Samples collected during Week I (black dots 1–10), and samples collected during Week II (black squares, 11–24). The corresponding loading plots (biomarker variables and environmental variables) are superimposed on the scores plot. Abbreviations are as follows: CAT Catalase, LPX Lipid peroxidation, GST Glutathione S-transferase, ORAC Oxygen radical absorbance capacity, SOD Superoxide dismutase, totGSH total glutathione, GSSG.A oxidized glutathione Absent, GSSG.P oxidized glutathione Present, GR.A Glutathione reductase Absent, GR.P Glutathione reductase Present. One sample from 11 August was not considered in the PCA analysis as there were no replicates.