A study conducted by Professor Tseng’s team, published in Environmental Research in 2025, analyzed total mercury (THg) concentrations and stable isotope compositions in marine pelagic and mesopelagic fish species collected off Taiwan. The results showed that THg concentrations were significantly positively correlated with body length in most species, reflecting size- and age-dependent bioaccumulation effects. In contrast, cephalopods (e.g., squid) and cutlassfish exhibited weaker trends, likely due to their rapid growth and shorter lifespans. THg concentrations also increased with δ15N values, supporting trophic-level biomagnification, and species with higher δ15N were generally associated with deeper habitats, suggesting elevated methylmercury concentrations in deeper environments. Biomagnification slopes and trophic magnification factors (TMF) were slightly higher in the western North Pacific (WNPO) than in the eastern North Pacific (ENPO), which may be related to stronger pollution pressure and more efficient food-web transfer. Strong THg–δ15N correlations (R² ≈ 0.8) across both regions indicate that mercury accumulation is jointly controlled by species-specific traits and regional oceanographic conditions. Overall, this study advances understanding of marine Hg contamination and food-web transfer processes, highlighting the complexity of Hg bioaccumulation driven by multiple ecological factors. The findings emphasize the need for continued monitoring of Hg sources to mitigate pollution risks and provide valuable insights for fisheries management and seafood safety assessments.
Web link: https://www.sciencedirect.com/science/article/pii/S0013935125025812
Lee Deborah F.-J., J. Tseng, Z.-Y. Huang, H. Tseng, P.-L. Wang, C.-M. Tseng* (2025) Mercury Bioaccumulation and Trophic Dynamics in Marine Fishes off Taiwan Revealed by Stable Isotopes. Environmental Research, 289, 123328, https://doi.org/10.1016/j.envres.2025
Figure 1: Conceptual diagram illustrating the processes that shape the alkenone sedimentary record.
