Lethal and sublethal effects of polybrominated diphenyl ethers (PBDEs) for turbot (Psetta maxima) early life stage (ELS)

A new toxic menace, polybrominated diphenyl ethers (PBDEs), is being detected in the aquatic environment all over the world. The environmental presence of PBDEs and its entry into the environment as BDE-47 and -99 make quality aquatic toxicity data necessary to assess the aquatic hazard risk of PBDs. This study examines the effects of three PBDE-47 and -99 on embryo and larval stages of the marine flatfish turbot (Psetta maxima). The acute toxicity of the three PBDEs was examined and NOEC, LOEC, LC10 and LC50 were calculated. All tested compounds caused lethal as well as nonlethal malformations during embryo development. The effects of PBDEs in the different life stages of turbot were analysed. PBDEs seemed to be teratogenic at concentrations higher than 8.14 and 16.12 μgL for BDE-47 and -99 respectively, leading to prolonged delays in embryo development and consequent death (at 48 h), as well as severe malformations and mortality of larvae. PBDEs showed a higher acute toxicity for embryo-larvae (LC50 for lethal endpoints to embryos 27.35 μg BDE-47 L -1 and 38.28 μg BDE-99 L, and 14.13 and 29.64 μg L for BDE-47 and -99, respectively for larvae). Generally, the BDE-47 seemed to cause adverse effects at comparatively low dose rates, whereas much higher doses were needed to cause the same effects with BDE-99. The results of the present study show that the acute toxicity of PBDEs decreases as the degree of bromination increases, since the order of toxicity was BDE47˃ BDE-99. The major isomers also exhibited a clear toxic potential for turbot ELS although at high concentrations, above solubility saturation, pointing at particulate matter as the main via of uptake for those hydrophobic molecules.