Raddatz, Jacek Liebetrau, Volker Trotter, Julie Rüggeberg, Andres Flögel, Sascha Dullo, Wolf-Christian Eisenhauer, Anton Voigt, Silke McCulloch, Malcolm 2016-10-01 High-latitude cold-water coral (CWC) reefs are particularly susceptible due to enhanced CO₂ uptake in these regions. Using precisely dated (U/Th) CWCs (Lophelia pertusa) retrieved during research cruise POS 391 (Lopphavet 70.6°N, Oslofjord 59°N) we applied boron isotopes (δ¹¹B), Ba/Ca, Li/Mg, and U/Ca ratios to reconstruct the environmental boundary conditions of CWC reef growth. The sedimentary record from these CWC reefs reveals a lack of corals between ~6.4 and 4.8 ka. The question remains if this phenomenon is related to changes in the carbonate system or other causes. The initial postglacial setting had elevated Ba/Ca ratios, indicative of meltwater fluxes showing a decreasing trend toward cessation at 6.4 ka with an oscillation pattern similar to continental glacier fluctuations. Downcore U/Ca ratios reveal an increasing trend, which is outside the range of modern U/Ca variability in L. pertusa, suggesting changes of seawater pH near 6.4 ka. The reconstructed bottom water temperature at Lopphavet reveals a striking similarity to Barent sea surface and subsea surface temperature records. We infer that meltwater pulses weakened the North Atlantic Current system, resulting in southward advances of cold and CO₂-rich Arctic waters. A corresponding shift in the δ¹¹B record from ~25.0‰ to ~27.0‰ probably implies enhanced pH up-regulation of the CWCs due to the higher pCO₂ concentrations of ambient seawater, which hastened mid-Holocene CWC reef decline on the Norwegian margin. application/pdf https://folia.unifr.ch/global/documents/305505 https://folia.unifr.ch/documents/305505/files/rug_ech.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1002/2016PA002974 info:eu-repo/semantics/openAccess License undefined Paleoceanography. - 2016, vol. 31, no. 10, p. 1350–1367 cold-water corals Lophelia pertusa boron isotopes Holocene pH upregulation Li/Mg info:eu-repo/classification/udc/574 Environmental constraints on Holocene cold‐water coral reef growth off Norway: Insights from a multiproxy approach http://purl.org/coar/resource_type/c_6501