Antioxidant responses of the mussel Mytilus coruscus co-exposed to ocean acidification, hypoxia and warming

In the present study, the combined effects of pH, dissolved oxygen (DO) and temperature levels on the antioxidant responses of the mussel Mytilus coruscus were evaluated. Mussels were exposed to two pH (8.1, 7.7-acidification), two DO (6 mg L-1, 2 mg L-1-hypoxia) and two temperature levels (20 degrees C, 30 degrees C-warming) for 30 days. SOD, CAT, MDA, GPx, GSH, GST, TAOC, AKP, ACP, GPT, AST levels were measured in the gills of mussels. All tested biochemical parameters were altered by these three environmental stressors. Values for all the test parameters except GSH first increased and then decreased at various experimental treatments during days 15 and 30 as a result of acidification, hypoxia and warming. GSH content always increased with decreased pH, decreased DO and increased temperature. PCA showed a positive correlation among all the measured biochemical indexes. IBR results showed that M. coruscus were adversely affected by reduced pH, low DO and elevated temperature.

Automated summary

This study evaluated the combined effects of pH, dissolved oxygen (DO) and temperature on the antioxidant responses of Mytilus coruscus, finding that all tested biochemical parameters were affected by these environmental stressors. Some parameters showed an initial increase followed by a decrease over time, while GSH content increased with decreasing pH, DO and increasing temperature. The mussels were adversely impacted by reduced pH, low DO and elevated temperature, as shown by the Index of Biological Response (IBR) results.