Work

Resolving distribution and controls of terrigenous and marine particulate organic matter across an energetic shelf

Year: 2026

Type: article

Abstract: . We assess the sources, distribution and controls of particulate organic matter (POM) across the northeastern Taiwan Strait, where monsoonal forcing, water-mass mixing, riverine inputs and sediment resuspension modulate particle dynamics. By integrating lignin biomarkers, bulk geochemistry, and sedimentary constraints within a two-step quantification approach, we demonstrate the influence of river discharge, plume intrusions, and seafloor resuspension on the distribution of terrigenous POM. Terrigenous particulate organic carbon (POCterr) represents a minor component in most water samples but becomes substantial in resuspension-dominated layers. Combining estimated POCterr with modeled current velocities yields an export flux of ~243 ± 56 kt C yr‒1, consistent with the regional imbalance between riverine input and sedimentary burial. After correction for terrigenous influence, bulk POM properties exhibit features reflecting nutrient supply, photoacclimation, and temperature-dependent variation in stable carbon isotopic (δ13C) composition. Comparisons with co-sampled surface sediments show that biomarker signals are preserved more faithfully than δ13C of organic matter, which is strongly modulated by lateral transport. This study provides a practical framework for quantifying terrigenous and marine POM in continental-shelf settings and offers improved constraints for interpreting source-to-sink processes and sedimentary archives.

Source: Biogeosciences

DOI: 10.5194/bg-23-4243-2026