Remote Indian Ocean Reef Bounces Back After Bleaching
Coral reefs in remote or protected areas can recover quickly after mass coral bleaching events, new research shows.
University of Exeter researchers are investigating "reef carbonate budgets" - the net production or erosion of reef structure over time. To study the impact of climate change, they examined 12 reefs in the remote Chagos Islands in the Indian Ocean before and after the global coral bleaching event in 2015/16.
In 2018, the thriving reefs were "shrinking", with coral cover and carbonate production down by more than 70% and erosion processes exceeding new growth. When the researchers returned in 2021, all reefs were recovering, although at different rates from place to place. Where it had recovered quickly, the main reef structures had stayed intact and had started to positively grow again.
Bleaching is caused by warmer water temperatures, which can trigger corals to expel their symbiotic algae and turn white. Corals can survive this, but an extreme heat wave causes large scale mortality. The speed of recovery indicates the reef's health and resilience.
Picture credits: Dr Ines Lange
Pictures showing reefs recovering after bleaching event.