Metabolic alkalinity release from large port facilities (Hamburg, Germany) and impact on coastal carbon storage

[摘要] Metabolic activities in estuaries, especially these of large rivers,profoundly affect the downstream coastal biogeochemistry. Here, we unravelthe impacts of large industrial port facilities, showing that elevatedmetabolic activity in the Hamburg port (Germany) increases total alkalinity(TA) and dissolved inorganic carbon (DIC) runoff to the North Sea. Theimports of particulate inorganic carbon, particulate organic carbon, andparticulate organic nitrogen (PIC, POC, and PON) from the upstream ElbeRiver can fuel up to 90 % of the TA generated in the entire estuary viacalcium carbonate (CaCO 3 ) dissolution. The remaining at least 10 %of TA generation can be attributed to anaerobic metabolic processes such asdenitrification of remineralized PON or other pathways. The Elbe Estuary asa whole adds approximately 15 % to the overall DIC and TA runoff. Boththe magnitude and partitioning among these processes appear to be sensitiveto climatic and anthropogenic changes. Thus, with increased TA loads, thecoastal ocean (in particular) would act as a stronger CO 2 sink,resulting in changes to the overall coastal system's capacity to storeCO 2 .

[学科分类] 大气科学