Stable Isotopes (δ13C and δ15N) and Trace Elements of Invertebrates and Fish from the Coastal Waters of Ha Tinh Province, Central Vietnam

Abstract

Stable isotope signatures (δ¹³C, δ¹⁵N) and trace elements (TEs) were analyzed from invertebrates and fish to assess food web structure and the biomagnification or biodilution of Cu, Pb, Cd, Zn, Mn, Cr, Hg and As in coastal waters of Ha Tinh Province, Central Vietnam. δ¹³C and δ¹⁵N values of purported food sources (sediments, phytoplankton, macroalgae, and zooplankton) ranged from -21.24 ± 0.39‰ to -16.72 ± 1.02‰ and from 3.02 ± 0.70‰ to 7.30 ± 0.42‰, respectively. The δ¹³C and δ¹⁵N values in invertebrates and fish ranged from -19.75 ± 0.10‰ to -18.68 ± 0.40‰, and from 7.02 ± 1.21‰ to 9.10 ± 0.29‰. The δ¹⁵N values showed that the food web structure could be divided into four trophic levels. The benthic invertebrates had significantly higher concentrations of Cu, Pb, Zn, Cd and As. Hg concentrations tended to accumulate higher in the crabs and fish. The biodilution of Pb, Cd, Zn, Cr was observed throughout the food web, whereas biomagnification was observed for Cr, Mn, and As in bivalves; Cd and Zn in gastropods; Pb, Cd, Zn, and As in crabs; Cd in prawns and Hg in fish.