Environmental impact on the growth and productivity of

Seasonal fluctuations, occurring during 2022, in mussels (Mytilus galloprovincialis) cultivated in different sites of Cala Iris Sea of the Moroccan Mediterranean coasts were investigated biometric parameters. The significantly higher (p<0.05) contents of the total weight (38.48 g), the fresh flesh weight (FFW) (7.93 g) and the dry flesh weight (DFW) (1.47 g) of Mytilus galloprovincialis registered in summer period were coincided with the maximum phytoplankton biomass (1.0774 μg/l), and the seawater temperature (20.29 °C) and salinity (39.60 PSU). Significant high (p<0.05) values of length (L (72.29 mm), height (H) (42.61 mm) and width (W) (27.81) (27.81 mm) were also observed in the season of summer. Positive correlations were observed between salinity, and temperature, and the growth of the animals. Based on the biometric parameters studied for the bivalves, it can be concluded that the best sales period for these bivalves was the summer season, due to a good content of the meat and a good size value of mussels. For a good cultivation and marketing of mussels, it is necessary to take into account the factors related to climate change.