Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae)
The worldwide effects of ocean acidification (OA) on marine species are a growing concern. In temperate coastal seas, seaweeds are dominant primary producers that create complex habitats and supply energy to higher trophic levels. Studies on OA and macroalgae have focused on calcifying species and a...
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ftunivnewengland:oai:rune.une.edu.au:1959.11/15833 2023-08-27T04:11:20+02:00 Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) Roleda, Michael Y Morris, Jaz N McGraw, Christina School of Science and Technology Hurd, Catriona L 2012 https://hdl.handle.net/1959.11/15833 en eng Wiley-Blackwell Publishing Ltd 10.1111/j.1365-2486.2011.02594.x https://hdl.handle.net/1959.11/15833 une:16070 Marine and Estuarine Ecology (incl Marine Ichthyology) Analytical Chemistry Journal Article 2012 ftunivnewengland 2023-08-10T19:38:12Z The worldwide effects of ocean acidification (OA) on marine species are a growing concern. In temperate coastal seas, seaweeds are dominant primary producers that create complex habitats and supply energy to higher trophic levels. Studies on OA and macroalgae have focused on calcifying species and adult stages, but critically, they have over-looked the microscopic stages of the reproductive life cycle, which, for other anthropogenic stressors, e.g., UV-B radiation, are the most susceptible life-history phase. Also, environmental cues and stressors can cause changes in the sex ratio, which has implications for the mating system and recruitment success. Here, we report the effects of pH (7.59 - 8.50) on meiospore germination and sex determination for the giant kelp, 'Macrocystis pyrifera' (Laminariales), in the presence and absence of additional dissolved inorganic carbon (DIC). Lowered pH (7.59 - 7.60, using HCl-only) caused a significant reduction in germination, whereas added DIC had the opposite effect, indicating that increased CO₂ at lower pH ameliorates physiological stress. This finding also highlights the importance of appropriate manipulation of seawater carbonate chemistry when testing the effects of OA on photosynthetic organisms. The proportion of male to female gametophytes did not vary significantly between treatments, suggesting that pH was not a primary environmental modulator of sex. Relative to the baseline (pH 8.19), gametophytes were 32% larger under moderate OA (pH 7.86) and 10% larger under extreme OA (pH 7.61). We suggest that metabolically active cells can compensate for the acidification of seawater. This homeostatic function minimizes the negative effects of lower pH (high H + ions) on cellular activity. The 6 - 9% reduction in germination success under extreme OA suggests that meiospores of 'M. pyrifera' may be resistant to future OA. Article in Journal/Newspaper Ocean acidification Research UNE - University of New England at Armidale, NSW Australia |
institution |
Open Polar |
collection |
Research UNE - University of New England at Armidale, NSW Australia |
op_collection_id |
ftunivnewengland |
language |
English |
topic |
Marine and Estuarine Ecology (incl Marine Ichthyology) Analytical Chemistry |
spellingShingle |
Marine and Estuarine Ecology (incl Marine Ichthyology) Analytical Chemistry Roleda, Michael Y Morris, Jaz N McGraw, Christina School of Science and Technology Hurd, Catriona L Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) |
topic_facet |
Marine and Estuarine Ecology (incl Marine Ichthyology) Analytical Chemistry |
description |
The worldwide effects of ocean acidification (OA) on marine species are a growing concern. In temperate coastal seas, seaweeds are dominant primary producers that create complex habitats and supply energy to higher trophic levels. Studies on OA and macroalgae have focused on calcifying species and adult stages, but critically, they have over-looked the microscopic stages of the reproductive life cycle, which, for other anthropogenic stressors, e.g., UV-B radiation, are the most susceptible life-history phase. Also, environmental cues and stressors can cause changes in the sex ratio, which has implications for the mating system and recruitment success. Here, we report the effects of pH (7.59 - 8.50) on meiospore germination and sex determination for the giant kelp, 'Macrocystis pyrifera' (Laminariales), in the presence and absence of additional dissolved inorganic carbon (DIC). Lowered pH (7.59 - 7.60, using HCl-only) caused a significant reduction in germination, whereas added DIC had the opposite effect, indicating that increased CO₂ at lower pH ameliorates physiological stress. This finding also highlights the importance of appropriate manipulation of seawater carbonate chemistry when testing the effects of OA on photosynthetic organisms. The proportion of male to female gametophytes did not vary significantly between treatments, suggesting that pH was not a primary environmental modulator of sex. Relative to the baseline (pH 8.19), gametophytes were 32% larger under moderate OA (pH 7.86) and 10% larger under extreme OA (pH 7.61). We suggest that metabolically active cells can compensate for the acidification of seawater. This homeostatic function minimizes the negative effects of lower pH (high H + ions) on cellular activity. The 6 - 9% reduction in germination success under extreme OA suggests that meiospores of 'M. pyrifera' may be resistant to future OA. |
format |
Article in Journal/Newspaper |
author |
Roleda, Michael Y Morris, Jaz N McGraw, Christina School of Science and Technology Hurd, Catriona L |
author_facet |
Roleda, Michael Y Morris, Jaz N McGraw, Christina School of Science and Technology Hurd, Catriona L |
author_sort |
Roleda, Michael Y |
title |
Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) |
title_short |
Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) |
title_full |
Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) |
title_fullStr |
Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) |
title_full_unstemmed |
Ocean acidification and seaweed reproduction: increased CO₂ ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp 'Macrocystis pyrifera' (Laminariales, Phaeophyceae) |
title_sort |
ocean acidification and seaweed reproduction: increased co₂ ameliorates the negative effect of lowered ph on meiospore germination in the giant kelp 'macrocystis pyrifera' (laminariales, phaeophyceae) |
publisher |
Wiley-Blackwell Publishing Ltd |
publishDate |
2012 |
url |
https://hdl.handle.net/1959.11/15833 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
10.1111/j.1365-2486.2011.02594.x https://hdl.handle.net/1959.11/15833 une:16070 |
_version_ |
1775354029009797120 |