Maternal transfer of emerging brominated and chlorinated flame retardants in European eels

• Main Authors: Roxana Suehring, Marko Freese, Mandy Schneider, Sophia Schubert, Jan-Dag Pohlmann, Mehran Alaee, Hendrik Wolschke, Reinhold Hanel, Ralf Ebinghaus, Lasse Marohn
• Format: Report
• Language: unknown
• Published: 2023
• Subjects: Marine ecology (including marine ichthyology); Ecology; n.e.c; Animal physiological ecology; European eel; Anguilla anguilla; endangered species; brominated and chlorinated flame retardants
• Online Access: https://doi.org/10.32920/21977384.v1; https://figshare.com/articles/preprint/Maternal_transfer_of_emerging_brominated_and_chlorinated_flame_retardants_in_European_eels/21977384

The European eel (Anguilla anguilla) is regarded as a critically endangered species. Scientists are in agreement that the “quality of spawners” is a vital factor for the survival of the species. This quality can be impaired by parasites, disease and pollution. Especially endocrine disrupting organic chemicals pose a potential threat to reproduction and development of offspring. To our knowledge, the findings in this publication for the first time describe maternal transfer of contaminants in eels. We analysed the concentrations of in total 53 polybrominated diphenyl ethers (PBDEs) and their halogenated substitutes in muscle, gonads and eggs of artificially matured European eels and in muscle and gonads of untreated European eels that were used for comparison. We found evidence that persistent organic pollutants such as PBDEs, as well as their brominated and chlorinated substitutes are redistributed from muscle tissue to gonads and eggs. Concentrations ranged from 0.001 ng g-1 ww for sum Dechlorane metabolites (DPMA, aCL10DP, aCl11DP) to 2.1 ng g-1 ww for TBA in eggs, 0.001 ng g-1 ww for Dechlorane metabolites to 9.4 ng g-1 ww for TBA in gonads and 0.002 ng g-1 ww for Dechlorane metabolites to 54 ng g-1 ww for TBA in muscle tissue. Average egg muscle ratios (EMRs) for compounds detectable in artificially matured eels from both Schlei Fjord and Ems River ranged from 0.01 for Dechlorane 602 (DDC-DBF) to 10.4 for PBEB. Strong correlations were found between flame retardant concentrations and lipid content in the analysed tissue types, as well as transfer rates and octanol-water partitioning coefficient, indicating that these parameters were the driving factors for the observed maternal transfer. Furthermore, indications were found, that TBP-DBPE, TBP-AE, BATE and TBA have a significant uptake from the surrounding water, rather than just food and might additionally be formed by metabolism or biotransformation processes. Dechloranes seem to be of increasing relevance as contaminants in eels and are transferred to ...