New insight into biomagnification factor of mercury based on food web structure using stable isotopes of amino acids

• Published in: Water research (Oxford) 2023-10, Vol.245, p.120591-120591, Article 120591
• Main Authors: Kim, Dokyun, Won, Eun-Ji, Cho, Ha-Eun, Lee, Jonghyun, Shin, Kyung-Hoon
• Format: Article
• Language: English
• Subjects: Amino acid isotope; Biomagnification factor; Diet contribution; Mercury; Trophic position; Trophic transfer
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2023.120591

•An improved biomagnification factor (BMF) to clear understand fate of mercury.•Estimation of diet contribution with mathematical modeling using MixSIAR.•Useful tool of amino acids stable isotopes for identifying urban aquatic food web.•New BMF was normalized with both diet contribution and trophic position.•New BMF tended to be generally higher than the legacy TMF and BMF. Although many attempts have been carried out to elaborate trophic magnification factor (TMF) and biomagnification factor (BMF), such as normalizing the concentration of pollutants and averaging diet sources, the uncertainty of the indexes still need to be improved to assess the bioaccumulation of pollutants. This study first suggests an improved BMF (i.e., BMF′) applied to mercury bioaccumulation in freshwater fish from four sites before and after rainfall. The diet source and TP of each fish were identified using nitrogen stable isotope of amino acids (δ15NAAs) combined with bulk carbon stable isotope (δ13C). The BMF′ was calculated normalizing with TP and diet contributions derived from MixSIAR. The BMF′ values (1.3–27.2 and 1.2–27.8), which are representative of the entire food web, were generally higher than TMF (1.5–13.9 and 1.5–14.5) for both total mercury and methyl mercury, respectively. The BMF′ implying actual mercury transfer pathway is more reliable index than relatively underestimated TMF for risk assessment. The ecological approach for BMF calculations provides novel insight into the behavior and trophic transfer of pollutants like mercury. [Display omitted]