Wastewater impact on macroalgae biodiversity in Essaouira coast (Morocco)

Some events could affect the biological diversity and living resources in marine areas. under the influence of human activities,the atlantic ocean ecosystem has changed. taking this into consideration,a new approach of studies is absolutely necessary in order to estimate the major modifications that occurred on macrophytobenthos,under the influence of harmful factors that disturb the quality of marine environment and its biodiversity. the aim of this study is to determine the macroalgal biodiversity of the essaouira coast in relation to the main abiotic factors. two stations were chosen: moulay bouzektoune station (s1) located at 15 km far from essaouira as a control,and the bab dokkala station (s2) located in the city where some industrial and domestic wastewaters are rejected without any treatment. the results show a high diversity of macrophytobenthos at s1 station with 79 taxa of macroalgae including 56 rhodophyceae,14 chlorohyceae and 9 phaephyceae,whereas at s2 station,only 44 species were inventoried including 31 rhodophycae,8 chlorophycae and 5 phaeophycae some physico-chemical parameters were measured to assess the pollution impact degree on the two stations studied. the results show that in bab dokkala station,where it pours sewage from the city of essaouira without pretreatment,there is an increase of nitrite,ammonium,total phosphorus and orthophosphates,with a slight decrease of ph. thus,the algal biodiversity and abiotic parameters show that bab doukkala station is impacted by domestic wastewater coming from the city of essaouira in comparison with the preserved one: moulay bouzerktoune. © 2017,university of mohammed premier oujda morocco.