Integrated biomarker responses and metal contamination survey in the wedge clam Donax trunculus from the Atlantic coast of Morocco.

In Morocco, the marine environment has always been a major occupation for socioeconomic activities (industry, tourism, urbanization, etc.). Thus, this work displays a case study of Taghazout coast in the central Atlantic part of the country, which becomes the center of several development projects, such as the touristic resort Taghazout Bay. In the aim to assess the health status of this coastal ecosystem, a multi-indicator approach based on the response of biomarkers in the wedge clam Donax trunculus was adopted during two years (2016/2017). The undertaken investigations on the response of biomarkers (AChE, GST, MDA, and CAT) in the sentinel species D. trunculus showed an activation of defense mechanisms in this bivalve, which would imply exposure to chemical stress in this ecosystem. The monitoring of seasonal bioaccumulation of cadmium (Cd), lead (Pb), and copper (Cu) by D. trunculus indicates that the bivalves collected have been exposed to these metal sources in the study area. In addition, the correlation study has reported a significant effect of environmental parameters on biomarker response. Overall, the multi-indicator approach has clearly revealed the health status of Taghazout coast registered in a coastal urbanization.

A Multibiomarker Approach to Assess the Health State of Coastal Ecosystem Receiving Desalination Plants in Agadir Bay, Morocco.

The present study aims to evaluate the initial health status of two stations receiving seawater desalination plants in Agadir Bay (Tifnit-Douira and Cap Ghir) and to assess their potential environmental impact on the marine ecosystem health. Six pairs of mussels (Mytilus galloprovincialis) were collected at six sampling sites on a monthly basis over two years. Each pair was homogenized to obtain the postmitochondrial fractions (S9). Toxicological effects were measured using a multibiomarker approach based on either acetylcholinesterase (AChE), glutathione S-transferase (GST), catalase (CAT), and malondialdehyde (MDA) rate. The results show a seasonal variation of the biomarkers: their activities increase in summer and decrease in spring and winter. High activities were recorded during summer in Cap Ghir (17.94 ± 0.88; 5.91 ± 052 nmol/min/mg of protein) for CAT and MDA, respectively. In Tifnit-Douira, low activities were recorded during winter for GST (3.74 ± 0.52 nmol/min/mg of protein) and during spring for the CAT (3.52 ± 0.45 nmol/min/mg of protein). The fluctuations in the activities of measured biomarkers could be attributed to different factors including the changes in environmental parameters, the influence of seasonal variation, and the contamination of the aquatic ecosystem. The data obtained in this study should be taken into account in the monitoring and management of the health of the ecosystems when the desalination plants are established.