[Toxic effect of four heavy metals on the growth of unicellular marine algae].

The growth inhibition of phytoplankton, resulting from Cd, Cu, Hg and Pb in sea water, has been studied on 18 monospecific strains belonging to different taxonomic groups. Data obtained pointed out that all species are very susceptible to Hg, and slightly to Pb. Effects of Cu and Cd vary with species, but Cu appears to be more toxic with dinoflagellates than with diatoms. In the authors' opinion, these results, obtained under laboratory conditions, cannot immediately be extended to the natural environment.