Effects of elevated pCO2 on the metabolism of a temperate rhodolith Lithothamnion corallioides grown under different temperatures. Issue 4 (28th June 2013)

• Record Type: Journal Article
• Authors: Noisette, Fanny; Duong, Gwendoline; Six, Christophe; Davoult, Dominique; Martin, Sophie; Hurd, C.
• Is Part Of: Journal of phycology. Volume 49:Issue 4(2013:Aug.)
• Page Start: 746
• Page End: 757
• Publication Date: 2013-06-28
• Subjects: Algae -- Periodicals; 579.8
• DOI: 10.1111/jpy.12085
• Languages: English
• ISSNs: 0022-3646

Abstract

<abstract abstract-type="main" id="jpy12085-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Coralline algae are considered among the most sensitive species to near future ocean acidification. We tested the effects of elevated <italic>p</italic>CO<sub>2</sub> on the metabolism of the free‐living coralline alga <italic>Lithothamnion corallioides</italic> ("maerl") and the interactions with changes in temperature. Specimens were collected in North Brittany (France) and grown for 3 months at <italic>p</italic>CO<sub>2</sub> of 380 (ambient <italic>p</italic>CO<sub>2</sub>), 550, 750, and 1000 μatm (elevated <italic>p</italic>CO<sub>2</sub>) and at successive temperatures of 10°C (ambient temperature in winter), 16°C (ambient temperature in summer), and 19°C (ambient temperature in summer +3°C). At each temperature, gross primary production, respiration (oxygen flux), and calcification (alkalinity flux) rates were assessed in the light and dark. Pigments were determined by HPLC. Chl <italic>a</italic>, carotene, and zeaxanthin were the three major pigments found in <italic>L. corallioides</italic> thalli. Elevated <italic>p</italic>CO<sub>2</sub> did not affect pigment content while temperature slightly decreased zeaxanthin and carotene content at 10°C. Gross production was not affected by temperature but was significantly affected by <italic>p</italic>CO<sub>2</sub> with an increase between 380 and 550 μatm. Light, dark, and diel (24 h) calcification rates strongly decreased with increasing <italic>p</italic>CO<sub>2</sub> regardless of the temperature. Although elevated <italic>p</italic>CO<sub>2</sub> only slightly affected gross production in <italic>L. corallioides</italic>, diel net calcification was reduced by up to 80% under the 1, 000 μatm treatment. Our findings suggested that near future levels of CO<sub>2</sub> will have profound consequences for carbon and carbonate budgets in rhodolith beds and for the sustainability of these habitats.</p> </abstract>