title: Biomagnification of trace elements in the aquatic food web in the Mekong Delta, South Vietnam using stable carbon and nitrogen isotope analysis.
abstract: In the present study, we report the concentrations of 21 trace elements (V, Cr, Mn, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi), as well as the results of the analysis of stable carbon and nitrogen isotopes, of the various biota that make up the food web in the main stream of the Mekong Delta near Can Tho, South Vietnam. A significant trophic level-dependent increase was found in concentrations of Se, Rb, and Hg with increasing delta(15)N, indicating that an overall biomagnification of these elements occurred. However, the increase of Hg concentration per trophic level was lower than in previous studies. In contrast, the concentration of Mn showed an opposite trend in the food web of the Mekong Delta. In addition to these overall trends, the present study revealed that the biomagnification profiles of trace metals differ between crustaceans and fishes; concentrations of Mn, Cu, Zn, As, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, and Pb were significantly higher in crustaceans, whereas fishes showed higher concentrations of Cr, Rb, and Hg (trophic level determined by delta(15)N). The differences in the biomagnification profile between the major taxa might be attributed to differences in metal accumulation and in detoxification abilities such as possessing a metal-binding protein, e.g., metallothionein (MT).
authors.affiliation: Department of Life Environment Conservation, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, 790-8566, Japan.
authors.forename: Tokutaka
authors.initials: T
authors.lastname: Ikemoto
authors.forename: Nguyen Phuc Cam
authors.initials: NP
authors.lastname: Tu
authors.forename: Noboru
authors.initials: N
authors.lastname: Okuda
authors.forename: Akihisa
authors.initials: A
authors.lastname: Iwata
authors.forename: Koji
authors.initials: K
authors.lastname: Omori
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Tanabe
authors.forename: Bui Cach
authors.initials: BC
authors.lastname: Tuyen
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takeuchi
mesh_terms: D000818:Animals; D001151:Arsenic / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism*; D003445:Crustacea / Q000378:metabolism; D004784:Environmental Monitoring; D005399:Fishes / Q000378:metabolism; D020387:Food Chain; D008670:Metals / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000378:metabolism*; D010839:Phytoplankton / Q000378:metabolism; D012643:Selenium / Q000378:metabolism*; D014744:Vietnam; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D008670:Metals; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D012643:Selenium; D001151:Arsenic