PCBs contamination does not alter aerobic metabolism and tolerance to hypoxia of juvenile sole (Solea solea L. 1758)

Coastal habitats play a major role as nurseries for many fish species; however, they are also submitted to pollutants and oxygen fluctuations. Fry's concept of metabolic scope for activity was used to evaluate the effect of polychlorinated biphenyls (PCBs) on the aerobic metabolism in juvenile common sole (0–1 year old). Aerobic metabolic scope (AMS) in control and PCB-contaminated fish via food pathway was determined using respirometry techniques. Furthermore, the hypoxia tolerance in control and PCB-contaminated fish was evaluated by assessing their critical oxygen concentration (O2crit). Our results showed that while PCB-contaminated fish were able to maintain a constant AMS and O2crit, PCBs tend to affect their aerobic metabolism by acting on maximal oxygen consumption (MO2max) in hypoxia and standard metabolic rate, but only at the highest PCB concentration between 30 and 60 days of exposure. In conclusion, we can hypothetise that the tested PCB-exposures may not impair the tolerance to hypoxia and the survival of common sole in their natural environment.

► Coastal habitats are often submitted to pollutants and oxygen fluctuations. ► We measured aerobic metabolic scope (AMS) in control and PCB-contaminated fish in both normoxic and hypoxic conditions, using respirometry techniques. ► We showed that PCB-contaminated fish were able to maintain constant their AMS and critical oxygen saturation. ► We hypothesised that exposure to PCBs may not impair the tolerance to hypoxia and the survival of common sole in their natural environment.