Journal article
Ocean warming has greater and more consistent negative effects than ocean acidification on the growth and health of subtropical macroalgae
Marine Ecology - Progress Series, Vol.595, pp.55-69
14/05/2018
Metrics
8 Record Views
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Abstract
Macroalgae are the major habitat-forming organisms in many coastal temperate and subtropical marine systems. Although climate change has been identified as a major threat to the persistence of macroalgal beds, the combined effects of ocean warming and ocean acidification on algal performance are poorly understood. Here we investigate the effects of increased temperature and acidification on the growth, calcification and nutritional content of 6 common subtropical macroalgae; Sargassum linearifolium, Ulva sp., Amphiroa anceps, Corallina officinalis, Delisea pulchra and Laurencia decussata. Algae were reared in a factorial cross of 3 temperatures (23°C [ambient], 26°C and 28°C) and 3 pH levels (8.1 [ambient], 7.8 and 7.6) for 2 wk. The highest (28°C) temperature decreased the growth of all 6 macroalgal species, irrespective of the pH levels. In contrast, the effect of decreased pH on growth was variable. The growth of Ulva sp. and C. officinalis increased, L. decussata decreased, while the remaining 3 species were unaffected. Interestingly, the differential responses of macroalgae to ocean acidification were unrelated to whether or not a species was a calcifying alga, or their carbon-uptake mechanism—2 processes that are predicted to be sensitive to decreased pH. The growth of the calcifying algae (C. officinalis and A. anceps) was not affected by reduced pH but calcification of these 2 algae was reduced when exposed to a combination of reduced pH and elevated temperature. The 3 species capable of uptake of bicarbonate, S. linearifolium, L. decussata and Ulva sp., displayed positive, negative and neutral changes in growth, respectively, in response to reduced pH. The C:N ratio for 5 of the 6 species was unaffected by either pH or temperature. The consistent and predictable negative effects of temperature on the growth and calcification of subtropical macroalgae suggests that this stressor poses a greater threat to the persistence of subtropical macroalgal populations than ocean acidification under ongoing and future climate change.
Details
- Title
- Ocean warming has greater and more consistent negative effects than ocean acidification on the growth and health of subtropical macroalgae
- Creators
- Alexia Graba-Landry - Southern Cross UniversityAndrew S Hoey - James Cook UniversityJordan K Matley - University of the Virgin IslandsHannah Sheppard-Brennand - Southern Cross UniversityAlistair G B Poore - University of New South WalesMaria Byrne - University of SydneySymon A Dworjanyn - Southern Cross University
- Publication Details
- Marine Ecology - Progress Series, Vol.595, pp.55-69
- Publisher
- Inter-Research
- Grant note
- This study was supported in part by the New South Wales Environment Research Trust and the Centre for Coastal Biogeochemistry Honours Scholarship.
- Identifiers
- 991012927058302368
- Copyright
- Copyright © Inter-Research 2018
- Academic Unit
- Science; National Marine Science Centre; Faculty of Science and Engineering
- Language
- English
- Resource Type
- Journal article