Impacts of tropical cyclones and anthropogenic activities on marine vanadium: A unique perspective from high resolution Porites coral record

As a typical contaminant in fossil fuels, vanadium has undergone dramatically increase due to the impacts from human activities. The excessive anthropogenic vanadium emissions have altered natural geochemical processes. However, research on vanadium geochemistry in the ocean, which is the major sink for vanadium mobilized on land, has lagged much behind relative to those of other contaminants. Here we reconstruct historical patterns of vanadium in surface seawater utilizing a high-resolution temporal record (1984–2015 CE) of geochemical proxies (vanadium/calcium (V/Ca), δ 18 O, δ 13 C, etc.) in a Porites coral colony from an offshore non-estuarine island in the northern South China Sea (SCS). We find a close association between the surface winds and the temporal patterns of coral V/Ca ratios, revealing great potential for documenting prehistoric changes in tropical cyclones. Moreover, the coral V/Ca record remarkably captured the temporal patterns of anthropogenic activities, offering a valuable and novel tool for testing the efficacy of specific legislation on pollution prevention. Combined with the other reported coral vanadium data, we recovered the historical changes in vanadium emissions in the northern SCS and identified that changing industrial practices should be responsible for the differences in anthropogenic vanadium emissions at each stage. Our results demonstrated that the coral V/Ca ratio at a high temporal resolution has great potential as a new and direct geochemical proxy for tropical cyclones after removing artificial disturbances in the ocean.