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The Global Coral Reef Monitoring Network released Status of Coral Reefs of the World: 2025, its seventh and most comprehensive edition, on 31 August 2026.
Average global hard coral cover has fallen from about 30.2% in the 1980-2009 reference period to about 27.3% in 2020-2024, a relative decline of roughly 9.5%.
The report's central warning is about timing rather than totals: the gap between mass bleaching events has narrowed to about five to six years, from decades earlier, leaving reefs too little time to recover.
Of the ten GCRMN regions, four are in long-term decline, four show no net change and two are increasing against the reference period.
The assessment rests on 21.1 million observations from 87,299 surveys at 36,886 reef sites across 124 countries and territories, spanning more than four decades of data.
A coral is a colony of polyps, and inside the tissues of each polyp live single-celled algae called zooxanthellae. The algae photosynthesise and pass most of the food they make to the coral, and in return get shelter and nutrients; they also supply the colour. Under heat stress the algae start producing reactive oxygen species that harm the host, and the polyp expels them. What is left is a translucent tissue over a white calcium-carbonate skeleton, which is the bleached appearance. A bleached coral is starving, not dead, and can recolonise with algae if the stress passes soon enough. This is why the interval between events matters more than the severity of any single one: recovery needs years of undisturbed conditions, and a five-year gap does not supply them.
Simple Analogy: The coral has evicted the tenant that pays its rent, and can survive only if the tenant returns quickly.
First global bleaching event; bleaching-level heat stress affected about 21% of the world's reef area
Second global bleaching event; about 37% of reef area affected
Third global bleaching event; about 68% of reef area affected
NOAA and ICRI confirm the fourth global bleaching event
Heat stress at bleaching level reaches about 84% of the world's reef area across 82 countries, territories and economies, making this the most intense event on record
GCRMN releases the seventh Status of Coral Reefs of the World report, covering data to 2024
Operational monitoring network of ICRI; compiles national and regional reef data into the Status of Coral Reefs of the World series, supported by the Australian Institute of Marine Science and the Government of Monaco
Informal partnership of governments, organisations and scientists for reef conservation; jointly confirmed the fourth global bleaching event with NOAA
Supports GCRMN and runs Australia's long-term reef monitoring programme, whose findings on the Great Barrier Reef feed the global assessment
The Gulf of Mannar, the Gulf of Kachchh, Lakshadweep and the Andaman and Nicobar Islands are India's principal coral reef regions, and all four sit in the Indian Ocean basin covered by the global assessment
Scleractinian (reef-building) corals are protected under Schedule I of the Wild Life (Protection) Act, 1972, the highest level of protection in Indian law
India has examples of fringing reefs in the Gulf of Mannar, atolls in Lakshadweep and fringing and barrier formations in the Andaman and Nicobar Islands, which is why the Indian coast is used as a teaching example of reef morphology
Reefs buffer coastlines against wave energy and support fisheries, so their decline is a coastal-hazard and livelihood question as much as a biodiversity one
GS Paper 3 > Conservation, environmental pollution and degradation; GS Paper 1 > Salient features of world physical geography
General Awareness > Environment and Current Affairs
"Biorock technology" is talked about in which one of the following situations?
Answer: Restoration of damaged coral reefs
Single-celled symbiotic algae living in coral tissue that supply most of the coral's food through photosynthesis and give it its colour
The proportion of the reef surface occupied by living reef-building corals, the standard metric used to track reef condition over time
A prolonged period of unusually high sea temperature, the immediate trigger for mass bleaching events
A period in which bleaching-level heat stress occurs across reefs in multiple ocean basins; four have been recorded, in 1998, 2010, 2014-17 and from 2023