Tebuconazole bioconcentration in European Eels (Anguilla Anguilla): the role of pollutant cocktails

European eel (Anguilla anguilla) populations are in decline across Europe, with organic pollutants (OPs) identified as one of the contributing factors. In the Albufera of Valencia, a critical feeding and maturation habitat for this species, a significant number of OPs have been identified, with tebuconazole exhibiting the highest concentrations among the compounds detected. This study aimed to assess the bioconcentration of tebuconazole in European eels following waterborne exposure, both alone and in combination with other commonly detected OPs. Eels were exposed under controlled laboratory conditions to environmentally relevant concentrations of tebuconazole and other OPs, and tissue samples were analysed to determine their bioconcentration. Statistically significant differences in tebuconazole accumulation were observed during the exposure phase, with notably higher concentrations in eel tissues when the compound was administered alone, compared to co-exposure with other OPs. These results suggest that the presence of pollutant cocktails may alter the bioconcentration of individual substances, potentially through interactions affecting absorption, distribution, or metabolism. This study highlights the importance of considering the complex nature of contaminants mixtures in natural habitats. Understanding how these interactions affect species like the European eel is crucial for protecting vulnerable populations, and ensuring ecosystem and food safety.