The average values of environmental variables at the foursampling stations are summarized in Table S1. Among the 11 measurements, the values of pH ranged around 8.3, with the minimumat station A and the maximum at station D. The transparencyand DO showed an increasing trend, while the values of NH4-Ndecreased along the gradient of stress (from station A–D). Concen-trations of NO3-N, SPR and SiO3-Si, were low at stations C and D,and high at station A and B (Table S1). The lowest concentrationsof COD and NO2-N occurred at station C, and highest at stations Band D.