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

Authors

  • Javier Arístegui,

    1. Departamento de Biología, Universidad de las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
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  • Carlos M. Duarte,

    1. Instituto Mediterráneo de Estudios Avanzados (IMEDEA), Consejo Superior de Investigaciones Científicas–Universidad de las Islas Baleares (CSIC-UiB), Esporles, Spain
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  • Josep M. Gasol,

    1. Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar–Centre Mediteranei d'Investigacions Marines i Ambientals (ICM-CMIMA), Consejo Superior de Investigaciones Científicas, Barcelona, Spain
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  • Laura Alonso-Sáez

    1. Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar–Centre Mediteranei d'Investigacions Marines i Ambientals (ICM-CMIMA), Consejo Superior de Investigaciones Científicas, Barcelona, Spain
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Abstract

[1] 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 l−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.

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