[Distribution of hydrocarbon residues in the sediment from Bizerte lagoon (Northern Tunisia)]

The study of hydrocarbon residue by infrared spectrophotometry in the deposits of the Bizerta Lagoon allows us to recognize a polluted zone sector of the Menzel Bourguiba Arsenal. The Eastern part of the lagoon, a zone of "oyster parks" is not affected by pollution. Its average contents of hydrocarbon residues are clearly below the maximum content determined by international regulations. The distribution of hydrocarbon residues in the superficial sediments following three well differentiated zones, reflects the weak hydrodynamism in the lagoon. The vertical variations of this pollution agent contents show the preferential accumulation of the terrigenous material, from lake Ichkeul , in the western part and the weak rate of sedimentation in the eastern zone.