World Wetlands Day: River alterations affect sturgeons, Danube’s flagship species

We celebrate World Wetlands Day on the 2nd of February to show the important role of wetlands and floodplains for people and the planet. This year’s theme  “Wetlands for a Sustainable Urban Future” highlights the important role of wetlands for sustainable urbanization.

Wetlands contribute in many ways to our quality of life and our own survival. Wetlands and floodplains work like a highly efficient sewage treatment system, absorbing chemicals, filtering pollutants and sediments, breaking down suspended solids and neutralising harmful bacteria. They are also the most biologically diverse ecosystems on Earth.

Naturally, we can easily recognise rivers as the most popular wetland sites. In Europe, more than 81 million people of different cultures and languages call the Danube River basin home. People directly benefit from the many services the river provides – drinking water, flood protection, source of income and spots for rest and recreation. Over the last century, the total floodplain area of the Danube has been reduced by 80%. The Delta floodplain was the least reduced, by 35%.

On World Wetlands Day, we have to recognise the effects that river alterations have on the Danube flagship species – sturgeons. Habitat alterations like channelisation, river straightening and dike building, have an immediate impact on sturgeon spawning and feeding. Sturgeons are a valuable indicator for river health. Water pollution and siltation negatively impact spawning sites, as well as the physiology and fertility of spawning fish. Because of the sturgeons’ long life-cycles, late maturity and long intervals between spawning, they take very long to recover from decline caused by environmental and human pressures.

Fortunately, there are initiatives for wetlands restoration and conservation of sturgeons. “Life for Danube Sturgeons” is part of the strategic efforts of WWF and the European Union to protect and restore sturgeons and their home. While we focus on the riverine communities, in another project we work together with partners to bring back to life key wetlands in Hungary, Croatia, Serbia, Romania and Bulgaria. These ambitious projects aim to increase the river capacity by the equivalent of 4800 Olympic sized swimming pools (12 million m³) and to restore over 7422 football pitches worth of wetland habitat (53 km²) by 2020.

Happy World Wetlands Day!