p. 233 - 246 THE INFLUENCE OF THE EUTROPHICATION ON ZOOPLANKTON COMMUNITIES IN THE BLACK SEA WATERS Florica Porumb Romanian Marine Research Institute Constanta Abstract The cycle of quantitative evolution of the pelagic copepods com- munities in the Black Sea Romanian waters, strongly eutrophicated, is investigated during two distinct periods: between 1970 and 1979 and 1980-1986. During the second period, as a result of eutrophication, an important numerical increase of copepods has been recorded, comparing to the first period. Opportunist species such as Oithona nana and Acartia clausi, to which Oithona similis could be added, presented a net tendency of quantitative prevelance in the Copepods population structure belonging to the second period, 1980-1986.