Toxicological impact of Rare Earth Elements (REEs) to marine copepods Tigriopus fulvus

The increasing use in diverse technological applications linked to the world economy is leading to an increased presence of rare earth elements (REEs) in aquatic bodies. Relatively little is known about the influence and toxicity of REEs to marine biota. In the present study, the acute toxicity of Neodymium (Nd), Holmium (Ho ), Erbium (Er), Dysprosium (Dy), Scandium (Sc) and Yttrium (Y) to the copepod Tigriopus fulvus was evaluated by mortality, immobilization and naupliar development. The results obtained clearly demonstrated that the studied REEs severely affected T. fulvus following the dose-response trend. Neodynium exerted significantly higher toxicity than the other ones with median lethal dose concentration (LC50) of 1.06 mg/L and median immobilization dose (ImC50) of 0.18 mg/L. All tested REEs determined a significant slowdown of naupliar development with a percentage reduction of moults number of about 50% compared to the control at 0.8 mg/L.