Sedimentology and age determination of sediment cores from the Penmarch'h and Guilvinec Canyons (Bay of Biscay)

DOI

In 1948, Le Danois reported for the first time the occurrence of living cold-water coral reefs, the so-called "massifs coralliens", along the European Atlantic continental margin. In 2008, a cruise with R/V Belgica was set out to re-investigate these cold-water corals in the Penmarc'h and Guilvinec Canyons along the Gascogne margin of the Bay of Biscay. During this cruise, an area of 560 km2 was studied using multibeam swath bathymetry, CTD casts, ROV observations and USBL-guided boxcoring.Based on the multibeam data and the ROV video imagery, two different cold-water coral reef settings were distinguished. In water depths ranging from 260 to 350 m, mini mounds up to 5 m high, covered by dead cold-water coral rubble, were observed. In between these mounds, soft sediment with a patchy distribution of gravel was recognised. The second setting (350-950 m) features hard substrates with cracks, spurs, cliffs and overhangs. In water depths of 700 to 950 m, both living and dead cold-water corals occur. Occasionally, they form dense coral patches with a diameter of about 10-60 m, characterised by mostly stacked dead coral rubble and a few living specimens. U/Th datings indicate a shift in cold-water coral growth after the Late Glacial Maximum (about 11.5 ka BP) from shallow to deep-water settings.The living cold-water corals from the deeper area occur in a water density (sigma-theta) of 27.35-27.55 kg/m3, suggested to be a prerequisite for the growth and distribution of cold-water coral reefs along the northern Atlantic margin. In contrast, the dead cold-water coral fragments in the shallow area occur in a density range of 27.15-27.20 kg/m**3 which is slightly outside the density range where living cold-water corals normally occur. The presented data suggest that this prerequisite is also valid for coral growth in the deeper canyons (> 350 m) in the Bay of Biscay.

For the physical oceanography see doi:10.1594/PANGAEA.773290. The multibeam contour maps can be found in doi:10.1594/PANGAEA.759003

Supplement to: De Mol, Lies; Van Rooij, David; Pirlet, Hans; Greinert, Jens; Frank, Norbert; Quemmerais, Frédéric; Henriet, Jean-Pierre (2011): Cold-water coral habitats in the Penmarc'h and Guilvinec Canyons (Bay of Biscay): Deep-water versus shallow-water settings. Marine Geology, 282(1-2), 40-52

Identifier
DOI https://doi.org/10.1594/PANGAEA.773526
Related Identifier https://doi.org/10.1016/j.margeo.2010.04.011
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.773526
Provenance
Creator De Mol, Lies; Van Rooij, David ORCID logo; Pirlet, Hans ORCID logo; Greinert, Jens ORCID logo; Frank, Norbert ORCID logo; Quemmerais, Frédéric; Henriet, Jean-Pierre
Publisher PANGAEA
Publication Year 2011
Funding Reference Seventh Framework Programme https://doi.org/10.13039/100011102 Crossref Funder ID 226354 https://cordis.europa.eu/project/id/226354 Hotspot Ecosystem Research and Mans Impact On European Seas
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 6 datasets
Discipline Earth System Research
Spatial Coverage (-5.496W, 46.908S, -5.256E, 46.975N); Gulf of Biscay
Temporal Coverage Begin 2008-05-31T13:04:00Z
Temporal Coverage End 2008-06-04T13:36:00Z