Cold-water corals and hydrochemistry - is there a unifying link?

• Main Authors: Flögel, S., Rüggeberg, A., Mienis, F., Dullo, W.-C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2010
• Subjects: Northeast Atlantic
• Online Access: https://www.vliz.be/imisdocs/publications/228665.pdf

Physical and chemical parameters were measured in five different regions of the Northeast Atlantic with knownoccurrences of cold-water coral reefs and mounds and in the Mediterranean, where these corals form livingcarpets over existing morphologies. In this study we analyzed 282 bottom water samples regarding delta13CDIC,delta18O, and DIC. The hydrochemical data reveal characteristic patterns and differences for cold-water coralsites with living coral communities and ongoing reef and mound growth at the Irish and Norwegian sites. Whilethe localities in the Mediterranean, in the Gulf of Cadiz, and off Mauritania show only patchy coral growth onmound-like reliefs and various substrates.The analysis of delta13C/delta18O reveals distinct clusters for the different regions and the respective bottomwater masses bathing the delta18O, and especially between delta13CDIC and DIC shows that DIC is a parameterwith high sensitivity to the mixing of bottom water masses. It varies distinctively between sites with livingreefs/mounds and sites with restricted patchy growth or dead corals. Results suggest that DIC and delta13CDICcan provide additional insights into the mixing of bottom water masses.Prolific cold-water coral growth forming giant biogenic structures plot into a narrow geochemical windowcharacterized by a variation of delta13CDIC between 0.45 and 0.79 per mille being associated with the water masshaving a density of sigma-theta of 27.50.15 kg m-3.