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Responses of seaweeds that use CO2 as their sole inorganic carbon source to ocean acidification: differential effects of fluctuating pH but little benefit of CO2 enrichment

Citation

Britton, D and Mundy, CN and McGraw, CM and Revill, AT and Hurd, CL, Responses of seaweeds that use CO2 as their sole inorganic carbon source to ocean acidification: differential effects of fluctuating pH but little benefit of CO2 enrichment, ICES Journal of Marine Science pp. 1-12. ISSN 1054-3139 (2019) [Refereed Article]

Copyright Statement

Copyright 2019 International Council for the Exploration of the Sea

DOI: doi:10.1093/icesjms/fsz070

Abstract

Laboratory studies that test the responses of coastal organisms to ocean acidification (OA) typically use constant pH regimes which do not reflect coastal systems, such as seaweed beds, where pH fluctuates on diel cycles. Seaweeds that use CO2 as their sole inorganic carbon source (non-carbon dioxide concentrating mechanism species) are predicted to benefit from OA as concentrations of dissolved CO2 increase, yet this prediction has rarely been tested, and no studies have tested the effect of pH fluctuations on non-CCM seaweeds. We conducted a laboratory experiment in which two ecologically dominant non-CCM red seaweeds (Callophyllis lambertii and Plocamium dilatatum) were exposed to four pH treatments: two static, pHT 8.0 and 7.7 and two fluctuating, pHT 8.0  0.3 and 7.7  0.3. Fluctuating pH reduced growth and net photosynthesis in C. lambertii, while P. dilatatum was unaffected. OA did not benefit P. dilatatum, while C. lambertii displayed elevated net photosynthetic rates. We provide evidence that carbon uptake strategy alone cannot be used as a predictor of seaweed responses to OA and highlight the importance of species-specific sensitivity to [H+]. We also emphasize the importance of including realistic pH fluctuations in experimental studies on coastal organisms.

Item Details

Item Type:Refereed Article
Keywords:carbon dioxide concentrating mechanisms (CCM), dissolved inorganic carbon, macroalgae, non-CCM, ocean acidification (OA), pH variability, physiology, seaweed
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Phycology (incl. Marine Grasses)
Objective Division:Environment
Objective Group:Climate and Climate Change
Objective Field:Ecosystem Adaptation to Climate Change
UTAS Author:Britton, D (Mr Damon Britton)
UTAS Author:Mundy, CN (Dr Craig Mundy)
UTAS Author:Hurd, CL (Professor Catriona Hurd)
ID Code:135379
Year Published:2019
Web of Science® Times Cited:3
Deposited By:Ecology and Biodiversity
Deposited On:2019-10-16
Last Modified:2019-11-11
Downloads:0

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