p. 127 - 146 LES DEVELOPMENTS MASSIFS DU PHYTOPLANCTON DES EAUX DU LITTORAL ROUMAIN DE LA MER NOIRE AU COURS DE L'ANNEE 1989 N. Bodeanu et Anca Roban Institute Roumain de Recherches Marines Constanta Abstract On the basis of a rich nutritional support and under the circums tances of some favourable hydrological features, in the waters along the Romanian coasts, during 1989, a good deal of algal blooms more than in any previous years were produced, a great number of algal species gave enormous numerical densities and the total quantities of phytoplankton were some of the highest ones. This paper deals with the peculiarities of phytoplankton structure, dynamic and distribution from the given zone in 1989, the algal species producing these blooms and the main conditions which favourized them as well as the ampleness of algoflora development comparatively with the previous periods.