Study on the Biogeochemical Cycling Processes of Trace Metals in the Pacific Ocean Based on Multi-Element Analysis

Abstract

This study investigates the biogeochemical cycling of nine trace metals (Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb) across the Pacific Ocean, aiming to elucidate the processes that govern their distribution in seawater. By examining their vertical sectional distributions in the North and South Pacific, the Bering Sea, and the Sea of Japan, the study evaluates how terrestrial and anthropogenic inputs influence marine environments. Results show that, in mid- to deep water layers, nutrient-type elements (Ni, Cu, Zn, Cd) are controlled not only by water circulation and biogeochemical cycling but also by scavenging. Ratios of nutrient-type elements to phosphate and apparent oxygen utilization indicate that scavenging significantly affects their distribution. Furthermore, the horizontal distribution of trace metals in deep layers highlights the influence of sediment-water exchange on the seawater composition.