Study on accumulation potential of zinc oxide nanoparticles in Artemia and its trophic transfer to Zebrafish (Danio rerio)

Although nanomaterials have broad applications in many fields including aquaculture, their release into the environment has raised some concerns in recent years. This study was conducted to investigate the possibility of enriching Artemia with zinc oxide nanoparticles (ZnO-NPs) for possible use in aquaculture on the one hand, and, on the other hand, to investigate the transfer of this material through the food chain and its accumulation in the body of zebrafish as an aquatic model. In order to evaluate the absorption and excretion of ZnO-NPs in Artemia, nauplii were exposed to concentrations of 1, 10 and 100 mg/L ZnO-NPs suspension for 24 hours and then placed in the nanoparticles-free water for another 24 hours. The zebrafish were then fed with ZnO-NPs enriched nauplii for 21 days, followed by feeding on nanoparticles-free nauplii for 7 days to determine trophic transfer as well as excretion of nanoparticles from the fish body. The accumulated zinc over the periods of absorption and excretion in nauplii and fish were measured using atomic absorption spectrophotometer. The results showed that Artemia nauplii had high potential for accumulation of ZnO-NPs, while accumulated zinc had high potential for transfer to fish. Based on the results, Artemia can be enriched with ZnO-NPs so that the needs of fish to zinc can be met. However, the risk of nanomaterials release into the aquatic ecosystems and their trophic transfer along the food chain should be considered