Mangrove ecosystems provide ideal habitats for many marine organisms, but few studies have been conducted
on the possible impact of heavy metals on these fragile inter-tidal estuarine wetlands. This study aimed to investigate
heavy metal contamination in the sediments and zoobenthos in different mangrove ecosystems of southern
China and to evaluate potential ecology risks of heavy metals in the sediment of mangrove ecosystems.
Significant differences among different geographical regions were observed for the contents of Cu, Zn, As, Cd,
and Pb in the sediment, while no significant differences were found among different vegetations. Except for
Pb, the heavymetal contents in two species of crabs (Perisesarma bidens and Parasesarma plicata) inthe Aegiceras
corniculatumforestwere lower than those in Bruguiera gymnorrhiza forest or Pagatpat forest. The sediment in the
most mangrove ecosystems of China posed considerable or moderate ecological risk. Correlation analysis and
principal component analysis (PCA) revealed that Cr, Cu, Zn and Pb were mainly derived from anthropogenic
activities such as industrial effluents and domestic sewage.