NOAA Coral Reef Watch Satellite Bleaching Alert System (SBA)

NOAA Coral Reef Watch Satellite Bleaching Alert

5-km Satellite Regional Virtual Stations

Bleaching or no bleaching, please report to your regional network or to Coral Reef Watch!

Alert Changes Summary

Based on data from 06 Apr 2025

No Stress

Watch

Warning

Alert Level 1

Alert Level 2

(↑) or (↓) indicates an increase or decrease in the heat stress level

Alerts are for reef regions, archipelagos or jurisdictions, not for individual data grid points


Pacific Ocean
Eastern Pacific
Clipperton Island, France	↑ Watch
Isla del Coco, Costa Rica	↑ Alert Level 1
Polynesia
Northern Cook Islands	↑ Warning
Micronesia
Western FSM	↑ Watch
Phoenix Islands, Kiribati	↑ Watch

Southeast Asia
Other Southeast Asia Stations
Northern Myanmar	↑ Watch
Northern Java	↑ Watch
Coral Triangle
East Kalimantan	↓ Watch
Maluku, Indonesia	↓ Watch

Australia
Great Barrier Reef
Southern Coral Sea Islands	↑ Alert Level 2
Other Australia Stations
North Western Australia	↓ Watch
Lord Howe Island, Australia	↓ Watch

Indian Ocean
Middle East
Al Wusta, Oman	↑ Watch
South Asia
Kerala, India	↑ Alert Level 1
Western Indian Ocean
Somalia	↑ Warning
Seychelles	↓ Watch
Glorioso Islands	↑ Alert Level 2

