The artificial stimulation of biological purification of sea-pollutant hydrocarbons requires phosphorus supply. The concentrations, corresponding to the optimal bacterial growth, depend, in particular, on ionic strength. They range between 2 and 8 × 10−4 M for waters in which the salinity is close to the mean salinity of an oceanic environment and between 1.5 and 3 × 10−3 M when these waters receive a significant supply of freshwater or when salinity is naturally weak. Inhibition of bacterial development has been observed either with a microflora, or with pure strains for concentrations higher than the upper limits of concentrations so defined.
