Heavy metal concentrations in Nerita lineata: the potential as a biomonitor for heavy metal bioavailability and contamination in the tropical intertidal area

The concentrations of Cd, Cu, Pb, Zn, Ni and Fe were determined in the gastropod Nerita lineata collected from 15 sites in the west intertidal area of Peninsular Malaysia (shell length 11.5–33.8 mm). The results of the present study showed that metal concentrations in the shells, opercula and soft tissues of N. lineata were distributed differently at different sampling sites. The mean concentrations (μg/g dry weight) of Cd, Cu, Fe, Ni, Pb and Zn in the samples were 2.99, 6.38, 35.05, 23.34, 48.22 and 16.59 in the opercula, 3.15, 5.59, 49.78, 24.18, 48.86 and 7.86 in the shells and 1.03, 2.65, 566.63, 5.85, 92.72 and 92.75 in the soft tissues. All the populations of N. lineata showed similar trends in the accumulation of Cd, Ni and Pb which decreased as follows: shell > operculum > soft tissue, Cu and Zn deceased in the order: soft tissue > operculum > shell and Fe in the order: soft tissue >shell > operculum. In general, higher concentrations of metals were recorded in samples collected from the stations closed to the anthropogenic sites. In particular, snail samples collected from KSAyam accumulated higher Pb concentrations when compared to other sites in the opercula, shells and soft tissues. This may indicate high bioavailability and contamination via Pb of the study site. The snail N. lineata is therefore suggested as a potential biomonitor of bioavailability and contamination of heavy metal in general and Pb in particular for the tropical intertidal area of Peninsular Malaysia.