01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-05-0196 |
| Title of Abstract | Sea Surface Temperature Rise and Marine Heatwave Intensification Over Coral Reefs in the Indian Ocean |
| Authors | Bilwa Anil Giram, Roxy Mathew Koll, Aditi Deshpande* |
| Organisation | SPPU |
| Address | 54/1, Homkar Nagar, Solapur Solapur, Maharashtra, India Pincode: 413002 E-mail: bilwagiram@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | Coral reefs are among the most diverse ecosystems globally but are increasingly threatened by rising ocean temperatures. In the North Indian Ocean, reefs remain critically understudied, with scarce long-term monitoring and limited recent coral cover data. To address this gap, we examine long-term sea surface temperature (SST) trends and marine heatwave (MHW) patterns across five key reef regions: the Andaman and Nicobar Islands, the Lakshadweep Islands, the Western Coast, the Gulf of Mannar, and the Gulf of Kutch. We analyze three SST datasets⿿HadISST (reconstructed), ERA5 (reanalysis), and OISST (satellite observations)⿿to assess summertime SST trends over different periods. HadISST (123 years) revealed the lowest warming trend per decade, ERA5 (84 years) showed a higher rise, while OISST (43 years) indicated the steepest increase, highlighting accelerated recent warming linked to anthropogenic climate change. Regionally, the Gulf of Mannar showed the lowest warming trend, while the Gulf of Kutch exhibited the highest. Notably, HadISST recorded a 1.26 °C rise in the Gulf of Kutch over 123 years. MHW analysis revealed dataset-dependent differences, with ERA5 recording fewer MHW days annually than OISST. Using OISST, the Andaman and Nicobar Islands showed the greatest increase in MHW days per decade. Across all regions, the mean number of MHW days during 2015⿿2024 was 144.4 days in ERA5 and 203.6 days in OISST, suggesting a near semi-permanent MHW state in recent years. Our results highlight the urgency of sustained monitoring of North Indian Ocean coral reefs, as warming and intensifying MHWs increasingly threaten reef health and resilience. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Coral reefs, North Indian Ocean, Sea Surface Temperature (SST), Marine Heatwaves (MHWs), Climate change, Anthropogenic warming, Andaman and Nicobar Islands |
| For Awards | no |