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| Titel |
Bioavailability of sinking organic matter in the Blanes canyon and the adjacent open slope (NW Mediterranean Sea) |
| VerfasserIn |
P. Lopez-Fernandez, S. Bianchelli, A. Pusceddu, A. Calafat, A. Sanchez-Vidal, R. Danovaro |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 5 ; Nr. 10, no. 5 (2013-05-23), S.3405-3420 |
| Datensatznummer |
250018259
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| Publikation (Nr.) |
 copernicus.org/bg-10-3405-2013.pdf |
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| Zusammenfassung |
| Submarine canyons are sites of intense energy and material
exchange between the shelf and the deep adjacent basins. To test the
hypothesis that active submarine canyons represent preferential conduits of
available food for the deep-sea benthos, two mooring lines were deployed at
1200 m depth from November 2008 to November 2009 inside the Blanes canyon
and on the adjacent open slope (Catalan Margin, NW Mediterranean Sea). We
investigated the fluxes, biochemical composition and food quality of sinking
organic carbon (OC). OC fluxes in the canyon and the open slope varied among
sampling periods, though not consistently in the two sites. In particular,
while in the open slope the highest OC fluxes were observed in August 2009,
in the canyon the highest OC fluxes occurred in April–May 2009. For almost
the entire study period, the OC fluxes in the canyon were significantly
higher than those in the open slope, whereas OC contents of sinking
particles collected in the open slope were consistently higher than those in
the canyon. This result confirms that submarine canyons are effective
conveyors of OC to the deep sea. Particles transferred to the deep sea floor
through the canyons are predominantly of inorganic origin, significantly
higher than that reaching the open slope at a similar water depth. Using
multivariate statistical tests, two major clusters of sampling periods were
identified: one in the canyon that grouped trap samples collected in
December 2008, concurrently with the occurrence of a major storm at the sea
surface, and associated with increased fluxes of nutritionally available
particles from the upper shelf. Another cluster grouped samples from both
the canyon and the open slope collected in March 2009, concurrently with the
occurrence of the seasonal phytoplankton bloom at the sea surface, and
associated with increased fluxes of total phytopigments. Our results confirm
the key ecological role of submarine canyons for the functioning of deep-sea
ecosystems, and highlight the importance of canyons in linking episodic
storms and primary production occurring at the sea surface to the deep sea
floor. |
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