The usefulness of seaweeds as an indicator of metals in the Kudankulam coastal waters is highlighted in this study. Twenty five seaweed species were collected from the intertidal region of the Kudankulam coast. The collected samples were analysed for Cr, Mn, Fe, Co,Ni, Cu, Zn, Cd and Pb in Atomic Absorption Spectrophotometer (AAS). The concentration of heavy metals in various Phaeophyta species was found to be relatively higher compared to those in the other two algal groups (Chlorophyta and Rhodophyta). The results showed that the concentration of Fe and Mn in most of the seaweeds were found to be higher but widely fluctuating. Inter-elemental relationship was also established. Significant linear correlation was observed between 36 pairs of metals. The metal contents of all the algae were subjected to Metal Pollution Index (MPI) analysis for comparing total metal load between species. The highest MPI was found in Hypnea sp. Valaniopsis pachynema, Padina pavonica and Hypnea sp. accumulate most of the metals in a higher level. Because of the higher concentration of most of the metals, these species could be used as indicators of metal pollution. This study was carried out in Kudankulam coast, 25 km northeast of Kanyakumari where a mega nuclear power station is under construction. Since radio nuclides behave similar to stable nuclei, the present study assumes greater importance for Kudankulam coast. This study provides baseline data for heavy metals of Kudankulam marine algae and for assessing if there is any change in future in the environment.

Heavy metals, seaweeds, Metal Pollution Index