Abstract
In the present study, I intended to investigate the pollutant exposure to metals, bisphenols and UV filters, and oxidative stress in blue mussels (Mytilus edulis) with different sizes in two suspected polluted locations in Trondheim (Høvringen and Korsvika) and a control group (commercially obtained). The size dependency of the catalase activity was studied in three different size groups of blue mussels Mytilus edulis L.: small (S, length 2.5cm-3.5cm), medium (M, length 3.5cm-4.5cm) and large (L, length 4.5cm-6cm). The level of antioxidant defense was estimated from the catalase (CAT) activities in the digestive gland homogenates. In general, there was a positive correlation between the catalase activity versus the length and weight of the different groups with the large > medium > small sizes of mussels. Also, a significant positive correlation was found between the length versus the catalase activity for the Høvringen group (r = 0.46, p = 0.02). The high CAT activity observed implies a higher concentration of H2O2 production which is supposed to be proportional to the level of pollutants in the tissue of the mussels,- This further suggests that,- the significantly higher catalase activity found in the larger sized mussels compared to the smaller sized mussels could be related to the larger sized mussels having more pollutants than the smaller sized mussels. However, due to the closure of the laboratory during the corona, the pollutants analysis could not be concluded and metal results from mussels obtained at the same locations that I analysed in 2019 have been used for comparison. The high catalase activity reflected the high concentrations of metals: cadmium, lead, zinc, iron and copper found in the mussels collected from Høvringen and korsvika compared to the control group. With a significant difference between the Pb (ANOVA, F = 16.4, p = 0.0037) and Fe (ANOVA, F = 27.2, p < 0.001) concentrations between the different groups. The concentrations of Cd, Zn, Pb and Cu in the mussels found at Høvringen and Korsvika were higher than the normal concentrations of metals expected in mussels according to the Norwegian classification of environmental quality in fjords and coastal waters. The concentrations of Pb and Cd in mussels collected from Høvringen (Pb = 24.64 µg/g and Cd = 10.29 µg/g ) and Korsvika (Pb = 6.12 µg/g and Cd = 10.51 µg/g) exceeded the upper limit set by EU in mussels for human consumption (Pb = 1.5 µg/g and Cd = 1.0 µg/g), suggesting significant pollution from the waste outlets near Høvringen and Lade.