds and remove biomass. BIRDS The first campaign of tracking the waterfowl breeding in the artificial wetlands of the Albufera of Valencia, has obtained interesting results. For their different configura- tions, the artificial wetlands offer slightly different habitats for waterfowl in relation to the level of flooding, vegetation structure and floristic composition of their plots. It is by studying the variation of microhabitats in a period of two years that we obtain precise information of the habitat requirements and the interactions between the spe- cies. We are now beginning to understand some of the processes in each site: • The Tancat de la Pipa, with much more open lagoons and a wetlands system with sparse vegetation, offers environments suitable to a wider variety of waterfowl spe- cies, but in small numbers. • The Tancat de Milia, with greater coverage of cattails on flooded substrate but with low density, provides a suitable environment for the reproduction of two of the most interesting species for the project: the coot and teals. • The Tancat de l’Illa, with very high cattail coverage and a high density together with abundant fish of small and medium size, is a highly appropriate place for the repro- duction of heron and bittern. NEWSLETTER Nº 1 LIFE ALBUFERA - April 2015 p4/7 DISSEMINATION NATIONAL EVENTS AND EXCHANGES Participation in the Albufera Fair Tancat de la Pipa was represented by Accio Ecologista Agró and SEO / BirdLife and Tancats de Milia and l’Illa by the Fundación Glo- bal Nature.