Biomagnification Profiles of Trace Elements through the Food Web of an Integrated Shrimp Mangrove Farm in Ba Ria Vung Tau, South Vietnam
Nguyen Phuc Cam Tu, Nguyen Ngoc Ha, Hiroaki Matsuo, Bui Cach Tuyen, Shinsuke Tanabe and Ichiro Takeuchi
DOI : 10.3844/ajessp.2012.117.129
American Journal of Environmental Sciences
Volume 8, Issue 2
Problem statement: Ba Ria Vung Tau (BRVT), a Vietnamese province with one of the fastest growing economies in the country, faces significant environmental challenges, including increased contamination of rivers and estuaries with urban and industrial wastes. Approach: Concentrations of 23 trace elements and stable isotope ratios (δ13C and δ15N) were analyzed in suspended particulate matter, one species of peanut worm, one species of octopus, six species of crustaceans and 13 species of fish collected from an integrated shrimp mangrove farm in the BRVT. Results: Concentrations of Cu, Zn, Se, Mo, Ag, Cd, Sb and Bi in octopus, Mn, Sr and Ba in crustaceans and Hg in fish were the highest among organisms analyzed. Using δ15N values to identify trophic positions, we found that Zn, Se and Hg biomagnified through the food web. The slope for Hg (0.048) was remarkably lower than those reported for other aquatic food webs. In contrast, the concentrations of most trace elements followed reverse trends (i.e., decreasing concentrations with increasing trophic level). Trace element concentrations we measured in organisms were within safe levels for human consumption according to criteria established by the Ministry of Agriculture, Fisheries and Food (MAFF) in the UK. However, concentrations of Cu in black tiger shrimps and octopus and Zn in Commerson's glassy fish were higher than the MAFF guidelines. Conclusion: The results of this study highlight the usefulness of δ13C and δ15N as a tool not only for elucidating the trophic position of biota, but also for tracing contaminants within food webs.
© 2012 Nguyen Phuc Cam Tu, Nguyen Ngoc Ha, Hiroaki Matsuo, Bui Cach Tuyen, Shinsuke Tanabe and Ichiro Takeuchi. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.