EN
The Algerian west coast is the prime recipient ofsev eral forms of pollution; hence, the necessity for an impact assessment of this coastal pollution using a suite ofr ecommended marine biomarkers, including lysosomal membrane stability in living cells by the Neutral Red Retention Time (NRRT) method, the evaluation ofmicron ucleus (MN) frequency, and the determination ofacet ylcholinesterase (AChE) activity in mussels Mytilus galloprovincialis, sampled from the large, polluted Oran Harbour (OH) and the Maˆarouf( Mrf) marine mussel farm between July 2005 and April 2006. The difference in the variations oft he annual physical parameters between OH and Mrfco rresponds to the influence ofthe domestic and industrial sewage discharged by the city ofO ran. The biological data ofthe mussels (condition index, protein content) recorded at both sites were related to their natural reproductive cycle. This indicated that intrinsic variation between the sites due to different mussel development phases was minimal. The variation in the AChE activity of some organs ofO H and Mrfm ussels, with minimal inhibition in July and a higher NRRT recorded in the granular haemocytes in the Mrfthan in the OH mussels during the autumn and spring, depends on the quality ofthe biotope and on generic stress factors. Moreover, the variation in MN frequency, in general reflecting a non-significant seasonal and spatial genotoxic effect ofthe contamination at the two sampling sites, requires further investigations regarding biotic and abiotic variations.