Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process
Calcifying macroalgae contribute significantly to the structure and function of tropical marine ecosystems. Their calcification and photosynthetic processes are not well understood despite their critical role in marine carbon cycles and high vulnerability to environmental changes. This study aims to...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/10/11/2537 |
| _version_ | 1797508635773894656 |
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| author | Pimchanok Buapet Sutinee Sinutok |
| author_facet | Pimchanok Buapet Sutinee Sinutok |
| author_sort | Pimchanok Buapet |
| collection | DOAJ |
| description | Calcifying macroalgae contribute significantly to the structure and function of tropical marine ecosystems. Their calcification and photosynthetic processes are not well understood despite their critical role in marine carbon cycles and high vulnerability to environmental changes. This study aims to provide a better understanding of the macroalgal calcification process, focusing on its relevance concerning seawater carbonate chemistry and its relationship to photosynthesis in three dominant calcified macroalgae in Thailand, <i>Padina boryana</i>, <i>Halimeda macroloba</i> and <i>Halimeda opuntia</i>. Morphological and microstructural attributes of the three macroalgae were analyzed and subsequently linked to their calcification rates and responses to inhibition of photosynthesis. In the first experiment, seawater pH, total alkalinity and total dissolved inorganic carbon were measured after incubation of the macroalgae in the light and after equilibration of the seawater with air. Estimations of carbon uptake into photosynthesis and calcification and carbon release into air were obtained thereafter. Our results provide evidence that calcification of the three calcified macroalgae is a potential source of CO<sub>2</sub>, where calcification by <i>H. opuntia</i> and <i>H. macroloba</i> leads to a greater release of CO<sub>2</sub> per biomass weight than <i>P. boryana</i>. Nevertheless, this capacity is expected to vary on a diurnal basis, as the second experiment indicates that calcification is highly coupled to photosynthetic activity. Lower pH as a result of inhibited photosynthesis under darkness imposes more negative effects on <i>H. opuntia</i> and <i>H. macroloba</i> than on <i>P. boryana</i>, implying that they are more sensitive to acidification. These effects were worsened when photosynthesis was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, highlighting the significance of photosynthetic electron transport-dependent processes. Our findings suggest that estimations of the amount of carbon stored in the vegetated marine ecosystems should account for macroalgal calcification as a potential carbon source while considering diurnal variations in photosynthesis and seawater pH in a natural setting. |
| first_indexed | 2024-03-10T05:06:42Z |
| format | Article |
| id | doaj.art-172bed85ad954ad0b998be8cbdcb7795 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-10T05:06:42Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-172bed85ad954ad0b998be8cbdcb77952023-11-23T01:07:26ZengMDPI AGPlants2223-77472021-11-011011253710.3390/plants10112537Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic ProcessPimchanok Buapet0Sutinee Sinutok1Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai 90110, Songkhla, ThailandCoastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai 90110, Songkhla, ThailandCalcifying macroalgae contribute significantly to the structure and function of tropical marine ecosystems. Their calcification and photosynthetic processes are not well understood despite their critical role in marine carbon cycles and high vulnerability to environmental changes. This study aims to provide a better understanding of the macroalgal calcification process, focusing on its relevance concerning seawater carbonate chemistry and its relationship to photosynthesis in three dominant calcified macroalgae in Thailand, <i>Padina boryana</i>, <i>Halimeda macroloba</i> and <i>Halimeda opuntia</i>. Morphological and microstructural attributes of the three macroalgae were analyzed and subsequently linked to their calcification rates and responses to inhibition of photosynthesis. In the first experiment, seawater pH, total alkalinity and total dissolved inorganic carbon were measured after incubation of the macroalgae in the light and after equilibration of the seawater with air. Estimations of carbon uptake into photosynthesis and calcification and carbon release into air were obtained thereafter. Our results provide evidence that calcification of the three calcified macroalgae is a potential source of CO<sub>2</sub>, where calcification by <i>H. opuntia</i> and <i>H. macroloba</i> leads to a greater release of CO<sub>2</sub> per biomass weight than <i>P. boryana</i>. Nevertheless, this capacity is expected to vary on a diurnal basis, as the second experiment indicates that calcification is highly coupled to photosynthetic activity. Lower pH as a result of inhibited photosynthesis under darkness imposes more negative effects on <i>H. opuntia</i> and <i>H. macroloba</i> than on <i>P. boryana</i>, implying that they are more sensitive to acidification. These effects were worsened when photosynthesis was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, highlighting the significance of photosynthetic electron transport-dependent processes. Our findings suggest that estimations of the amount of carbon stored in the vegetated marine ecosystems should account for macroalgal calcification as a potential carbon source while considering diurnal variations in photosynthesis and seawater pH in a natural setting.https://www.mdpi.com/2223-7747/10/11/2537blue carbonclimate changemacroalgaeecophysiology |
| spellingShingle | Pimchanok Buapet Sutinee Sinutok Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process Plants blue carbon climate change macroalgae ecophysiology |
| title | Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process |
| title_full | Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process |
| title_fullStr | Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process |
| title_full_unstemmed | Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process |
| title_short | Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process |
| title_sort | calcification in three common calcified algae from phuket thailand potential relevance on seawater carbonate chemistry and link to photosynthetic process |
| topic | blue carbon climate change macroalgae ecophysiology |
| url | https://www.mdpi.com/2223-7747/10/11/2537 |
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