2.5. Statistics
Statistical analyses have been performed by using the statistical
software package XL-STAT-Pro. Shapiro–Wilk test has been applied to
evaluate the normality of the variables and Pearson correlation has
been performed between mean annual metal concentrations in water,
metal concentrations in sediment samples and biological indices. The
criteria used in the statistical analysis for all those chemical concentrations
lower than the method detection limits, was to assign the half
value of the detection limit. Significant differences were determined
by considering a probability lower than 0.05 (p b 0.05).