Environmental organization World Wide Fund for Nature (WWF) included Danube in it's „World’s Top 10 Rivers at Risk“ study. According to the data, infrastructure works, embanking, excessive fishing, weather changes and pollution are the main causes that threaten to irreversibly affect 10 of the world's most important rivers.

Danube is the only river in Europe mentioned in the WWF report, along with La Plata and Rio Grande / Rio Bravo (America), Nile - Victoria Lake (Africa), Murray-Darling (Australia), Yangtze, Mekong, Salween, Ganges and Indus (Asia).

Danube is Europe's second largest river, with 2,780 kilometers spread along ten countries. According to the report, 80% of Danube's wet zones were lost in the past 200 years because of human interventions - embanking, canals, draining and navigation improvement works.

New infrastructure works are still planned in the Trans-European Network for Transport - TEN-T, designed to eliminate rapids and improve navigation. Changes may affect 500 kilometers on the Danube, including one of the sturgeons' last place to lay eggs.

Romanian track of the Danube is considered as the last part where the river runs free, being included by WWF in the most important 200 natural areas in the world.