Active mesopelagic prokaryotes support high respiration in the subtropical northeast Atlantic Ocean

• Published in: Geophysical Research Letters
• Main Authors: Arístegui, Javier, Duarte, Carlos M., Gasol, Josep M., Alonso-Sáez, Laura
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2005
• Subjects: Northeast Atlantic
• Online Access: http://hdl.handle.net/10261/88472; https://doi.org/10.1029/2004GL021863

Here we provide evidence, based on prokaryote metabolic proxies and direct estimates of oxygen consumption, that the mesopelagic prokaryote assemblage in the subtropical Northeast Atlantic is an active one. It supports a high respiration (0.22 ± 0.05 μmol O2 1-1 d-1, corresponding to 68 ± 8 mmol CO2 m-2 d-1), comparable to that of the epipelagic zone during the same period (64-97 mmol C m-2 d-1). Our findings suggest that mesopelagic prokaryotes in the NE subtropical Ocean, as well as in other eastern boundary regions, are important carbon sinks for organic matter advected from the highly productive coastal systems, and would play a key role in the global carbon cycle of the oceans. Copyright 2005 by the American Geophysical Union. Peer Reviewed