Mean sediment grain size, total organic carbon content, and carbon isotopic compositions of TOC and solid-phase extracted DOC in bottom water and porewater samples from the German Bight of the North Sea, during RV Heincke cruises HE582 and HE595

This data summarizes site information, sediment textural properties, and bulk geochemical parameters from the same sampling campaigns, including mean grain size, total organic carbon (TOC) content, and carbon isotopic compositions (δ¹³C and F¹⁴C) of both TOC and SPE-DOC in bottom water (BW) and porewater (PW) samples. These data establish the baseline for evaluating the sources, reactivity, and age of organic carbon in sediments and porewaters of the German Bight. Together with the molecular results in doi:10.1594/PANGAEA.989754, they constrain the coupling between sedimentary organic carbon pools and dissolved organic matter dynamics in this shallow-marine environment.