Variation of C. nodosa density in control sampling sites and in impacted sampling sites at each sampling time (T1 = August, T2 = October, T3 = January, T4 = April). As a preliminary analysis at each time, the sampling sites of each treatment were pairwise compared through a one-way ANOVA. No significant differences were found among sampling sites within the two “control” and “impacted” groups at each sampling time. The box plots were built merging the observations of each sampling site for each sampling time and treatment.