Results presented in this article report the first assessment of at least 3 volatile selenium species (MeSeH, DMSe, DMDSe) in marine water and air. Dimethyl selenide (DMSe) was the main compound encountered and the total concentration of the volatile selenides was found to be correlated with the marine plankton biomass as measured through chlorophyll a content. Estimation of a net selenium flux from the ocean to the marine atmosphere has been established. This gaseous flux corroborates previous hypotheses on selenium cycling and indicates that maritime emissions are a major source of selenium to the atmosphere in the Mediterranean basin. ¿ American Geophysical Union 1996