Bergstrom, E and Ordonez, A and Ho, M and Hurd, C and Fry, B and Diaz-Pulido, G, Inorganic carbon uptake strategies in coralline algae: plasticity across evolutionary lineages under ocean acidification and warming, Marine Environmental Research, 161 Article 105107. ISSN 0141-1136 (2020) [Refereed Article]
© 2020 Elsevier Ltd. All rights reserved.
Dissolved inorganic carbon (DIC) assimilation is essential to the reef-building capacity of crustose coralline algae (CCA). Little is known, however, about the DIC uptake strategies and their potential plasticity under ongoing ocean acidification (OA) and warming. The persistence of CCA lineages throughout historical oscillations of pCO2 and temperature suggests that evolutionary history may play a role in selecting for adaptive traits. We evaluated the effects of pCO2 and temperature on the plasticity of DIC uptake strategies and associated energetic consequences in reef-building CCA from different evolutionary lineages. We simulated past, present, moderate (IPCC RCP 6.0) and high pCO2 (RCP 8.5) and present and high (RCP 8.5) temperature conditions and quantified stable carbon isotope fractionation (13ε), organic carbon content, growth and photochemical efficiency. All investigated CCA species possess CO2-concentrating mechanisms (CCMs) and assimilate CO2 via diffusion to varying degrees. Under OA and warming, CCA either increased or maintained CCM capacity, which was associated with overall neutral effects on metabolic performance. More basal taxa, Sporolithales and Hapalidiales, had greater capacity for diffusive CO2 use than Corallinales. We suggest that CCMs are an adaptation that supports a robust carbon physiology and are likely responsible for the endurance of CCA in historically changing oceans.
|Item Type:||Refereed Article|
|Keywords:||climate change, ocean acidification, temperature, coralline algae, seaweed, ocean warming, isotopes, fractionation|
|Research Division:||Biological Sciences|
|Research Group:||Plant biology|
|Research Field:||Phycology (incl. marine grasses)|
|Objective Division:||Environmental Policy, Climate Change and Natural Hazards|
|Objective Group:||Understanding climate change|
|Objective Field:||Effects of climate change on Australia (excl. social impacts)|
|UTAS Author:||Hurd, C (Professor Catriona Hurd)|
|Funding Support:||Australian Research Council (DP160103071)|
|Web of Science® Times Cited:||5|
|Deposited By:||Ecology and Biodiversity|
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