Macroalgae are a good element for assessing the ecological quality of coastal waters. As such, this indicator has been included in the strategy for monitoring coastal water masses. In view of results on this parameter during this first campaign determining the diversity and spatio-temporal distribution of marine algae in all stations concerned by the study, we were able to evaluate the health of the study area coast water mass. The algae distribution differs from one station to the other according to the season and according to human factors, to give a water mass at low quality.