Macroalgae contribute to nested mosaics of pH variability in a sub-Arctic fjord

Handle URI:
http://hdl.handle.net/10754/550844
Title:
Macroalgae contribute to nested mosaics of pH variability in a sub-Arctic fjord
Authors:
Krause-Jensen, D.; Duarte, Carlos M. ( 0000-0002-1213-1361 ) ; Hendriks, I. E.; Meire, L.; Blicher, M. E.; Marbà, N.; Sejr, M. K.
Abstract:
The Arctic Ocean is considered the most vulnerable ecosystem to ocean acidification (OA) and large-scale assessments of pH and the saturation state for aragonite (Ωarag) indicate that it is already close to corrosive states (Ωarag < 1). In high-latitude coastal waters the regulation of pH and Ωarag is far more complex than offshore because increased biological activity and input of glacial meltwater affect pH. As most calcifiers occupy coastal habitats, the assessment of risks from OA to these vulnerable organisms cannot be derived from extrapolation of current and forecasted offshore conditions, but requires an understanding of the regimes of pH and Ωarag in their coastal habitats. To increase knowledge of the natural variability of pH in the Arctic coastal zone and specifically to test the influence of benthic vegetated habitats, we quantified pH-variability in a Greenland fjord in a nested scale approach. A sensor array logging pH, O2, PAR, temperature and salinity was applied on spatial scales ranging from km-scale across the horizontal extension of the fjord, over 100 m scale vertically in the fjord, 10–100 m scale between subtidal habitats with and without kelp forests and between vegetated tidal pools and adjacent vegetated shores, to cm-m scale within kelp forests and mm-scale across boundary layers of macrophyte tissue. In addition, we assessed the temporal variability in pH on diurnal and seasonal scales. Based on pH-measurements combined with relationships between salinity, total alkalinity and dissolved inorganic carbon we also estimated variability of Ωarag. Results show variability in pH and Ωarag of up to 0.2–0.3 units at several scales, i.e. along the horizontal and vertical extension of the fjord, between seasons and on a diel basis in benthic habitats and within 1 m3 of kelp forest. Vegetated intertidal pools exhibited extreme diel pH variability of > 1.5 units and macrophyte boundary layers a pH-range of up to 0.8 units. Overall, Ωarag was favorable to calcification, and pelagic and benthic metabolism was an important driver of pH and Ωarag producing mosaics of variability from low levels in the dark to peak levels at high irradiance. We suggest that productive coastal environments may form niches of high pH in a future acidified Arctic Ocean.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Macroalgae contribute to nested mosaics of pH variability in a sub-Arctic fjord 2015, 12 (6):4907 Biogeosciences Discussions
Publisher:
European Geosciences Union
Journal:
Biogeosciences Discussions
Issue Date:
27-Mar-2015
DOI:
10.5194/bgd-12-4907-2015
Type:
Article
ISSN:
1810-6285
Additional Links:
http://www.biogeosciences-discuss.net/12/4907/2015/
Appears in Collections:
Articles; Red Sea Research Center (RSRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorKrause-Jensen, D.en
dc.contributor.authorDuarte, Carlos M.en
dc.contributor.authorHendriks, I. E.en
dc.contributor.authorMeire, L.en
dc.contributor.authorBlicher, M. E.en
dc.contributor.authorMarbà, N.en
dc.contributor.authorSejr, M. K.en
dc.date.accessioned2015-04-28T12:35:54Zen
dc.date.available2015-04-28T12:35:54Zen
dc.date.issued2015-03-27en
dc.identifier.citationMacroalgae contribute to nested mosaics of pH variability in a sub-Arctic fjord 2015, 12 (6):4907 Biogeosciences Discussionsen
dc.identifier.issn1810-6285en
dc.identifier.doi10.5194/bgd-12-4907-2015en
dc.identifier.urihttp://hdl.handle.net/10754/550844en
dc.description.abstractThe Arctic Ocean is considered the most vulnerable ecosystem to ocean acidification (OA) and large-scale assessments of pH and the saturation state for aragonite (Ωarag) indicate that it is already close to corrosive states (Ωarag < 1). In high-latitude coastal waters the regulation of pH and Ωarag is far more complex than offshore because increased biological activity and input of glacial meltwater affect pH. As most calcifiers occupy coastal habitats, the assessment of risks from OA to these vulnerable organisms cannot be derived from extrapolation of current and forecasted offshore conditions, but requires an understanding of the regimes of pH and Ωarag in their coastal habitats. To increase knowledge of the natural variability of pH in the Arctic coastal zone and specifically to test the influence of benthic vegetated habitats, we quantified pH-variability in a Greenland fjord in a nested scale approach. A sensor array logging pH, O2, PAR, temperature and salinity was applied on spatial scales ranging from km-scale across the horizontal extension of the fjord, over 100 m scale vertically in the fjord, 10–100 m scale between subtidal habitats with and without kelp forests and between vegetated tidal pools and adjacent vegetated shores, to cm-m scale within kelp forests and mm-scale across boundary layers of macrophyte tissue. In addition, we assessed the temporal variability in pH on diurnal and seasonal scales. Based on pH-measurements combined with relationships between salinity, total alkalinity and dissolved inorganic carbon we also estimated variability of Ωarag. Results show variability in pH and Ωarag of up to 0.2–0.3 units at several scales, i.e. along the horizontal and vertical extension of the fjord, between seasons and on a diel basis in benthic habitats and within 1 m3 of kelp forest. Vegetated intertidal pools exhibited extreme diel pH variability of > 1.5 units and macrophyte boundary layers a pH-range of up to 0.8 units. Overall, Ωarag was favorable to calcification, and pelagic and benthic metabolism was an important driver of pH and Ωarag producing mosaics of variability from low levels in the dark to peak levels at high irradiance. We suggest that productive coastal environments may form niches of high pH in a future acidified Arctic Ocean.en
dc.publisherEuropean Geosciences Unionen
dc.relation.urlhttp://www.biogeosciences-discuss.net/12/4907/2015/en
dc.rightsArchived with thanks to Biogeosciences Discussions.This work is distributed under the Creative Commons Attribution 3.0 License.en
dc.titleMacroalgae contribute to nested mosaics of pH variability in a sub-Arctic fjorden
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalBiogeosciences Discussionsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionArctic Research Centre, Bioscience, Arhus University, C. F. Møllers Allé 8, 8000 Århus C, Denmarken
dc.contributor.institutionDepartment of Bioscience, Arhus University, Vejlsøvej 25, 8600 Silkeborg, Denmarken
dc.contributor.institutionFaculty of Biosciences, Fisheries and Economics, University of Tromsø, Tromsø, Norwayen
dc.contributor.institutionDepartment of Global Change Research, IMEDEA (CSIC-UIB) Instituto Mediterráneo de Estudios Avanzados, Miquel Marqués 21, 07190 Esporles, Spainen
dc.contributor.institutionGreenland Climate Research Centre, Greenland Institute of Natural Resources, Kivioq 2, Box 570, 3900 Nuuk, Greenlanden
dc.contributor.institutionMarine Biology Laboratory, University of Ghent (UGent), Krijgslaan 281 (S8), 9000 Gent, Belgiumen
kaust.authorDuarte, Carlos M.en
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