Today’s guest blog has been written by José Alves, Conservation Ecologist at University of Aveiro, and Maria Dias, Marine Science Coordinator at BirdLife International, over the controversial decision to build a commercial airport in an area important for waterbirds.

In our letter published today in Science, we highlight the contradiction between the recently appointed EU Commission’s intention to shift EU economies to more sustainable models of growth (The European Green Deal), and the environmental permission recently issued by an EU member state (Portugal) for the construction and operation of an international airport at the heart of the largest wetland in the country, the Tagus estuary.

This estuary hosts the largest concentrations of waterbirds in Portugal and is the second most important wetland for these species in Iberia. The importance of the Tagus estuary for biodiversity extends well beyond Portuguese borders; it is a designated Special Protection Area (European Birds Directive), a Wetland of International Importance (Ramsar Convention), an Important Bird and Biodiversity Area (Birdlife International) and also classified as a Nature Reserve under national law.

The Tagus estuary is a major international hub for migratory waterbirds and other bird species using the East Atlantic Flyway, connecting breeding areas across the northern hemisphere to wintering areas in Africa, for an estimated 300,000 waterbirds © Carla Marques da Silva (Wikimedia Commons - CC BY-SA 3.0)

Our argument is that this decision by an EU member state violates two of the main pillars of the Green Deal – to tackle the global problem of climate change, and to reverse the biodiversity crisis. Despite the substantial increase in local carbon emissions that a second airport in the capital area would generate, Lisbon currently holds the banner of European Green Capital.

Ironically, Lisbon’s bid for European Green Capital award benefited from its proximity to this nature reserve, even though the flight paths for the proposed new Lisbon airport will irreplaceably disrupt some of the most important areas for waterbirds in this wetland, with aircraft flying below 200 meters within the protected area.

Waterbirds move around the Tagus in large flocks which can exceed tens of thousands of birds, as they take advantage of the complex mosaic of wetland habitats sculpted through millennia. For example, flocks of 80,000 black-tailed godwits, a species listed by IUCN as threatened with globally Near Threatened with extinction, which breed in Iceland, the Netherlands and other northern European countries, use the Tagus each spring to feed and rest during their annual migration to sites further south. Several other species that breed across the arctic and temperate Europe, many of which are declining sharply in number, also depend on this wetland.

Black-tailed godwits on the estuary would be threatened © Verónica Méndez Aragón

Despite the impact of Covid-19 on air-traffic, the private company promoting and financing the new Lisbon airport ANA owned by French group VINCI, has announced that it remains firm in its commitment to move forward, and the Portuguese government publicly supported such intentions in June, July and September 2020, when the Covid-19 impact on the aviation industry is very clear.

This is a striking example of a European state attempting to disregard conservation laws, international agreements and publicly-stated plans to move towards a more sustainable and carbon-neutral future. Given the Tagus estuary’s role in supporting species from across the migratory flyway, including species that benefit from publicly-funded conservation programs on many of their range states, other nations may consider holding Portugal accountable for the consequences of this development.

The Environmental Impact Study that preceded the issuing of the environmental permit has been heavily criticised, due to lack of data, technical errors and adoption of subjective criteria. The Portuguese Environmental Agency issued the controversial environmental permit based on a favourable statement by the board of directors at the Institute for Nature Conservation and Forestry, the governmental institution responsible for evaluating impacts on birds, overturning their own technician’s recommendation. Compensation measures will be impossible to implement effectively, given that about half of the Tagus estuary will be impacted and cannot be replaced.

We urge the Portuguese government to reconsider this development and take the opportunity of having Lisbon as the European Green Capital to become European Green Leaders of the movement towards an increasingly sustainable future.

If we cannot enforce protection granted by national and European law and international conservation agreements in a developed country, how can we expect this to happen in impoverished major global biodiversity hotspots?

Letter in Science: Alves, J.A. & Dias, M.P. 2020. Portugal’s airport threatens wetlands. Science 369.