Qinqin Chen , Qingru Wu, Yuying Cui, Shuxiao Wang

Global ecosystems face mercury contamination, yet long-term data is scarce, hindering understanding of ecosystem responses to atmospheric Hg input changes. To bridge data gap and assess ecosystem responses, we compiled and compared a mercury accumulation database from peat, lake, ice, and marine deposits worldwide with atmospheric mercury deposition modeled by GEOS-Chem, focusing on trends, magnitudes, spatial-temporal distributions, and impact factors. The mercury fluxes in all four deposits showed a five to nine-fold increase over 1700-2012, with lake and peat mercury fluxes generally mirrored atmospheric deposition trends. Significant decreases in lake and peat mercury fluxes post-1950 in Europe evidenced effective environmental policies, whereas rises in East Asia, Africa, and Oceania highlighted coal-use impacts, inter alia. Conversely, mercury fluxes in marine and high-altitude ecosystems did not align well with atmospheric deposition, emphasising natural influences over anthropogenic impacts. Our study underscores the importance of these key regions and ecosystems for future mercury management.