Biogeochemical Implications of Dissolved Trace Metal Concentration and Distribution in the South China Sea, Area 1: Gulf of Thailand and East Coast of Peninsular Malaysia

Abstract

Dissolved cadmium, copper, iron, lead and nickel in seawater at different depths were analyzed using the cobalt-APDC coprecipitation technique. The concentrations found were low and within the range found in natural seawater elsewhere. Terrestrial sources, especially near the head of the Gulf of Thailand and the Nakorn Sri Thammarat-Songkhla area on the Thai-Malay Peninsular, were clearly observed especially during the high runoff season. External input and horizontal dispersion dominated over internal recycling and removal in controlling concentration and distribution of iron and copper but it was the opposite for cadmium, nickle and lead where biological removal near surface and bottom regeneration might explain the nutrient type vertical profiles of these elements.