Supporting data set for article 'Submarine groundwater discharge exceeds rivers as a source of dissolved carbon to the Bohai Sea'

Submarine groundwater discharge (SGD) is often overlooked when building carbon budgets in continental margins. Nevertheless, SGD may transport large amounts of carbon from terrestrial environments and coastal sediments to the ocean. Here, we resolve the relative contribution of coastal groundwater and river water as sources of carbon budgets in the Bohai Sea. We show that broadly-defined SGD-derived carbon contributes 50–90% to the dissolved carbon pool of the Bohai Sea. This magnitude is 4–10 times that of the dissolved carbon flux transported by rivers. The dissolved carbon flux transported by SGD can have implications for the acidification and eutrophication of coastal seawater. The impact of SGD on seawater acidification or buffering primarily determined by hydrogeological conditions. Our findings illustrate the significance of SGD as a crucial contributor to dissolved carbon in coastal oceans. Coastal carbon budgets should incorporate the influence of SGD.