Distribution, bioaccumulation, trophic transfer and risk assessment of trace elements in fish from a typical shallow outflow lake basin, China

Fish are important food sources for humans, and the availability of appropriate amount of trace elements (TEs) plays a crucial role in fish growth. Currently, due to large volumes of sewage discharge, high levels of certain elements are present in aquatic environments, and these elements accumulate in fish and potentially affect human health. In this study, the distribution and bioaccumulation capacity of trace elements in six dominant fish species from Chaohu Lake (China) were analyzed. The results showed that the bioaccumulation capacity of fish for Zn was greater than other TEs. And the source of the TEs in the fish were explored along with the concentration of the TEs in the aquatic environment, which indicated that TEs in fish were mainly obtained through ingestion and indirectly affected by the industrial activities in the basin. Additionally, stable carbon and nitrogen isotopes were used to classify the trophic levels and explore the biological magnification of TEs of the fish. It was found that Sb and Sr showed biomagnification with the increase of trophic level of fish. Based on the above analyses, the environmental biogeochemical cycle model of TEs in the lake was distinguished and established, which can offer valuable insights for sustainable fishery management in the downstream Yangtze River Delta ecosystem.