The effect of anthropogenic activities has been studied in two stations, each in Palk Bay and Gulf of Mannar,
and compared with an offshore site in the former bay for one year on a monthly basis. The mean level of trace
metals (Cd, Cu, Pb and Zn) in sediment from polluted areas was 1.23 ppm, 5.42 ppm, 15.52 ppm and 7 ppm
respectively. The maximum Cd, Cu, Pb and Zn level in seawater from polluted areas were 1.11 ppb, 26.78
ppb, 21.35 ppb and 247.12 ppb respectively. The mean level of these metals in zooplankton and clam from
polluted areas were 1.12 ppm, 14.47 ppm, 24.03 ppm and 267.2 ppm respectively. Analysis of variance
(ANOVA) showed no significant difference in the trace metal levels in water, tissue and sediment between
polluted and reference station. The paper draws attention to the concentrations of trace metals in the marine
environment and biota of Palk Bay and Gulf of Mannar along with other hydrological parameters.

Trace metals, marine environment, hydrobiology, Palk Bay, Gulf of Mannar