All Station Alert Levels

Google Earth KMZ

5-km Satellite Regional Virtual Station Bleaching Alert Details

Based on data from 06 Apr 2025



Clipperton Island, France	↑ Watch
Satellite Observations: (description)
Degree Heating Week	0.0°C-weeks
Coral Bleaching HotSpot	0.0°C
Sea Surface Temperature (SST)	28.8°C
SST Anomaly	0.5°C
Maximum Monthly Mean SST Climatology	28.8°C
Most Recent Alert Level Changes:
04/06/2025	Watch
10/30/2024	No Stress
10/23/2024	Watch
10/02/2024	No Stress
08/25/2024	Watch
Map and Gauge
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Isla del Coco, Costa Rica	↑ Alert Level 1
Satellite Observations: (description)
Degree Heating Week	4.1°C-weeks
Coral Bleaching HotSpot	1.7°C
Sea Surface Temperature (SST)	30.7°C
SST Anomaly	1.8°C
Maximum Monthly Mean SST Climatology	29.0°C
Most Recent Alert Level Changes:
04/06/2025	Alert Level 1
03/05/2025	Warning
02/26/2025	Watch
02/23/2025	No Stress
02/12/2025	Watch
Map and Gauge
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Northern Cook Islands	↑ Warning
Satellite Observations: (description)
Degree Heating Week	0.3°C-weeks
Coral Bleaching HotSpot	1.0°C
Sea Surface Temperature (SST)	30.1°C
SST Anomaly	1.0°C
Maximum Monthly Mean SST Climatology	29.3°C
Most Recent Alert Level Changes:
04/06/2025	Warning
09/18/2024	Watch
08/25/2024	No Stress
06/19/2024	Watch
03/03/2024	Alert Level 2
Map and Gauge
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Western FSM	↑ Watch
Satellite Observations: (description)
Degree Heating Week	0.0°C-weeks
Coral Bleaching HotSpot	0.1°C
Sea Surface Temperature (SST)	29.3°C
SST Anomaly	1.0°C
Maximum Monthly Mean SST Climatology	29.1°C
Most Recent Alert Level Changes:
04/06/2025	Watch
04/02/2025	No Stress
03/16/2025	Watch
02/19/2025	No Stress
11/24/2024	Watch
Map and Gauge
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Phoenix Islands, Kiribati	↑ Watch
Satellite Observations: (description)
Degree Heating Week	0.0°C-weeks
Coral Bleaching HotSpot	0.3°C
Sea Surface Temperature (SST)	29.6°C
SST Anomaly	0.6°C
Maximum Monthly Mean SST Climatology	29.0°C
Most Recent Alert Level Changes:
04/06/2025	Watch
04/02/2025	No Stress
03/23/2025	Watch
12/22/2024	No Stress
12/08/2024	Watch
Map and Gauge
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Northern Myanmar	↑ Watch
Satellite Observations: (description)
Degree Heating Week	0.0°C-weeks
Coral Bleaching HotSpot	0.2°C
Sea Surface Temperature (SST)	29.8°C
SST Anomaly	1.4°C
Maximum Monthly Mean SST Climatology	29.3°C
Most Recent Alert Level Changes:
04/06/2025	Watch
12/01/2024	No Stress
11/13/2024	Watch
11/03/2024	Alert Level 1
10/13/2024	Warning
Map and Gauge
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Northern Java	↑ Watch
Satellite Observations: (description)
Degree Heating Week	0.0°C-weeks
Coral Bleaching HotSpot	0.1°C
Sea Surface Temperature (SST)	29.7°C
SST Anomaly	0.5°C
Maximum Monthly Mean SST Climatology	29.6°C
Most Recent Alert Level Changes:
04/06/2025	Watch
04/02/2025	No Stress
03/02/2025	Watch
01/01/2025	No Stress
12/08/2024	Watch
Map and Gauge
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East Kalimantan	↓ Watch
Satellite Observations: (description)
Degree Heating Week	0.3°C-weeks
Coral Bleaching HotSpot	0.6°C
Sea Surface Temperature (SST)	29.6°C
SST Anomaly	1.0°C
Maximum Monthly Mean SST Climatology	29.1°C
Most Recent Alert Level Changes:
04/06/2025	Watch
03/30/2025	Warning
12/25/2024	Watch
12/18/2024	Alert Level 1
12/11/2024	Watch
Map and Gauge
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Maluku, Indonesia	↓ Watch
Satellite Observations: (description)
Degree Heating Week	1.8°C-weeks
Coral Bleaching HotSpot	0.7°C
Sea Surface Temperature (SST)	29.7°C
SST Anomaly	0.9°C
Maximum Monthly Mean SST Climatology	29.1°C
Most Recent Alert Level Changes:
04/06/2025	Watch
03/30/2025	Warning
03/23/2025	Watch
03/16/2025	Warning
02/05/2025	Watch
Map and Gauge
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Southern Coral Sea Islands	↑ Alert Level 2
Satellite Observations: (description)
Degree Heating Week	8.0°C-weeks
Coral Bleaching HotSpot	0.8°C
Sea Surface Temperature (SST)	28.7°C
SST Anomaly	1.7°C
Maximum Monthly Mean SST Climatology	27.3°C
Most Recent Alert Level Changes:
04/06/2025	Alert Level 2
03/02/2025	Watch
02/19/2025	Alert Level 2
