Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian
© 2017 John Wiley & Sons Ltd Anthropogenic nutrient inputs enhance microbial respiration within many coastal ecosystems, driving concurrent hypoxia and acidification. During photosynthesis, Symbiodinium spp., the microalgal endosymbionts of cnidarians and other marine phyla, produce O2 and assim...
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ftunivtsydney:oai:opus.lib.uts.edu.au:10453/125226 2023-05-15T17:52:01+02:00 Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian Klein, SG Pitt, KA Nitschke, MR Goyen, S Welsh, DT Suggett, DJ Carroll, AR 2017-09-01 application/pdf http://hdl.handle.net/10453/125226 unknown http://purl.org/au-research/grants/arc/DP160100271 Global Change Biology 10.1111/gcb.13718 Global Change Biology, 2017, 23 (9), pp. 3690 - 3703 1354-1013 http://hdl.handle.net/10453/125226 Ecology Animals Cnidaria Dinoflagellida Symbiosis Photosynthesis Hydrogen-Ion Concentration Hypoxia Journal Article 2017 ftunivtsydney 2022-03-13T13:33:26Z © 2017 John Wiley & Sons Ltd Anthropogenic nutrient inputs enhance microbial respiration within many coastal ecosystems, driving concurrent hypoxia and acidification. During photosynthesis, Symbiodinium spp., the microalgal endosymbionts of cnidarians and other marine phyla, produce O2 and assimilate CO2 and thus potentially mitigate the exposure of the host to these stresses. However, such a role for Symbiodinium remains untested for noncalcifying cnidarians. We therefore contrasted the fitness of symbiotic and aposymbiotic polyps of a model host jellyfish (Cassiopea sp.) under reduced O2 (~2.09 mg/L) and pH (~ 7.63) scenarios in a full-factorial experiment. Host fitness was characterized as asexual reproduction and their ability to regulate internal pH and Symbiodinium performance characterized by maximum photochemical efficiency, chla content and cell density. Acidification alone resulted in 58% more asexual reproduction of symbiotic polyps than aposymbiotic polyps (and enhanced Symbiodinium cell density) suggesting Cassiopea sp. fitness was enhanced by CO2-stimulated Symbiodinium photosynthetic activity. Indeed, greater CO2 drawdown (elevated pH) was observed within host tissues of symbiotic polyps under acidification regardless of O2 conditions. Hypoxia alone produced 22% fewer polyps than ambient conditions regardless of acidification and symbiont status, suggesting Symbiodinium photosynthetic activity did not mitigate its effects. Combined hypoxia and acidification, however, produced similar numbers of symbiotic polyps compared with aposymbiotic kept under ambient conditions, demonstrating that the presence of Symbiodinium was key for mitigating the combined effects of hypoxia and acidification on asexual reproduction. We hypothesize that this mitigation occurred because of reduced photorespiration under elevated CO2 conditions where increased net O2 production ameliorates oxygen debt. We show that Symbiodinium play an important role in facilitating enhanced fitness of Cassiopea sp. polyps, and perhaps also other noncalcifying cnidarian hosts, to the ubiquitous effects of ocean acidification. Importantly we highlight that symbiotic, noncalcifying cnidarians may be particularly advantaged in productive coastal waters that are subject to simultaneous hypoxia and acidification. Article in Journal/Newspaper Ocean acidification University of Technology Sydney: OPUS - Open Publications of UTS Scholars |
institution |
Open Polar |
collection |
University of Technology Sydney: OPUS - Open Publications of UTS Scholars |
op_collection_id |
ftunivtsydney |
language |
unknown |
topic |
Ecology Animals Cnidaria Dinoflagellida Symbiosis Photosynthesis Hydrogen-Ion Concentration Hypoxia |
spellingShingle |
Ecology Animals Cnidaria Dinoflagellida Symbiosis Photosynthesis Hydrogen-Ion Concentration Hypoxia Klein, SG Pitt, KA Nitschke, MR Goyen, S Welsh, DT Suggett, DJ Carroll, AR Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
topic_facet |
Ecology Animals Cnidaria Dinoflagellida Symbiosis Photosynthesis Hydrogen-Ion Concentration Hypoxia |
description |
© 2017 John Wiley & Sons Ltd Anthropogenic nutrient inputs enhance microbial respiration within many coastal ecosystems, driving concurrent hypoxia and acidification. During photosynthesis, Symbiodinium spp., the microalgal endosymbionts of cnidarians and other marine phyla, produce O2 and assimilate CO2 and thus potentially mitigate the exposure of the host to these stresses. However, such a role for Symbiodinium remains untested for noncalcifying cnidarians. We therefore contrasted the fitness of symbiotic and aposymbiotic polyps of a model host jellyfish (Cassiopea sp.) under reduced O2 (~2.09 mg/L) and pH (~ 7.63) scenarios in a full-factorial experiment. Host fitness was characterized as asexual reproduction and their ability to regulate internal pH and Symbiodinium performance characterized by maximum photochemical efficiency, chla content and cell density. Acidification alone resulted in 58% more asexual reproduction of symbiotic polyps than aposymbiotic polyps (and enhanced Symbiodinium cell density) suggesting Cassiopea sp. fitness was enhanced by CO2-stimulated Symbiodinium photosynthetic activity. Indeed, greater CO2 drawdown (elevated pH) was observed within host tissues of symbiotic polyps under acidification regardless of O2 conditions. Hypoxia alone produced 22% fewer polyps than ambient conditions regardless of acidification and symbiont status, suggesting Symbiodinium photosynthetic activity did not mitigate its effects. Combined hypoxia and acidification, however, produced similar numbers of symbiotic polyps compared with aposymbiotic kept under ambient conditions, demonstrating that the presence of Symbiodinium was key for mitigating the combined effects of hypoxia and acidification on asexual reproduction. We hypothesize that this mitigation occurred because of reduced photorespiration under elevated CO2 conditions where increased net O2 production ameliorates oxygen debt. We show that Symbiodinium play an important role in facilitating enhanced fitness of Cassiopea sp. polyps, and perhaps also other noncalcifying cnidarian hosts, to the ubiquitous effects of ocean acidification. Importantly we highlight that symbiotic, noncalcifying cnidarians may be particularly advantaged in productive coastal waters that are subject to simultaneous hypoxia and acidification. |
format |
Article in Journal/Newspaper |
author |
Klein, SG Pitt, KA Nitschke, MR Goyen, S Welsh, DT Suggett, DJ Carroll, AR |
author_facet |
Klein, SG Pitt, KA Nitschke, MR Goyen, S Welsh, DT Suggett, DJ Carroll, AR |
author_sort |
Klein, SG |
title |
Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
title_short |
Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
title_full |
Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
title_fullStr |
Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
title_full_unstemmed |
Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
title_sort |
symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian |
publishDate |
2017 |
url |
http://hdl.handle.net/10453/125226 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
http://purl.org/au-research/grants/arc/DP160100271 Global Change Biology 10.1111/gcb.13718 Global Change Biology, 2017, 23 (9), pp. 3690 - 3703 1354-1013 http://hdl.handle.net/10453/125226 |
_version_ |
1766159341447020544 |