eCite Digital Repository

Variability in the benefits of ocean acidification to photosynthetic rates of macroalgae without CO2-concentrating mechanisms


Cornwall, CE and Hurd, CL, Variability in the benefits of ocean acidification to photosynthetic rates of macroalgae without CO2-concentrating mechanisms, Marine and Freshwater Research, 71, (3) pp. 275-280. ISSN 1323-1650 (2020) [Refereed Article]

Copyright Statement

Copyright 2020 CSIRO

DOI: doi:10.1071/MF19134


Increasing concentrations of surface-seawater carbon dioxide (CO2) (ocean acidification) could favour seaweed species that currently are limited for dissolved inorganic carbon (DIC). Among them, those that are unable to use CO2-concentrating mechanisms (CCMs) to actively uptake bicarbonate (HCO3) across the plasmalemma are most likely to benefit. Here, we assess how the DIC uptake and photosynthetic rates of three rhodophytes without CCMs respond to four seawater CO2 concentrations representing pre-industrial (280μatm), present-day (400μatm), representative concentration pathway (RCP) emissions scenario 8.52050 (650μatm) and RCP 8.52100 (1000μatm). We demonstrated that the photosynthetic rates of only one species increase between the preindustrial and end-of-century scenarios, but because of differing photosynthetic quotients (DIC taken up relative to O2 evolved), all three increase their DIC uptake rates from pre-industrial or present-day scenarios to the end-of-century scenario. These variable, but generally beneficial, responses highlight that not all species without CCMs will respond to ocean acidification uniformly. This supports past assessments that, on average, this group will likely benefit from the impacts of ocean acidification. However, more concerted efforts are now required to assess whether similar benefits to photosynthetic rates and DIC uptake are also observed in chlorophytes and ochrophytes without CCMs.

Item Details

Item Type:Refereed Article
Keywords:seaweed, ocean acidification, inorganic carbon, physiology, bicarbonate, carbon-concentrating mechanisms, carbon dioxide, carbon use, DIC use, non-CCM species, pCO2
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:Adaptation to climate change
Objective Field:Ecosystem adaptation to climate change
UTAS Author:Cornwall, CE (Dr Chris Cornwall)
UTAS Author:Hurd, CL (Professor Catriona Hurd)
ID Code:139412
Year Published:2020
Web of Science® Times Cited:14
Deposited By:Ecology and Biodiversity
Deposited On:2020-06-15
Last Modified:2020-12-22

Repository Staff Only: item control page