A screening study of relationships among concentrations of algal toxins, PFAS, thiamine deficiency and biomarkers in the European flounder from the southern Baltic Sea

In the disturbed Baltic Sea ecosystem, several animal species display failing health related to exposure to toxic compounds, reduced energy metabolism and immune system disorders. In order to investigate possible associations between fish health and exposure to chemicals affecting the energy metabolism and immune defence, the levels of algal toxins (bromophenols, hydroxylated polybrominated diphenyl ethers and nodularin), perfluorinated alkyl substances (PFAS) and thiamine (vitamin B1) were determined in European flounder (Platichthys flesus). Several biomarkers indicating health status were examined in the fish, including ethoxyresorufin-O-deethylase (EROD), and activities of glutathione reductase, glutathione S-transferase and catalase, in addition to a large set of blood variables. The fish were collected from Hanobukten in the south-western parts of the Baltic Sea in late August 2018. Regression analyses of algal toxins, PFAS and thiamine concentration displayed several significant associations with biomarkers associated with detoxification and liver function, immune system function and blood status of the fish. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

In the disturbed Baltic Sea ecosystem, the health of several animal species is negatively affected by exposure to toxic compounds, reduced energy metabolism, and immune system disorders. A study investigated the association between fish health and exposure to chemicals affecting energy metabolism and immune defense in European flounder. The results showed significant associations between algal toxins, perfluorinated alkyl substances (PFAS), and thiamine concentration with biomarkers related to detoxification, liver function, immune system function, and blood status of the fish.