A work trip to a conference in Valencia in Spain provided the opportunity to learn about and see the Albufera of Valencia; a shallow lake in excess of 2,000 ha located to the south of the city. Little more than a metre deep, it is of huge importance for its wildlife, supporting around 90 breeding bird species and up to 50,000 wintering waterfowl. Around 8,000 years ago, the Albufera was open to the Mediterranean Sea but gradually became cut off by sandbanks. Originally some 30,000 ha in extent, it slowly reduced in extent through both sedimentation and its margins being progressively claimed for agriculture, principally rice production.
There have been major issues with water quality, notably nutrient enrichment, since the 1980s, mainly as a result of spreading urban development from the city and the surrounding agriculture. The formerly clear waters, full of aquatic waterweeds, have given way to algal dominated turbidity. The population of 1,000 or so pairs of Coot declined to just a few tens of pairs as the vegetation disappeared. As the floating vegetation nesting platforms of Whiskered Terns disappeared, so did the terns. To try to resolve this problem a partnership of organisations came together to form the LIFE+ Albufera Project, funded by the EU. Between 2007-2012, three areas of rice fields close to the lake were converted to wetlands designed to enhance water quality. These 'tancats' were carefully land-formed and then planted with a range of emergent plants such as Phragmites and Typha that will extract the nutrients from the water as it flows through. Water flows down a series of terraces before being pumped back up into the lake. One of these areas, the Tancat de la Pipa was created in 2008 on the northern side of the lake. Its construction was supported by the Ministry of Agriculture, Food and Environment and is managed by SEO Birdlife and Accio Ecologista Agro. Early results show that significant improvements have been made.
I was shown around the site by the excellent guys from SEO Birdlife (the Spanish Ornithological Society, notably Pablo Vera, who has undertaken many of the bird studies in recent years. Despite some declines, the Albufera is still a fantastic place for wildlife. The bird list is impressive, with many species doing well. For example, latest estimates suggest 60 pairs of Purple Heron, 400 of Squacco Heron, 200 pairs of Glossy Ibis, 50 pairs of Little Bittern, 600 pairs of Gull-billed Tern and 1,000+ pairs of both Common and Sandwich Tern. Around 40 pairs of Red-crested Pochard, a local priority species, breed annually. There have been re-introductions of both Marbled Teal and Red-knobbed Coot, a nest-building pair of the latter causing great excitement on my visit.
A short video here: The Albufera of Valencia