p. 57 - 74 DONNEES CONCERNANT LA LIMITATION DE LA SALISSURE MICROALGALE SOUS L'ACTION DE QUELQUES SUBSTANCES ANTIVEGETATIVES Nicolae Bodeanu Institut Roumain des Recherches Marines Constantza Abstract Tests regarding the action of some antivegetative substances on the development of algal microfouling from in sea submerged metallic plates have been carried out by the biological method of calitative and cantitative analysis. The taxonomic composition of microalgofouling, beeing made the particularly by Pennate Diatoms, was established. Some substances have been found the present a high degree of toxicity. The anti- vegetative substances demonstrate a selective toxic impact on different microphytic algal species.