Disclaimer: This document is part of a deliverable not yet approved by the European Commission. The file “Zenodo_EURO-CARBON_Dataset_FullDataset_v1.xlsx” represents the first comprehensive dataset on blue carbon in marine sediments across European seas. This dataset is described in detail in the publication: Graversen et al. (2025), A marine and salt marsh sediment organic carbon database for European regional seas (EURO-CARBON), Data in Brief, Volume 60, June 2025, Article 111595. https://doi.org/10.1016/j.dib.2025.111595. Please note that the original dataset (v1) contained some errors, which have been corrected in the updated version: Zenodo_EURO-CARBON_Dataset_FullDataset_v2.xlsx. We apologize for any inconvenience this may have caused. The following changes have been made: Sediment sheet 46326-46596: The dry bulk density values have been removed. Entries marked as “Bare sediment” in “Habitat” column have been changed to “Seagrass (Zostera marina)”. A note has been added to indicate whether the Zostera marina beds were sparse or dense: 30554-30562 (Dense); 30563-30572 (Sparse) ; 30581-50588 (Dense); 30589- 30597 (Sparse); 30607-30615 (Dense); 30616-30617 (Sparse); 30627-30630 (Dense); 30631-30639 (Sparse); 30649-30656 (Dense); 30657-30664 (Sparse); 30671-30676 (Dense); 30683-30689 (Sparse); 30690-30696 (Dense); 30697-30703 (Sparse); 30710-30716 (Dense); 30725-30736 (Sparse); 30737-30740 (Dense); 30741-30742 (Sparse); 30743-30744 (Dense); 30751-30756 (Sparse); 30763-30768 (Dense); 30769-30774 (Sparse); 30775-30780 (Dense); 30788-30796 (Sparse); 30797-30803 (Dense); 30810-30815 (Sparse); 30823-30834 (Dense); 30835-30841 (Sparse); 30848-30849 (Sparse); 30850- 30853 (Dense); 30854-30855 (Sparse); 30862-30865 (Sparse); 30866-30869 (Dense); 30876-30882 (Sparse); 30883-30889 (Dense); 30897-30898 (Sparse); 30899-30901 (Dense); 30902-30904 (Sparse); 30910-30914 (Dense); 30915- 30916 (Sparse); 30917-30918 (Dense); 30919-30922 (Sparse); 30929-30934 (Sparse); 30935-30941 (Dense). Please note: The columns MAR (g/cm²/year) and MAR_se previously contained several unit inconsistencies. The following correction has been made: 12445–12469: MAR values were reported in g/cm²/ka instead of g/cm²/year; 29652-29765; MAR values were reported in g/m²/year instead of g/cm²/year; 37970-37993: MAR values are deleted; 38018-38036: MAR values are deleted; 38095-38118: MAR values are deleted; 43520-43526: All MAR values in this core have been adjusted to 0.017 g/cm²/year; 43534-43541: All MAR values in this core have been adjusted to 0.019 g/cm²/year; 43549-43558: All MAR values in this core have been adjusted to 0.074 g/cm²/year; 43563-43572: All MAR values in this core have been adjusted to 0.069 g/cm²/year; 48987-50177: MAR values were reported in g/cm2/ka instead of g/cm²/year; 50306-50339: MAR values were reported in g/cm2/ka instead of g/cm²/year; 50434-50534: MAR values were reported in g/cm2/ka instead of g/cm²/year. 12299-12305: CAR values were reported in g/cm2/ka instead of g/m²/year. 50434-50534: the wrong DOI is replaced with the correct: https://doi.pangaea.de/10.1594/PANGAEA.55155. 33103-33113 and 33159-33167 and 33200-33204: The values reported in the columns 14C_age and 14C_age_SD were not related to 14C dating. They were mistakenly entered and represented age information derived from Pb-210 dating. Therefore, the data in these cells has been deleted. In 5,287 cases, N-density was calculated based on available nitrogen percentage (N%) and dry bulk density (DBD). Similarly, P-density was calculated in 90 cases using available phosphorus percentage (P%) and DBD. Where these calculations were performed, it is indicated in the comment field. Biomass sheet 1424-1602: All information within these cells has been deleted. Same data as already present in cells 1-178. 2106-2282: All information within these cells has been deleted. Same data as already present in cells 1929-2105.