The park protects a wetland environment and an adjacent marine area
The park is twinned with a Spanish wetland, the Doñana National Park at the mouth of the Guadalquivir. The two parks share a number of features including significance for bird-life and semi-feral horses, and proximity to a pilgrimage site (Saintes-Maries-de-la-Mer and the Hermitage of El Rocío). The site was formally twinned with the Danube Delta Biosphere Reserve Ramsar site by an agreement between the governments of Romania and France, 1992. Ramsar site no. 521.