Glucose-6-phosphate dehydrogenase and lactate dehydrogenase in the green-lipped mussel (Perna viridis): Possible biomarkers for hypoxia in the marine environment

Green-lipped mussels (Perna viridis) were collected from a well-oxygenated site in Hong Kong and maintained in situ at this and three other sites with different dissolved oxygen (DO) regimes. The transplanted mussels were retrieved after a 4-week field exposure. An estimation of the activities of glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the adductor muscles of the mussels showed a significant, negative correlation with ambient DO levels at the study sites, suggesting that an increase in activities of these two enzymes may be related to the lowering of ambient oxygen levels. The possibility of using G6PDH and LDH as quantitative biomarkers for hypoxia in the marine environment is discussed.