The Black Sea is characterized by its large continental shelf, water stratification, lack of vertical mixing, highest H2S content of deep waters worldwide, strong freshwater input, increased levels of nutrients and detritus, weak water mass exchange with the Mediterranean Sea, large spatial and temporal variability of physical and chemical properties, about half salinities of those noticed in the world's ocean, slightly different composition of the ionic ratios. Poorer flora and fauna have been previously compensated by their high biological productivity. Relatively few alien species entered this particular environment. Up to the end of the fifth decade of the XXth century the Black Sea underwent major changes which contributed to a severe ecological disequilibrium. Considerable efforts have been devoted after 1990 for the rehabilitation of this still highly endangered sea. Within these joint contemporary concerns the continuous development of Romanian oceanography has enriched Black Sea research. Selected research and monitoring results regarding marine biology, ecology and radioactivity, history of oceanography, research and management programmes / projects are reviewed.