Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry
While burial diagenetic processes of tropical corals are well investigated, current knowledge about factors initiating early diagenesis remains fragmentary. In the present study, we focus on recent Porites microatolls, growing in the intertidal zone. This growth form represents a model organism for...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-12-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/article/10.3389/feart.2019.00304/full |
| _version_ | 1819114361897091072 |
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| author | Stefan Krause Volker Liebetrau Gernot Nehrke Timo Damm Sebastian Büsse Thomas Leipe Angela Vogts Stanislav N. Gorb Anton Eisenhauer |
| author_facet | Stefan Krause Volker Liebetrau Gernot Nehrke Timo Damm Sebastian Büsse Thomas Leipe Angela Vogts Stanislav N. Gorb Anton Eisenhauer |
| author_sort | Stefan Krause |
| collection | DOAJ |
| description | While burial diagenetic processes of tropical corals are well investigated, current knowledge about factors initiating early diagenesis remains fragmentary. In the present study, we focus on recent Porites microatolls, growing in the intertidal zone. This growth form represents a model organism for elevated sea surface temperatures (SSTs) and provides important but rare archives for changes close to the seawater/atmosphere interface with exceptional precision on sea level reconstruction. As other coral growth forms, microatolls are prone to the colonization by endolithic green algae. In this case, the algae can facilitate earliest diagenetic alteration of the coral skeleton. Algae metabolic activity not only results in secondary coral porosity due to boring activities, but may also initiate reprecipitation of secondary aragonite within coral pore space, a process not exclusively restricted to microatoll settings. In the samples of this initial study, we quantified a mass transfer from primary to secondary aragonite of around 4% within endolithic green algae bands. Using δ18O, δ13C, Sr/Ca, U/Ca, Mg/Ca, and Li/Mg systematics suggests that the secondary aragonite precipitation followed abiotic precipitation principles. According to their individual distribution coefficients, the different isotope and element ratios showed variable sensitivity to the presence of secondary aragonite in bulk samples, with implications for microatoll-based SST reconstructions. The secondary precipitates formed on an organic template, presumably originating from endolithic green algae activity. Based on laboratory experiments with the green algae Ostreobium quekettii, we propose a conceptual model that secondary aragonite formation is potentially accelerated by an active intracellular calcium transport through the algal thallus from the location of dissolution into coral pore spaces. The combined high-resolution imaging and geochemical approach applied in this study shows that endolithic algae can possibly act as a main driver for earliest diagenesis of coral aragonite starting already during a coral’s life span. |
| first_indexed | 2024-12-22T04:44:05Z |
| format | Article |
| id | doaj.art-ed78c619fd1b4b9fb74f1a317d3432d1 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-22T04:44:05Z |
| publishDate | 2019-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-ed78c619fd1b4b9fb74f1a317d3432d12022-12-21T18:38:40ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632019-12-01710.3389/feart.2019.00304451387Endolithic Algae Affect Modern Coral Carbonate Morphology and ChemistryStefan Krause0Volker Liebetrau1Gernot Nehrke2Timo Damm3Sebastian Büsse4Thomas Leipe5Angela Vogts6Stanislav N. Gorb7Anton Eisenhauer8GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyAlfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanySection Biomedical Imaging, Department of Diagnostic Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Kiel, GermanyFunctional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, GermanyLeibniz Institute for Baltic Sea Research, Warnemünde, GermanyLeibniz Institute for Baltic Sea Research, Warnemünde, GermanyFunctional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyWhile burial diagenetic processes of tropical corals are well investigated, current knowledge about factors initiating early diagenesis remains fragmentary. In the present study, we focus on recent Porites microatolls, growing in the intertidal zone. This growth form represents a model organism for elevated sea surface temperatures (SSTs) and provides important but rare archives for changes close to the seawater/atmosphere interface with exceptional precision on sea level reconstruction. As other coral growth forms, microatolls are prone to the colonization by endolithic green algae. In this case, the algae can facilitate earliest diagenetic alteration of the coral skeleton. Algae metabolic activity not only results in secondary coral porosity due to boring activities, but may also initiate reprecipitation of secondary aragonite within coral pore space, a process not exclusively restricted to microatoll settings. In the samples of this initial study, we quantified a mass transfer from primary to secondary aragonite of around 4% within endolithic green algae bands. Using δ18O, δ13C, Sr/Ca, U/Ca, Mg/Ca, and Li/Mg systematics suggests that the secondary aragonite precipitation followed abiotic precipitation principles. According to their individual distribution coefficients, the different isotope and element ratios showed variable sensitivity to the presence of secondary aragonite in bulk samples, with implications for microatoll-based SST reconstructions. The secondary precipitates formed on an organic template, presumably originating from endolithic green algae activity. Based on laboratory experiments with the green algae Ostreobium quekettii, we propose a conceptual model that secondary aragonite formation is potentially accelerated by an active intracellular calcium transport through the algal thallus from the location of dissolution into coral pore spaces. The combined high-resolution imaging and geochemical approach applied in this study shows that endolithic algae can possibly act as a main driver for earliest diagenesis of coral aragonite starting already during a coral’s life span.https://www.frontiersin.org/article/10.3389/feart.2019.00304/fullearly diagenesissecondary precipitationabiogenic aragoniteelement ratiosea surface temperatureendolithic algae |
| spellingShingle | Stefan Krause Volker Liebetrau Gernot Nehrke Timo Damm Sebastian Büsse Thomas Leipe Angela Vogts Stanislav N. Gorb Anton Eisenhauer Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry Frontiers in Earth Science early diagenesis secondary precipitation abiogenic aragonite element ratio sea surface temperature endolithic algae |
| title | Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry |
| title_full | Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry |
| title_fullStr | Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry |
| title_full_unstemmed | Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry |
| title_short | Endolithic Algae Affect Modern Coral Carbonate Morphology and Chemistry |
| title_sort | endolithic algae affect modern coral carbonate morphology and chemistry |
| topic | early diagenesis secondary precipitation abiogenic aragonite element ratio sea surface temperature endolithic algae |
| url | https://www.frontiersin.org/article/10.3389/feart.2019.00304/full |
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