Open AccessDissolved elements reactivity in water column directly influences their chemical and toxic behavior, and in their bioavailability, therefore, in their environmental profile in estuarine systems, important for their great biological productivity and location in zones with potential anthropic impacts. In this context, this study evaluated the behavior of metals (Ba, Fe, Li, Mn and Zn) and the semimetal B throughout the estuarine mixture in the Estuarine System of Cananéia-Iguape. It was observed that B and Li presented conservative behavior as they are not reactive, Ba, Fe and Zn presented not conservative behavior with removal in low salinities, and Mn presented mixed behavior, with addition in low salinities and approximately conservative behavior in high salinities.