Large scale submarine groundwater discharge dominates nutrient inputs to China’s coast

作者：Tianyi Zhu, Shibin Zhao, Bochao Xu, Dongyan Liu, M. Bayani Cardenas, Huaming Yu, Yan Zhang, Xiaogang Chen, Kai Xiao, Lixin Yi, Hyung‐Mi Cho, Sumei Liu, Ziliang Zhang, Ergang Lian, William C. Burnett, Guangquan Chen, Zhigang Yu, Isaac R. Santos · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-58103-y · 被引用次数：42 · 研究领域：Groundwater and Isotope Geochemistry、Marine and coastal ecosystems、Coastal and Marine Management

Submarine groundwater discharge (SGD) is a nutrient source to coastal waters. However, most SGD estimates are restricted to a local scale and hardly distinguish contributions from fresh (FSGD) and recirculated (RSGD) SGD. Here, we compiled data on radium/radon of groundwater (n ~ 2000) and seawater (n ~ 10,000) samples along ~18,000 km of China’s coastal seas to resolve large scale FSGD and RSGD and their associated nutrient loads. Nearshore-scale FSGD ( ~ 3.56 × 108 m3 d−1) was only 2% of the total SGD but comparable to RSGD in terms of nutrient loads. Despite large uncertainties quantified via Monte Carlo simulations, SGD was a dominant contributor to China’s coastal nutrient budgets, with dissolved inorganic nitrogen, phosphorus and silicate fluxes of ~395, 2.9, and 581 Gmol a−1, respectively. Total SGD accounted for 19–54% of nutrient inputs, exceeding inputs from atmospheric deposition and rivers. Overall, SGD helps sustaining primary production along one of the most human-impacted marginal seas on Earth. The authors resolved large scale fresh and recirculated submarine groundwater discharge (SGD) and their associated nutrient fluxes in China’s coastal seas, revealing a dominant role of SGD in nutrient budgets.