2024 Volume 33 Issue 1-2 Pages 17-30
In the ocean, trace metals, such as nickel, copper, and zinc, are present in concentrations on the order of pmol/kg～nmol/kg. These metals are essential nutrients and toxins for marine organisms. Herein, the sources and biogeochemical cycles of trace metals in the ocean are elucidated based on their isotope ratios. (i) An analytical method for determining the isotope ratios of dissolved nickel, copper, and zinc in seawater is developed. This method can be used to simultaneously analyze the isotope ratios of nickel, copper, and zinc in seawater, enabling the efficient observation of isotope ratio distributions of trace metals. (ii) The concentrations and isotopic distributions of dissolved copper in the Indian and Pacific Oceans are uncovered, providing insight into the biogeochemical cycle of copper in the oceans. (iii) The isotopic distributions of dissolved nickel, copper, and zinc in the East China Sea are determined, and the transport process of trace metals from the land to the surface layer of the East China Sea is elucidated. (iv) Moreover, particulate trace metals are analyzed. The isotope ratios of nickel and copper in sinking particles in the South China Sea are investigated to potentially determine the sources of these particulate trace metals.
