Remineralization of Contrasting Organic Matter Sources by Coastal Arctic Benthos

Arctic fjords and river delta systems often exhibit high organic matter burial rates making themimportant sites for potential blue carbon storage and sequestration. However, benthicorganisms can greatly reduce this potential through feeding and respiration, processes whichreturn a fraction of organic carbon back into the environment as dissolved inorganic carbon(DIC). To compare remineralization rates of organic matter in coastal Arctic habitats, sedimentcore incubations were conducted in a river delta system on Svalbard and in fjords in WestGreenland. During incubations, contrasting organic matter sources (phytoplankton and kelp)were added to the cores and the resulting fluxes of dissolved oxygen, nutrients, and DIC weremeasured. The results of these experiments provide insights into the variability of organicmatter remineralization rates in the Arctic and highlight the role that benthic communitiesplay in carbon storage and sequestration processes.