01/29/2025	Alert Level 1
01/15/2025	Warning
Map and Gauge
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North Western Australia	↓ Watch
Satellite Observations: (description)
Degree Heating Week	14.2°C-weeks
Coral Bleaching HotSpot	0.6°C
Sea Surface Temperature (SST)	30.6°C
SST Anomaly	0.7°C
Maximum Monthly Mean SST Climatology	29.9°C
Most Recent Alert Level Changes:
04/06/2025	Watch
02/23/2025	Alert Level 2
02/19/2025	Watch
12/15/2024	Alert Level 2
12/01/2024	Alert Level 1
Map and Gauge
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Lord Howe Island, Australia	↓ Watch
Satellite Observations: (description)
Degree Heating Week	1.8°C-weeks
Coral Bleaching HotSpot	0.1°C
Sea Surface Temperature (SST)	24.1°C
SST Anomaly	1.4°C
Maximum Monthly Mean SST Climatology	24.1°C
Most Recent Alert Level Changes:
04/06/2025	Watch
03/23/2025	Warning
02/16/2025	Watch
02/02/2025	Warning
12/15/2024	Watch
Map and Gauge
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Al Wusta, Oman	↑ Watch
Satellite Observations: (description)
Degree Heating Week	0.0°C-weeks
Coral Bleaching HotSpot	0.1°C
Sea Surface Temperature (SST)	27.3°C
SST Anomaly	1.4°C
Maximum Monthly Mean SST Climatology	27.8°C
Most Recent Alert Level Changes:
04/06/2025	Watch
12/15/2024	No Stress
12/01/2024	Watch
11/06/2024	Alert Level 1
10/20/2024	Warning
Map and Gauge
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Kerala, India	↑ Alert Level 1
Satellite Observations: (description)
Degree Heating Week	4.7°C-weeks
Coral Bleaching HotSpot	1.3°C
Sea Surface Temperature (SST)	31.0°C
SST Anomaly	1.5°C
Maximum Monthly Mean SST Climatology	29.5°C
Most Recent Alert Level Changes:
04/06/2025	Alert Level 1
03/12/2025	Warning
02/19/2025	Watch
12/22/2024	No Stress
10/27/2024	Watch
Map and Gauge
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Somalia	↑ Warning
Satellite Observations: (description)
Degree Heating Week	0.3°C-weeks
Coral Bleaching HotSpot	1.0°C
Sea Surface Temperature (SST)	29.9°C
SST Anomaly	1.3°C
Maximum Monthly Mean SST Climatology	28.8°C
Most Recent Alert Level Changes:
04/06/2025	Warning
03/23/2025	Watch
05/29/2024	No Stress
05/05/2024	Watch
04/14/2024	Alert Level 2
Map and Gauge
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Seychelles	↓ Watch
Satellite Observations: (description)
Degree Heating Week	6.2°C-weeks
Coral Bleaching HotSpot	0.8°C
Sea Surface Temperature (SST)	29.5°C
SST Anomaly	1.0°C
Maximum Monthly Mean SST Climatology	28.9°C
Most Recent Alert Level Changes:
04/06/2025	Watch
03/16/2025	Alert Level 1
03/02/2025	Warning
02/26/2025	Watch
02/12/2025	Warning
Map and Gauge
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Glorioso Islands	↑ Alert Level 2
Satellite Observations: (description)
Degree Heating Week	8.1°C-weeks
Coral Bleaching HotSpot	1.2°C
Sea Surface Temperature (SST)	30.0°C
SST Anomaly	1.3°C
Maximum Monthly Mean SST Climatology	28.9°C
Most Recent Alert Level Changes:
04/06/2025	Alert Level 2
03/02/2025	Alert Level 1
02/12/2025	Warning
02/09/2025	Watch
01/29/2025	Warning
Map and Gauge
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Summary Notes

No Stress	No heat stress	HS <= 0
Watch	Low heat stress	0 < HS < 1
Warning	Heat stress accumulating	HS >= 1 0 < DHW < 4
Alert Level 1	Bleaching expected	HS >= 1 4 <= DHW < 8
Alert Level 2	Significant bleaching expected; mortality likely	HS >= 1 DHW >= 8

Bleaching alerts are only generated when there is a stress level change for a station.
The alerts are generated for affected reef regions, archipelagos, and/or jurisdictions, not for individual data grid points.
Your bleaching observations (including observations of no bleaching) are greatly
appreciated. Observations can be sent to coralreefwatch@noaa.gov and/or entered online via Coral Reef Watch.
Should you have any questions or feedback on our Satellite Bleaching Alert email system, please send an email to coralreefwatch@noaa.gov.
To view, change (stations, email type, etc), or end your subscription, please visit the Coral Reef Watch Satellite Bleaching Alert website.
Please do not reply to this email address.

Disclaimer

07-Apr-2025

Eastern Pacific

Polynesia

Micronesia

Other Southeast Asia Stations

Coral Triangle

Great Barrier Reef

Other Australia Stations

Middle East

South Asia

Western Indian Ocean