The Beung Boraphet tributaries were contaminated with heavy
metals such as Fe and Cu. In addition, the snail P. canaliculata and aquatic plant, I. aquatica
both contained high levels of metals and biomagnified some metals such as Mn and Zn in their
tissues. Hence, both P. canaliculata and I. aquatica could be used as biomonitors of sedimentary
metal contamination because they possess several attributes of a biomonitor (Phillips, 1990).
Both were abundant, tolerant to metals, dominant in metal-contaminated water. Their tissue
concentration of metals reflected the levels of sedimentary
contamination by these metals (Deng et al., 2008).