What it is
NOAA Coral Reef Watch is a satellite monitoring system that tracks sea surface temperatures and predicts coral bleaching risk worldwide in near-real-time. The platform provides daily-updated global maps of sea surface temperature anomalies, bleaching alert levels (from Watch to Alert Level 2), and degree heating week accumulations. Data is freely available to researchers, marine park managers, and the public through their website and API.
Why we picked this
Early warning saves reefs. When marine park managers know a bleaching event is approaching, they can restrict diving and fishing activity, deploy shade structures, and prepare emergency interventions. Coral Reef Watch is the global standard for this early warning: their 5 km resolution satellite data covers every reef on Earth, and their four-level alert system is used by conservation organizations in over 100 countries. The 2023-2024 global bleaching event was tracked in real-time by this system.
Key takeaways
- The system uses satellite-derived sea surface temperatures at 5 km resolution, updated daily, covering every coral reef on the planet.
- Degree Heating Weeks (DHW) above 4 correlate with significant bleaching, and DHW above 8 correlate with widespread mortality, providing clear decision thresholds.
- The 2023-2024 global bleaching event, the fourth on record, affected 77% of the world's reef areas, all tracked and predicted by this system weeks in advance.