The short-term benthic response to an input of fresh organic matter was examined in vastly contrasting benthic environments (estuarine intertidal to deep-sea) using 13C-labeled diatoms as a tracer of labile carbon. Benthic processing was assessed in major compartments through 13C-enrichment in CO2, in bacteria-specific phospholipids and in fauna tissue. A rapid response was evident in all environments. Under warm bottom water (14–18°C), similar quantities of the added carbon were respired within 24 hours in shallow and deep-sea sediments. However, the speed and magnitude of respiration were strongly reduced under low bottom water temperature (4–6°C), both in a shallow and a deep-sea site. Rapid carbon respiration even in deep-sea sediments almost devoid of fauna highlights the key role of bacteria, the most ubiquitous benthic component, in this short-term respiration of fresh organic matter. However, when present, fauna rapidly ingest algal material, thereby increasing the amount of carbon processed and directly extending carbon flow pathways.
Original languageEnglish
JournalJournal of Marine Research
Journal publication date2005

ID: 387509