Toxicity and transfer of metal oxide nanoparticles from microalgae to sea urchin larvae

Abstract

Nanoparticles (NPs) contained in commercial products are released and enter into the aquatic ecosystem, posing serious possible risks to the environment and affecting the food chain. Therefore, investigating the potential toxicity of NPs on aquatic organisms has become an important issue. This study assessed the toxicity and trophic transfer of metal oxide NPs from marine microalgae (Cricosphaera elongata) to the larvae of the sea urchin Paracentrotus lividus. Larvae (24 h old) were fed on 2000 cell mL⁻¹ 48 h of microalgae contaminated with 5 mg L⁻¹ of several metal oxide NPs (SiO₂, SnO₂, CeO₂, Fe₃O₄) for 15 days. Larval viability and development were monitored from the 4-arm stage to the 8-arm pluteus stage. A significant decrease in survival was observed in larvae fed with microalgae exposed to SiO₂ and CeO₂ NPs. Abnormal development, characterised by skeletal degeneration and altered rudiment growth, was observed in all larvae fed with contaminated NP algae. Our findings revealed that SiO₂ and CeO₂ NPs exerted a toxic effect in the trophic interaction analysed, by reducing sea urchin larval viability, and all metal oxide NPs induced toxicological effects. In conclusion, metal oxide NPs may enter the food chain and become bioavailable for marine organisms, affecting their development.

Keywords:

• echinoderms
• food
• microalgae
• nanoparticles
• Paracentrotus lividus
• sea urchin
• toxicity

Acknowledgements

The authors would like to thank INESE ‘Impact of NPs on Environmental Sustainability and Ecotoxicity’ project (2010–2013) supported by IIT (Italian Institute of Technology, Genova, IT).