Cargando…

Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral

Atoll islands are small, low-lying and highly vulnerable to sea level rise (SLR). Because these islands are fully composed of the skeletons from coral reef creatures, the healthy coral ecosystem plays a pivotal role in island resilience against SLR. The environmental deterioration of reefs caused by...

Descripción completa

Detalles Bibliográficos
Autores principales: Nakamura, Nobuko, Kayanne, Hajime, Takahashi, Yoshio, Sunamura, Michinari, Hosoi, Go, Yamano, Hiroya
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7193606/
https://www.ncbi.nlm.nih.gov/pubmed/32355177
http://dx.doi.org/10.1038/s41598-020-63578-4
_version_ 1783528225923661824
author Nakamura, Nobuko
Kayanne, Hajime
Takahashi, Yoshio
Sunamura, Michinari
Hosoi, Go
Yamano, Hiroya
author_facet Nakamura, Nobuko
Kayanne, Hajime
Takahashi, Yoshio
Sunamura, Michinari
Hosoi, Go
Yamano, Hiroya
author_sort Nakamura, Nobuko
collection PubMed
description Atoll islands are small, low-lying and highly vulnerable to sea level rise (SLR). Because these islands are fully composed of the skeletons from coral reef creatures, the healthy coral ecosystem plays a pivotal role in island resilience against SLR. The environmental deterioration of reefs caused by increases in the human population has been recently reported, but the timing and process are unknown. We investigated the annual black bands in a coral boring core from Fongafale Island, the capital of Tuvalu, which is a symbolic atoll country that is being submerged due to SLR. The iron redox state and microbial gene segments in the coral skeleton might be new environmental indicators that reveal the linkage between anthropogenic activity and coral reef ecosystems. Our findings provide the first demonstration that iron sulfide has formed concentrated black layers since 1991 under the seasonal anoxic conditions inside coral annual bands. Since the 1990s, increasing human activity and domestic waste-induced eutrophication has promoted sludge and/or turf algae proliferation with the subsequent seasonal destruction, resulting in sulfate reduction by anaerobic bacteria. With the recent climate variability, these anthropogenic effects have induced the mass mortality of branching corals, deteriorated the coral reef ecosystem and deprived the resilience of the island against SLR.
format Online
Article
Text
id pubmed-7193606
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-71936062020-05-08 Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral Nakamura, Nobuko Kayanne, Hajime Takahashi, Yoshio Sunamura, Michinari Hosoi, Go Yamano, Hiroya Sci Rep Article Atoll islands are small, low-lying and highly vulnerable to sea level rise (SLR). Because these islands are fully composed of the skeletons from coral reef creatures, the healthy coral ecosystem plays a pivotal role in island resilience against SLR. The environmental deterioration of reefs caused by increases in the human population has been recently reported, but the timing and process are unknown. We investigated the annual black bands in a coral boring core from Fongafale Island, the capital of Tuvalu, which is a symbolic atoll country that is being submerged due to SLR. The iron redox state and microbial gene segments in the coral skeleton might be new environmental indicators that reveal the linkage between anthropogenic activity and coral reef ecosystems. Our findings provide the first demonstration that iron sulfide has formed concentrated black layers since 1991 under the seasonal anoxic conditions inside coral annual bands. Since the 1990s, increasing human activity and domestic waste-induced eutrophication has promoted sludge and/or turf algae proliferation with the subsequent seasonal destruction, resulting in sulfate reduction by anaerobic bacteria. With the recent climate variability, these anthropogenic effects have induced the mass mortality of branching corals, deteriorated the coral reef ecosystem and deprived the resilience of the island against SLR. Nature Publishing Group UK 2020-04-30 /pmc/articles/PMC7193606/ /pubmed/32355177 http://dx.doi.org/10.1038/s41598-020-63578-4 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Nakamura, Nobuko
Kayanne, Hajime
Takahashi, Yoshio
Sunamura, Michinari
Hosoi, Go
Yamano, Hiroya
Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral
title Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral
title_full Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral
title_fullStr Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral
title_full_unstemmed Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral
title_short Anthropogenic Anoxic History of the Tuvalu Atoll Recorded as Annual Black Bands in Coral
title_sort anthropogenic anoxic history of the tuvalu atoll recorded as annual black bands in coral
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7193606/
https://www.ncbi.nlm.nih.gov/pubmed/32355177
http://dx.doi.org/10.1038/s41598-020-63578-4
work_keys_str_mv AT nakamuranobuko anthropogenicanoxichistoryofthetuvaluatollrecordedasannualblackbandsincoral
AT kayannehajime anthropogenicanoxichistoryofthetuvaluatollrecordedasannualblackbandsincoral
AT takahashiyoshio anthropogenicanoxichistoryofthetuvaluatollrecordedasannualblackbandsincoral
AT sunamuramichinari anthropogenicanoxichistoryofthetuvaluatollrecordedasannualblackbandsincoral
AT hosoigo anthropogenicanoxichistoryofthetuvaluatollrecordedasannualblackbandsincoral
AT yamanohiroya anthropogenicanoxichistoryofthetuvaluatollrecordedasannualblackbandsincoral