Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions
Calcification in reef corals and coral reefs is widely measured using the alkalinity depletion method which is based on the fact that two protons are produced for every mole of CaCO3 precipitated. This assumption was tested by measuring the total alkalinity (TA) flux and Ca2+ flux of isolated compon...
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ftdoajarticles:oai:doaj.org/article:29ae5355071842e8970fa51d6769ad3b 2023-10-01T03:58:39+02:00 Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions Liana J.A. Murillo Paul L. Jokiel Marlin J. Atkinson 2014-02-01T00:00:00Z https://doi.org/10.7717/peerj.249 https://doaj.org/article/29ae5355071842e8970fa51d6769ad3b EN eng PeerJ Inc. https://peerj.com/articles/249.pdf https://peerj.com/articles/249/ https://doaj.org/toc/2167-8359 doi:10.7717/peerj.249 2167-8359 https://doaj.org/article/29ae5355071842e8970fa51d6769ad3b PeerJ, Vol 2, p e249 (2014) Coral reef Biogeochemistry Alkalinity anomaly Reef ecology Alkalinity flux Ocean acidification Medicine R article 2014 ftdoajarticles https://doi.org/10.7717/peerj.249 2023-09-03T00:45:47Z Calcification in reef corals and coral reefs is widely measured using the alkalinity depletion method which is based on the fact that two protons are produced for every mole of CaCO3 precipitated. This assumption was tested by measuring the total alkalinity (TA) flux and Ca2+ flux of isolated components (corals, alga, sediment and plankton) in reference to that of a mixed-community. Experiments were conducted in a flume under natural conditions of sunlight, nutrients, plankton and organic matter. A realistic hydrodynamic regime was provided. Groups of corals were run separately and in conjunction with the other reef components in a mixed-community. The TA flux to Ca2+ flux ratio (ΔTA: ΔCa2+) was consistently higher in the coral-only run (2.06 ± 0.19) than in the mixed-community run (1.60 ± 0.14, p-value = 0.011). The pH was higher and more stable in the mixed-community run (7.94 ± 0.03 vs. 7.52 ± 0.07, p-value = 3 × 10−5). Aragonite saturation state (Ωarag) was also higher in the mixed-community run (2.51 ± 0.2 vs. 1.12 ± 0.14, p-value = 2 × 10−6). The sediment-only run revealed that sediment is the source of TA that can account for the lower ΔTA: ΔCa2+ ratio in the mixed-community run. The macroalgae-only run showed that algae were responsible for the increased pH in the mixed-community run. Corals growing in a mixed-community will experience an environment that is more favorable to calcification (higher daytime pH due to algae photosynthesis, additional TA and inorganic carbon from sediments, higher Ωarag). A paradox is that the alkalinity depletion method will yield a lower net calcification for a mixed-community versus a coral-only community due to TA recycling, even though the corals may be calcifying at a higher rate due to a more optimal environment. Article in Journal/Newspaper Ocean acidification Directory of Open Access Journals: DOAJ Articles PeerJ 2 e249 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Coral reef Biogeochemistry Alkalinity anomaly Reef ecology Alkalinity flux Ocean acidification Medicine R |
spellingShingle |
Coral reef Biogeochemistry Alkalinity anomaly Reef ecology Alkalinity flux Ocean acidification Medicine R Liana J.A. Murillo Paul L. Jokiel Marlin J. Atkinson Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
topic_facet |
Coral reef Biogeochemistry Alkalinity anomaly Reef ecology Alkalinity flux Ocean acidification Medicine R |
description |
Calcification in reef corals and coral reefs is widely measured using the alkalinity depletion method which is based on the fact that two protons are produced for every mole of CaCO3 precipitated. This assumption was tested by measuring the total alkalinity (TA) flux and Ca2+ flux of isolated components (corals, alga, sediment and plankton) in reference to that of a mixed-community. Experiments were conducted in a flume under natural conditions of sunlight, nutrients, plankton and organic matter. A realistic hydrodynamic regime was provided. Groups of corals were run separately and in conjunction with the other reef components in a mixed-community. The TA flux to Ca2+ flux ratio (ΔTA: ΔCa2+) was consistently higher in the coral-only run (2.06 ± 0.19) than in the mixed-community run (1.60 ± 0.14, p-value = 0.011). The pH was higher and more stable in the mixed-community run (7.94 ± 0.03 vs. 7.52 ± 0.07, p-value = 3 × 10−5). Aragonite saturation state (Ωarag) was also higher in the mixed-community run (2.51 ± 0.2 vs. 1.12 ± 0.14, p-value = 2 × 10−6). The sediment-only run revealed that sediment is the source of TA that can account for the lower ΔTA: ΔCa2+ ratio in the mixed-community run. The macroalgae-only run showed that algae were responsible for the increased pH in the mixed-community run. Corals growing in a mixed-community will experience an environment that is more favorable to calcification (higher daytime pH due to algae photosynthesis, additional TA and inorganic carbon from sediments, higher Ωarag). A paradox is that the alkalinity depletion method will yield a lower net calcification for a mixed-community versus a coral-only community due to TA recycling, even though the corals may be calcifying at a higher rate due to a more optimal environment. |
format |
Article in Journal/Newspaper |
author |
Liana J.A. Murillo Paul L. Jokiel Marlin J. Atkinson |
author_facet |
Liana J.A. Murillo Paul L. Jokiel Marlin J. Atkinson |
author_sort |
Liana J.A. Murillo |
title |
Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
title_short |
Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
title_full |
Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
title_fullStr |
Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
title_full_unstemmed |
Alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
title_sort |
alkalinity to calcium flux ratios for corals and coral reef communities: variances between isolated and community conditions |
publisher |
PeerJ Inc. |
publishDate |
2014 |
url |
https://doi.org/10.7717/peerj.249 https://doaj.org/article/29ae5355071842e8970fa51d6769ad3b |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
PeerJ, Vol 2, p e249 (2014) |
op_relation |
https://peerj.com/articles/249.pdf https://peerj.com/articles/249/ https://doaj.org/toc/2167-8359 doi:10.7717/peerj.249 2167-8359 https://doaj.org/article/29ae5355071842e8970fa51d6769ad3b |
op_doi |
https://doi.org/10.7717/peerj.249 |
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PeerJ |
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2 |
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e249 |
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1778531590654132224 |