© The Author(s) 2017. The increasing usage of nanoparticles has caused their considerable release into the aquatic environment. Meanwhile, anthropogenic CO 2 emissions have caused a reduction of seawater pH. However, their combined effects on marine species have not been experimentally evaluated. This study estimated the physiological toxicity of nano-TiO 2 in the mussel Mytilus coruscus under high pCO 2 (2500-2600 μatm). We found that respiration rate (RR), food absorption efficiency (AE), clearance rate (CR), scope for growth (SFG) and O:N ratio were significantly reduced by nano-TiO 2 , whereas faecal organic weight rate and ammonia excretion rate (ER) were increased under nano-TiO 2 conditions. High pCO 2 exerted lower effects on CR, RR, ER and O:N ratio than nano-TiO 2 . Despite this, significant interactions of CO 2 -induced pH change and nano-TiO 2 were found in RR, ER and O:N ratio. PCA showed close relationships among most test parameters, i.e., RR, CR, AE, SFG and O:N ratio. The normal physiological responses were strongly correlated to a positive SFG with normal pH and no/low nano-TiO 2 conditions. Our results indicate that physiological functions of M. coruscus are more severely impaired by the combination of nano-TiO 2 and high pCO 2 .
Hu, M., Lin, D., Shang, Y., Hu, Y., Lu, W., Huang, X., … Wang, Y. (2017). CO 2 -induced pH reduction increases physiological toxicity of nano-TiO 2 in the mussel Mytilus coruscus. Scientific Reports, 7. https://doi.org/10.1038/srep40015