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This work focuses on the assessment of aliphatic hydrocarbons in sediments collected from the western Moroccan Mediterranean coasts. Two zones have been chosen for this study. Zone 1 corresponds to Tangier's bay and zone 2 corresponding to the fringe between Kabila and Kaâ Srass. The aliphatic hydrocarbons were extracted and analysed using chromatographic techniques (GC/FID and GC/MS). The results showed a more important accumulation of aliphatic hydrocarbons in Tangier's bay if compared with zone 2. Levels ranged within 128.8 to 340.31 µg/g dry weight, with two exceptions 611.72 and 648.16 µg/g dry weights and from 5.25 to 22.71 µg/g dry weights, for zones 1 and 2, respectively. Moreover, the aliphatic hydrocarbons distribution proves to be strongly influenced by the nearness to input sources and by oceanographic and hydrodynamic conditions. Thus, two distribution patterns were observed corresponding to the two areas studied. Furthermore, the examination of origin fingerprinting criteria proved the biogenic origin related to phytoplankton, bacteria and continental plant waves. The anthropogenic character of hydrocarbons was also evidenced especially in Tangier's bay, by several chromatographic criteria and was confirmed by the presence of hopanes with predominant C29 and C30 α, β compounds.

In order to evaluate the contamination of the Moroccan Mediterranean coasts by persistent organic pollutants we studied hydrocarbons and linear alkylbenzenes in bivalve tissues (cockles) collected seasonally from several points along the western Moroccan coasts in the Mediterranean Sea. Two fractions corresponding to non aromatic and aromatic hydrocarbons were analyzed by GC/FID and GC/MS. Non aromatic hydrocarbon concentrations vary in the range of 24.1 - 2731 μg/g dry weight (dw) while total n-alkanes vary from 2.2 to 68.2 μg/g. Few exceptions were noted with values up to 243 μg/g (dw), which is high compared to other Mediterranean sites. The presence of an important unresolved complex mixture (UCM) indicated a significant petroleum contamination, confirmed by the identification of 17α(H), 21β(H) hopanes. Biogenic contributions were also detected within the n-alkane distribution (n-C₁₇, n-C₁₈, n-C₂₇, n-C₂₉, n-C₁₇, /Pr, n-C₁₈, /Ph) and by the presence of alkenes. C₁₃, and C₁₄, linear alkylbenzenes were found at concentrations of 478 - 1954 ng/g. and point to pollutant inputs from wastewaters. Polycyclic aromatic hydrocarbons were present in low concentrations below the GC detection limit. The observed seasonal and spatial variations were linked to the magnitude of inputs from marine and land-based pollutant discharges