Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan

Abstract Coral bleaching occurs when symbiotic dinoflagellate algae leave corals due to warming surface waters. Since the early 1980s, the number and intensity of coral bleaching events have significantly risen globally, and many coral reefs are concerned to undergo irreversible phase shifts due to...

Full description

Saved in:
Bibliographic Details
Main Authors: Sayaka Yasunaka, Haruko Kurihara, Takeshi Doi
Format: Article
Language:English
Published: SpringerOpen 2025-01-01
Series:Progress in Earth and Planetary Science
Subjects:
Online Access:https://doi.org/10.1186/s40645-024-00673-4
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832585327746744320
author Sayaka Yasunaka
Haruko Kurihara
Takeshi Doi
author_facet Sayaka Yasunaka
Haruko Kurihara
Takeshi Doi
author_sort Sayaka Yasunaka
collection DOAJ
description Abstract Coral bleaching occurs when symbiotic dinoflagellate algae leave corals due to warming surface waters. Since the early 1980s, the number and intensity of coral bleaching events have significantly risen globally, and many coral reefs are concerned to undergo irreversible phase shifts due to global warming. In this study, we examine spatiotemporal variations and relationships of high-temperature events, high-temperature anomaly events, and coral bleaching around the Ryukyu Islands, Japan. We also explore the correlation between these occurrences and the large-scale climate variability, El Niño–Southern Oscillation and Indian Ocean Dipole. More than 99% of the high-temperature events occurred from June to October, and more than 80% occurred from July to September, whereas high-temperature anomaly events occurred all year round. Corresponding with high-temperature events, more than 10% of the data reported overall bleaching, and more than 25% reported partial bleaching from June to October. Over 40% of data reported bleaching in August, of which 50% of these reports were categorized as overall bleaching and the remainder as partial. The spatial distribution of coral bleaching also corresponded better with high-temperature events than high-temperature anomaly events. In 2016, extensive and severe coral bleaching was reported around the Okinawa, Miyako, and Yaeyama Islands, where intense high-temperature events had occurred. The central-to-eastern equatorial Pacific displayed a negative sea surface temperature anomaly, and the eastern Indian Ocean did a positive anomaly following high-temperature events near the Ryukyu Islands. These findings indicated that the high-temperature events around the Ryukyu Islands show correlation with La Niña and a negative Indian Ocean Dipole. If the cumulative temperature of high-temperature events exceeds 56 °C-days every three years in the late 2030s, then the corals around the Ryukyu Islands will suffer high mortality within 20 years.
format Article
id doaj-art-f864dc00566e480ab4d73da7c30d4406
institution Kabale University
issn 2197-4284
language English
publishDate 2025-01-01
publisher SpringerOpen
record_format Article
series Progress in Earth and Planetary Science
spelling doaj-art-f864dc00566e480ab4d73da7c30d44062025-01-26T12:57:43ZengSpringerOpenProgress in Earth and Planetary Science2197-42842025-01-0112111010.1186/s40645-024-00673-4Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, JapanSayaka Yasunaka0Haruko Kurihara1Takeshi Doi2Graduate School of Science, Tohoku UniversityFaculty of Science, University of the RyukyusDivision Application Laboratory, Research Institute for Value-Added-Information Generation Organization, Japan Agency for Marine-Earth Science and TechnologyAbstract Coral bleaching occurs when symbiotic dinoflagellate algae leave corals due to warming surface waters. Since the early 1980s, the number and intensity of coral bleaching events have significantly risen globally, and many coral reefs are concerned to undergo irreversible phase shifts due to global warming. In this study, we examine spatiotemporal variations and relationships of high-temperature events, high-temperature anomaly events, and coral bleaching around the Ryukyu Islands, Japan. We also explore the correlation between these occurrences and the large-scale climate variability, El Niño–Southern Oscillation and Indian Ocean Dipole. More than 99% of the high-temperature events occurred from June to October, and more than 80% occurred from July to September, whereas high-temperature anomaly events occurred all year round. Corresponding with high-temperature events, more than 10% of the data reported overall bleaching, and more than 25% reported partial bleaching from June to October. Over 40% of data reported bleaching in August, of which 50% of these reports were categorized as overall bleaching and the remainder as partial. The spatial distribution of coral bleaching also corresponded better with high-temperature events than high-temperature anomaly events. In 2016, extensive and severe coral bleaching was reported around the Okinawa, Miyako, and Yaeyama Islands, where intense high-temperature events had occurred. The central-to-eastern equatorial Pacific displayed a negative sea surface temperature anomaly, and the eastern Indian Ocean did a positive anomaly following high-temperature events near the Ryukyu Islands. These findings indicated that the high-temperature events around the Ryukyu Islands show correlation with La Niña and a negative Indian Ocean Dipole. If the cumulative temperature of high-temperature events exceeds 56 °C-days every three years in the late 2030s, then the corals around the Ryukyu Islands will suffer high mortality within 20 years.https://doi.org/10.1186/s40645-024-00673-4Coral bleachingSea surface temperatureDegree heating weekMarine heatwaveEl Niño–Southern OscillationIndian Ocean Dipole
spellingShingle Sayaka Yasunaka
Haruko Kurihara
Takeshi Doi
Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan
Progress in Earth and Planetary Science
Coral bleaching
Sea surface temperature
Degree heating week
Marine heatwave
El Niño–Southern Oscillation
Indian Ocean Dipole
title Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan
title_full Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan
title_fullStr Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan
title_full_unstemmed Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan
title_short Spatiotemporal variation of high-temperature events and its relation to coral bleaching in the Ryukyu Islands, Japan
title_sort spatiotemporal variation of high temperature events and its relation to coral bleaching in the ryukyu islands japan
topic Coral bleaching
Sea surface temperature
Degree heating week
Marine heatwave
El Niño–Southern Oscillation
Indian Ocean Dipole
url https://doi.org/10.1186/s40645-024-00673-4
work_keys_str_mv AT sayakayasunaka spatiotemporalvariationofhightemperatureeventsanditsrelationtocoralbleachingintheryukyuislandsjapan
AT harukokurihara spatiotemporalvariationofhightemperatureeventsanditsrelationtocoralbleachingintheryukyuislandsjapan
AT takeshidoi spatiotemporalvariationofhightemperatureeventsanditsrelationtocoralbleachingintheryukyuislandsjapan