Higher Fluctuating Asymmetry: Indication of Stress on Anadara trapezia Associated with Contaminated Seagrass

Seagrasses are marine angiosperms that colonize near-shore environments. Concern has arisen over increasing concentrations of heavy metals in these systems resulting from industrial and urban development due to the ability of seagrass to accumulate trace metals from the environment without showing any impact on their productivity. This may pose a threat to a coastal community because the polluted seagrass will then provide a source of contamination to seagrass consumers. The main aim of this study was to determine whether there was any detectable effect of heavy metal pollution in seagrass on associated fauna. Fluctuating asymmetry of shell structure of a bivalve, Anadara trapezia, were employed as biomarkers for this environmental study. The result from this study revealed that A. trapezia showed distinct morphological characters and high shell asymmetry in the polluted location. Thus, A. trapezia associated with seagrass may be responsive to heavy metal stress and possibly a good indicator of heavy metal pollution in this system. The present study discusses the possibility of using a more cost-effective biomarker to define areas of heavy metal pollution.