pH up-regulation as a potential mechanism for the cold-water coral Lophelia pertusa to sustain growth in aragonite undersaturated conditions.

Wall, Marlene, Ragazzola, Federica, Foster, L. C., Form, Armin U. and Schmidt, D. N. (2015) pH up-regulation as a potential mechanism for the cold-water coral Lophelia pertusa to sustain growth in aragonite undersaturated conditions. Open Access Biogeosciences (BG), 12 (23). pp. 6869-6880. DOI 10.5194/bg-12-6869-2015.

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Cold-water corals are important habitat formers in deep-water ecosystems and at high latitudes. Ocean acidification and the resulting change in aragonite saturation are expected to affect these habitats and impact coral growth. Counter to expectations, the impact of saturation changes on the deep water coral Lophelia pertusa has been found to be less than expected, with the species sustaining growth even in undersaturated conditions. However, it is important to know whether such acclimation modifies the skeleton and thus its ecosystem functioning. Here we used Synchrotron X-Ray Tomography and Raman spectroscopy to examine changes in skeleton morphology and fibre orientation. We combined the morphological assessment with boron isotope analysis to determine if changes in growth are related to changes in control of calcification pH. Skeletal morphology is highly variable without clear changes in different saturation states. Raman investigations found no difference in macromorphological skeletal arrangement of early mineralization zones and secondary thickening between the treatments but revealed that the skeletal organic matrix layers were less distinct. The δ11B analyses show that L. pertusa up-regulates the internal calcifying fluid pH (pHcf) during calcification with disregard to ambient seawater pH and suggests that well-fed individuals can sustain a high internal pHcf. This indicates that any extra energetic demand required for calcification at low saturation is not detrimental to the skeletal morphology.

Document Type: Article
Funder compliance: info:eu-repo/grantAgreement/EC/FP7/215157
Keywords: ALKOR; AL316; JAGO
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-MG Marine Geosystems
OceanRep > The Future Ocean - Cluster of Excellence
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BI Biological Oceanography
Corresponding Author:
Corresponding Author Name
Wall, Marlene
Wall, Marlene
FB3-EOE-B Experimental Ecology - Benthic Ecology
Refereed: Yes
Open Access Journal?: Yes
Publisher: Copernicus Publications (EGU)
Projects: BIOACID, EPOCA, CalMarO, Future Ocean
Date Deposited: 01 Jun 2015 08:03
Last Modified: 19 Dec 2017 12:48

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