Earth is thought to have entered a new geological epoch, the Anthropocene, as humans have become the dominant force in contemporary environmental changes (Waters et al., 2016). In particular, huge amounts of toxic chemicals from industry, agriculture and urbanization have been widely and rapidly introduced into the ocean since the 1950s (Steffen et al., 2015). Among these chemicals, pollution of heavy metals (e.g., Pb, Cd, Cr, Cu, Hg, and Zn) have attracted great attention because they are persistent and biologically active, and readily assimilated by marine biota and by humans (Kalisinska, 2019). Shallow-water corals are widely distributed in the subtropical and tropical ocean and ambient seawater can be transported to the calcifying site where the marine metals substitute for Ca in the coral skeleton during skeletal calcification (Gaetani & Cohen, 2006). Thus, the seasonally and annually banded corals are unique archives of trace metals' chemistry in the marine environment, providing centennial-scale records at high (annual-seasonal) resolution (Saha et al., 2016;Sun et al., 2016;Weerabaddana et al., 2021). These records are valuable for our understanding of human impacts on the natural cycles of metals and for assessing global efforts to reduce anthropogenic metal emissions.However, metal concentrations in corals alone cannot provide direct provide diagnostic information on historical sources or migration processes of heavy metals. The heavy metal sources are diverse and their migration processes are complex. In addition to direct anthropogenic inputs from metal mining, smelting, domestic and industrial sewage (Araújo et al., 2019;Liao et al., 2021), natural rock weathering and soil erosion can also introduce large amounts of heavy metals to the surface ocean (Chester & Jickells, 2012). Several studies have successfully used

Soil erosion in East and Southeast Asia is believed to have increased significantly since the regional economic boom of the 1970s–1980s. However, limited records of soil erosion make it difficult to understand and indeed verify such changes. Here we present two new monthly resolved Ba/Ca records from Porites coral skeletons from southern Taiwan and central Vietnam, supplemented with some sporadic monthly and annually resolved coral δ138/134Ba data. Our records span the 1980s to the 2000s and suggest that there were intervals of elevated seawater Ba concentrations (Basw) during the intervals 1987–1995 in southern Taiwan and 1992–2001 in central Vietnam. In combination with evidence for insignificant changes in regional seawater δ138/134Ba values, model simulations, and other published coral Ba/Ca records from Lanyu (offshore southeast Taiwan) and Hainan, we infer that the intervals of high Basw values are linked to soil erosion associated with land use changes and socioeconomic developments. The increased sediment loads are also likely responsible for the recent degradation of regional coral reefs. Our study provides new insights into regional soil erosion histories, which may prove useful for guiding soil conservation and sustainable land management.