The aim of the present study is the first to evaluate the ecotoxic state of the marine environment in Anza-Taghazout coasts (Morocco) after installation of two wastewater treatment plants using a natural population of marine bivalves Mytilus galloprovincialis. These coasts are exposed to many discharges generating, thus, different sources of pollutants. These pollutants can modulate the physiological responses of marine bivalves to environmental stress. In this context, a multibiomarker approach consisting of a battery of biomarker evaluation was used to assess the response of these species to stress. In the whole soft tissues of M. galloprovincialis, four biomarkers were evaluated as follows: acetylcholinesterase (AChE), glutathione S-transferase (GST), catalase (Cat), and malondialdehyde activity (MDA). In parallel, physico-chemical parameters were measured in the marine water of Anza-Taghazout within three selected sites: S₁ considered as “hotspot” located at Anza city; S₂ located near of Aourir city; and the third site, S₃ “reference” located in Imouran beach. Our results showed that activities of both glutathione S-transferase and catalase were higher in M. galloprovincialis collected from site S₁, but high values of malondialdehyde and acetylcholinesterase activities were observed successively at S₃ and S₂. Application of integrated biomarker response (IBR) index was suitable for classifying the stress response in the M. galloprovincialis but did not allow to evaluate the level of the xenobiotic exposure in the studied sites. The statistical results did not show any significant differences between the three studied sites, and therefore, S₁ has recently become clean due to the installation of two wastewater treatment plants.

本研究的目的是在安扎-塔加祖特海岸（摩洛哥）安装两个污水处理厂后，首次评估海洋环境的生态毒性状态，这些污水处理厂使用海洋双壳贝类（Mytilus galloprovincialis ）的自然种群。这些海岸暴露在许多排放物中，因此产生了不同的污染物来源。这些污染物可以调节海洋双壳类动物对环境压力的生理反应。在这种情况下，由一系列生物标志物评估组成的多生物标志物方法用于评估这些物种对压力的反应。在M. galloprovincialis的整个软组织中, 四种生物标志物评估如下：乙酰胆碱酯酶 (AChE)、谷胱甘肽 S-转移酶 (GST)、过氧化氢酶 (Cat) 和丙二醛活性 (MDA)。同时，在三个选定地点测量了 Anza-Taghazout 海水的物理化学参数：S ₁被认为是位于 Anza 市的“热点”；S ₂位于奥里尔市附近；第三个站点，S ₃ “参考”，位于伊穆兰海滩。我们的研究结果表明，从站点 S _1采集的M. galloprovincialis谷胱甘肽 S- 转移酶和过氧化氢酶的活性都较高，但在 S ₃和 S ₂连续观察到高值的丙二醛和乙酰胆碱酯酶活性. 综合生物标志物反应 (IBR) 指数的应用适用于对M. galloprovincialis中的应激反应进行分类，但不允许评估研究地点的异生物质暴露水平。统计结果显示三个研究地点之间没有任何显着差异，因此，由于安装了两个污水处理厂，S ₁最近变得干净。