Dissolved zinc and its speciation in the northeastern Indian Ocean and Andaman Sea

Abstract

Zinc (Zn) is an essential micronutrient for bacteria and phytoplankton in the ocean. Reportedly, organic complexes of dissolved zinc in surface waters account for about 98% of the total dissolved zinc. The organic complexation reduces the bioavailable zinc, the free metal ion (Zn²⁺), to a level as low as 1pM. Therefore, Zn speciation is important to understand biogeochemical cycles of Zn in the ocean. In this study, by using cathodic strriping voltammetry (CSV), distributions of dissolved Zn and its speciation were determined to investigate the geochemical processes of Zn in the northeastern Indian Ocean and Andaman Sea.