Thailand’s coral reefs are losing their complex 3d structure as marine heat waves take their toll

A comprehensive new study of Thailand’s coral reefs has confirmed what marine scientists have long feared: the country’s vital reef ecosystems are steadily losing their structural complexity due to repeated bleaching events caused by extreme ocean temperatures.

The research, conducted between 2022 and early 2024, represents the most complete assessment of Thai coral reefs to date, surveying both fringing reefs and offshore coral formations across eight provinces along the Gulf of Thailand and Andaman Sea coasts. Thailand’s waters are home to more than 300 species of reef-building corals, but these diverse ecosystems have been repeatedly hammered by marine heat waves that trigger mass coral bleaching events.

The timing of this study proves particularly significant, as researchers completed their surveys just before the fourth global coral bleaching event began affecting Thailand’s reefs in 2024—damage that has yet to be fully quantified. According to Rahul Mehrotra, research director at the Aow Thai Marine Ecology Center and co-author of the study, the loss of structural complexity represents more than just coral death; it signals fundamental shifts in the species composition of entire reef communities, with cascading effects throughout marine ecosystems.

Unlike previous studies that focused on specific locations, this coast-to-coast assessment provides researchers, reef managers, and policymakers with a crucial baseline for measuring future changes. “Having this map of what corals are represented across the region gives us a starting point for conservation,” Mehrotra explained, emphasizing the need for more sophisticated monitoring approaches to protect these critical marine habitats.