Every year on February 2 we commemorate World Wetlands Day, a celebration of the floodplains, marshes and coastal areas all over the planet that permanently or periodically have their soil drenched. Pantanal Wetland is home to the largest of these, covering an area of over 170,500 km², it spans the states of Mato Grosso and Mato Grosso do Sul in Brazil, as well as Paraguay and Bolivia. This rich habitat is home to more than 4,000 animal and plant species.
However, in 2018 the theme of this celebration will not be these continent-sized areas. The motto of this year's World Wetlands Day is urban wetlands, which throughout the history of humankind have been continuously reclaimed for the construction of buildings, streets and gardens. Why do we need to reflect on this? Because the consequences of reclaiming urban wetlands are disastrous for the inhabitants of urban areas; these include flooding, water shortages, changes in temperatures and rainfall patterns. It is this global call to action that is on the agenda in 2018: to rethink how we treat our urban wetlands.
The world’s largest cities all have their famous landfill sites: the charming Marais (which means marsh in French) in Paris is an ancient wetland formed by the River Siene, which was reclaimed in the 13th century. The consequences of this included flooded basements and the closure of streets and tourist attractions, representing enormous financial losses.
Here the situation is similar. Many neighbourhoods in cities such as Rio de Janeiro, Recife and Fortaleza were also built on landfill areas, with the suppression of mangroves. These areas act as a natural barrier, and when removed they leave coastlines and their inhabitants exposed to extreme weather events such as tidal waves, rains and strong winds. The most expensive area of real estate per square metre in Brazil on Avenida Delfim Moreira in Rio de Janeiro, once a complex of wetlands, was reclaimed at the beginning of the 20th century. In 2016, this avenue was invaded by seawater, destroying part of the pavement, invading building garages and destroying kiosks, causing enormous damage.
Wetlands provide countless benefits for cities. In 2012, during hurricane Sandy, the mangroves of the east coast of the United States prevented damage in the region of 625 million dollars. In order to guarantee water security in New York, hundreds of millions of dollars were invested in purchasing and preserving marshland areas.
Even so, with these incontestable facts demonstrating the need to preserve marshlands, half of these ecosystems in the world have disappeared in the last hundred years. Many of the urban problems we face are directly related to rich and fragile ecosystems, such as wetlands, not being preserved. These areas were considered for a long time to be dirty, but are actually are the kidneys of the planet.
Wetlands are responsible for filtering and storing water and reserving high quantities of quality water for many Brazilian cities. Wetlands are also where a large amount of evapotranspiration takes place, contributing to rainfall levels and replenishing groundwater.
Some recent data has revealed that in 2017, 15% of Brazilian municipalities suffered water scarcity, and this number looks set to increase. It is time for us to think of new strategies for Brazilian urban wetland preservation and conservation. These should be seen as spaces for permanent preservation and kept conserved and free from human interference. Degraded wetlands should be recuperated so that our cities can better adapt to extreme climatic events in the future. Making Payments for Environmental Services (PES) obligatory in cities whose water supply comes from wetland areas, for example, could guarantee their preservation and maintain a relationship from which both rural producers and urban users can gain.
If we wish to get our cities out of the muddied waters in which they find themselves, with reduced rainfall and water shortages, we need to look at our wetlands before it all goes down the drain.
Júlio César Sampaio, co-ordinator of WWF-Brazil’s Cerrado Pantanal Program
Cássio Bernardino, WWF-Brazil conservation analyst