## 3 Results
With respect to the other polluted site TAD, the GI was lower for the year 2019 only. Some significant changes were found for the BSM site depending on the year. The GI was reduced at BSM site in 2016 and increased at 2017. The air survival time and the dehydration rate were determined in clams over the sites at each year (Figure 4). The lethal time to air emersion was significantly increased at BSC and BSM and decreased at TAD sites in 2016. In 2017, the LT was significantly reduced at the two polluted sites TAD and BSC. The LT was reduced at BSM in 2018 but increased in 2019 and 2020. With respect to the maximum weight loss (WL), the levels were higher at the BSM site at each year compared to the reference site. The WL was also increased at the polluted site BSC in 2018, 2019 and 2020. Correlation analysis between element tissue loadings displaying significant differences from the reference sites and morphological biomarkers were performed (Table 3). The CF was significantly correlated with Ca (r = \(-\)0.33), Cr (\(-\)0.41), Mn (r = \(-\)0.30), Mo (r = 0.37), Nb (r = \(-\)0.41) and Nd (r = \(-\)0.33). Clam age was significantly correlated with Cr (r = \(-\)0.35), Mn (r = \(-\)0.30), Mo (r = 0.43) and Nb (r = \(-\)0.35). The GI was significantly correlated with Ag (r = \(-\)0.37) only. Air survival time was significantly correlated with Ca (r = 0.31), Cr (r = 0.37), Mn (r = \(-\)0.44), Nb (r = 0.37), Sm (r = 0.32) and V (r = \(-\)0.4). The weight loss at time of death during air emersion (dehydration rate) was significantly correlated with Ag (r = 0.48), Cd (r = 0.42), K (r = \(-\)0.32) and Sm (r = 0.37). Taken together, the strongest correlations were obtained with Ag, Cr, Mn and V with either one of the three morphological biomarkers (CF, GI and LT) including the WL during air emersion. Multiple regression analysis revealed (results not shown) that the CF was best predicted by V (\(\beta\) = 0.11), Sm (\(\beta\) = \(-\)0.57) and Mn (\(\beta\) = \(-\)0.1), showing that Sm and Mn reduced clam CF. The GI was best predicted by Mn (\(\beta\) = 0.06), Sm (\(\beta\) = 4.4), Ni (\(\beta\) = 0.66), Ag (\(\beta\) = \(-\)4.75) and V (\(\beta\) = \(-\)0.06), indicating that Ag and V had a detrimental effect on growth. The LT was significantly predicted by tissue levels of Mn (\(\beta\) = 0.23), Sm (\(\beta\) = 14.8) and V (\(\beta\) = \(-\)4). The maximal WL during air emersion was significantly predicted by Cd (\(\beta\) = 153),  
Figure 3: Temporal changes in the growth index of dams. The GI (shell length/age) was determined in clams at each site for over the 5-year period. Legends as in Figure 2.  
Figure 2: Yearly changes in condition factor in _Mya anemia_ claims by site. The CF (total weight/shell length) was determined in clams at each site for over the 5-year period. The filled and doted lines represent the mean and the 5–95 th percentile of the reference site MAB to depict the natural variation of CF in clams. In an attempt to seek out long-term trends, Fourier transformation and rescaled range analyses were preformed (Figure 5). The rescale range analysis of the CF was H = 0.941, 0.977 and 0.964, suggesting that these changes were not random (white noise, H = 0.5) and show a long-term trend toward a decrease in the CF over time. Fourier transformation was used to filter out reduced inter-individual variability for each year. With respect to CF (Figure 5A), the reference site changes revealed a strong drop in 2018 and returned levels to those found in 2016 in 2020, hence a period of 5 years. At the polluted sites, the amplitudes of the peaks are much smaller than the peaks in the CF over time. The corresponding peak values of the CF were 0.941, 0.977 and 0.964, suggesting that these changes were not random (white noise, H = 0.5) and show a long-term trend toward a decrease in the CF over time. Fourier transformation was used to filter out reduced inter-individual variability for each year.