Coastal black-carbon budgets need a groundwater pathway

Wet-season measurements in China's Beibu Gulf show rivers dominate dissolved black-carbon transport, while non-riverine routes add a measurable fraction.

Wild Lands Ecological Intelligence Editor
Wild Lands Institute · 1 November 2026

Evidence: Peer-reviewed
Geography: Northern Beibu Gulf, China
System: River-ocean carbon pathways and submarine groundwater

WHAT THE EVIDENCE SAYS

Seasonal coastal observations and salinity mixing analysis estimated approximately 8.0 tonnes/day dissolved black-carbon input from rivers and 1.7 tonnes/day from non-riverine sources in the wet season, attributed primarily to submarine groundwater discharge.

WHY IT MATTERS / OUR READ

Coastal budgets that stop at mapped river mouths may miss material pathways beneath shorelines.

CAVEATS / UNCERTAINTY

Concentrations and fluxes rely on reconstructed endmembers; non-riverine inputs are not experimentally isolated to groundwater alone.

SOURCE

JGR Oceans — Zhang et al. (29 Oct 2026)
View original evidence ↗