Deep-Ocean dissolved organic matter reactivity along the Mediterranea Sea: does size matter?
| Autor: | Javier Arístegui, Xosé Antón Álvarez-Salgado, Mar Nieto-Cid, Alba María Martínez-Pérez |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences Microbial carbon pump conceptual framework Science Apparent oxygen utilisation Size-reactivity continuum (SRC) model Biology 01 natural sciences Deep sea size Article Carbon cycle Global carbon cycle Mediterranean sea Dissolved organic carbon carbon cycle Mediterranean Sea DOM 0105 earth and related environmental sciences organic matter Multidisciplinary Deep-sea DOM reactivity Ecology 010604 marine biology & hydrobiology carbon dissolved organic matter Salinity Environmental chemistry Medicine |
| Zdroj: | e-IEO. Repositorio Institucional Digital de Acceso Abierto del Instituto Español de Oceanografía instname Scientific Reports Digital.CSIC. Repositorio Institucional del CSIC Scientific Reports, Vol 7, Iss 1, Pp 1-8 (2017) |
| Popis: | Original research paper Despite of the major role ascribed to marine dissolved organic matter (DOM) in the global carbon cycle, the reactivity of this pool in the dark ocean is still poorly understood. Present hypotheses, posed within the size-reactivity continuum (SRC) and the microbial carbon pump (MCP) conceptual frameworks, need further empirical support. Here, we provide field evidence of the soundness of the SRC model. We sampled the high salinity core-of-flow of the Levantine Intermediate Water along its westward route through the entire Mediterranean Sea. At selected sites, DOM was size-fractionated in apparent high (aHMW) and low (aLMW) molecular weight fractions using an efficient ultrafiltration cell. A percentage decline of the aHMW DOM from 68–76% to 40–55% was observed from the Levantine Sea to the Strait of Gibraltar in parallel with increasing apparent oxygen utilization (AOU). DOM mineralization accounted for 30±3% of the AOU, being the aHMW fraction solely responsible for this consumption, verifying the SRC model in the field. We also demonstrate that, in parallel to this aHMW DOM consumption, fluorescent humic-like substances accumulate in both fractions and protein-like substances decline in the aLMW fraction, thus indicating that not only size matters and providing field support to the MCP model HOTMIX (grant number CTM2011–30010-C02 01-MAR and 02-MAR) and the project FERMIO (MINECO, CTM2014-57334-JIN), both co-financed with FEDER funds; (reference BES-2012- 056175) from the Spanish Ministry of Economy, Industry and Competitivenes; the project MODMED from CSIC (PIE, 201730E020) and CSIC Program “Junta para la Ampliación de Estudios” co-financed by the ESF (reference JAE DOC 040) 2,927 |
| Databáze: | OpenAIRE |
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