p. 141 - 148 ACTION DU FLUOR COMME ELEMENTE POLLUANT DE L'EAU DE MER Serbanescu Octavian, Radu Mihnea, Elvira Cuingioglu et Bilal Icmet Institut Roumain de Recherches Marines Constantza Abstract In the present paper the authors establish the influence of the fluor ion resulted from a sulphuric acid and chemical fertilizer plant, on the marine flora and fauna. Owing to the different degree of solubility of the flour compounds, the laboratory experiments were carried out with calcium fluoride - (CaF2)- and with sodium fluoride - (NaF). The concentration of the respective solutions ranged between 2 and 100 mg per litre. Observations were made on the behaviour of various species of fish, mollusks and crustaceea, in solutions of varying concentration.