Distribution of heavy metals in seawater around the Shikoku Island

The distribution of trace metals (Al, Fe, Mn, Cd, Cu, Zr, and Y) dissolved in seawater around the Shikoku Island has been investigated, where salinity in the area ranged from 31 to Sampling method, sample storage, and analytical procedure were carefully examined to avoid contamination, Two methods of atomic absorption spectrometry and inductively coupled plasma atomic emission, spectrometry were employed for analyses of seawater samples and intercalibration of the analytical data. Almost all elements were found to show wide variations in concentration, i.e., higher concentration in the Inland Sea and lower concentration outside the Inland Sea. The latter concentrations were almost the same levels as those reported for surface water in the open ocean. The concentrations of Cu, Zn, Y. Cd, and Mn showed clearly negative correlations with salinity. This indicates that their distributions in the coastal area were regulated mainly by dilution with open seawater. The distributions of Al and Fe could be characterized by their lower concentrations in the surface water.