Oceans can also experience heatwaves. A marine heatwave refers to a phenomenon characterized by a warm period at sea, and from the year1982 to 2016, the number of marine heatwaves has increased twofold.
What is a marine heatwave though?
Marine heatwaves cannot be defined unlike those on land since there is no fixed temperature indicating a marine heatwave because temperatures in oceans differ depending on seasons and geographic locations with durations that range from days to several months or years.
Effects of damages
- Coral reefs and kelp: Coral and kelp face threats from marine heatwaves because they are stationary living organisms.
- Marine animals: A large number of sea lion babies died from starvation because of a marine wave named Pacific “Blob.”
- Storms: It has been observed that stronger storms occur in warmer seas in Arabian Sea and Bay of Bengal.
- Monsoon: Marine heatwaves negatively affected monsoon patterns and in places distant from the sea, in central India.
Current Situation in India
The Indian agency INCOIS issued a marine heatwave warning to 6 basins of the country with the most affected Arabian Sea on April 20, 2026, which is one of the fastest warming tropical basins.
A Record Year
Marine heatwaves covered 82 percent of the oceans, and global sea temperatures reached a record 20.86°C in June 2026, a summary based on Copernicus data says.
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