p. 77 - 93 QUELQUES ELEMENTS CONCERNANT LA PRODUCTIVITE BIOLOGIQUE DE LA MER NOIRE EN FACE DU DELTA DU DANUBE Adriana Petran, Marian-Traian Gomoiu, Nicolae Bodeanu et Victoria Tiganus Institut Roumain de Recherches Marines Constanta Abstract On the basis of the observations and measurements carried out in 1976-1977, some elements characterizing the structure of the marine ecosystem in front of the Danube Delta are presented in the paper. Although the ecological factors from the predeltaic area record qualitative and mostly larger quantitative fluctuations, the density and biomass values of the phytoplankton, zooplankton and benthos prove that the biological productivity of the area is high.