Variability of trophic magnification factors as an effect of estimated trophic position: Application of compound-specific nitrogen isotope analysis of amino acids

• Published in: Environment international 2020-02, Vol.135, p.105361, Article 105361
• Main Authors: Won, Eun-Ji, Choi, Bohyung, Lee, Chang Hwa, Hong, Seongjin, Lee, Jong-Hyeon, Shin, Kyung-Hoon
• Format: Article
• Language: English
• Subjects: Compound-specific isotope analysis (CSIA); Food web; Trophic magnification factor (TMF); Trophic position
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2019.105361

[Display omitted] •Compound specific isotope analysis of amino acids is remarkable for calculating trophic position.•Trophic positions of fish were compared based on the δ15N of bulk and amino acids.•The concentrations of PCB, PBDE and OCPs in fish were increased with trophic position in Masan bay.•Trophic magnification factors are governed by trophic position. The trophic magnification of persistent organic pollutants (POPs), which is the relationship between POP concentration and the trophic position (TPs) of an organism, is considered an important factor for prioritizing chemicals of concern in the environment. Organismal TPs are typically based on nitrogen isotope ratios of bulk tissue (δ15Nbulk). In this study, nitrogen isotope ratios of amino acids (δ15NAAs), a more precise approach for TP estimation (TPAAs), was applied and compared with estimations of TP based on δ15Nbulk (TPbulk) in marine organisms living in Masan Bay, South Korea. Compound-specific isotope analysis of the amino acids (CSIA-AAs) in fish samples allows us to calculate robust TPs by correcting the variation in baseline isotope values with use of the δ15Nbulk technique. In a benthic food chain, this approach reveals more significant magnification trends for POPs [polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs)] than those revealed by analysis of the relationship between TPbulk and POPs. The trophic magnification factors (TMF) associated with TPAAs were significant for some POPs, especially pp′-DDD and chlordane. The results presented in this study suggest that TP calculations based on δ15NAAs are an effective tool for characterizing trophic magnification trends related to the fates of various pollutants.