Socialist Federal Republic of Yugoslavia
Regarding rivers, the Danube was navigable throughout its entire course in Yugoslavia, linking the ports of Belgrade, Novi Sad, and Vukovar with Central Europe and the Black sea. Long stretches of rivers Sava, Drava and Tisza were also navigable.
Sturgeon
A 2013 study on the critically endangered sturgeon populations in the Danube River Basin determined that ongoing illegal fishing activity and caviar trade is threatening the future of Danube sturgeons. Jutta Jahrl, a conservation expert with the World Wildlife Federation stated that "Romania and Bulgaria are home to the only viable wild sturgeon populations left in the European Union, but unless this sophisticated illegal fishing is stopped, these fish are doomed”.