Most coral reefs in the Indo-Pacific region lack the capacity to grow fast enough to survive projected sea-level rise, scientists said.
This vulnerability threatens the biodiversity of the ocean and the coastal protections these reefs provide. If reefs cannot keep pace with rising waters, they risk submergence—a process often described as drowning—which limits the sunlight available for coral survival.
Scientists from Nanyang Technological University (NTU) in Singapore conducted the research published this month. The study indicates that 76% [1] of Indo-Pacific coral reef sites are unable to match the speed of projected sea-level rise.
The risk is most acute under scenarios involving high greenhouse-gas emissions. In these conditions, the rate at which the ocean rises exceeds the vertical growth capacity of the coral structures.
Coral reefs function as natural barriers that protect coastlines from erosion and storm surges. When these structures fail to maintain their position relative to the surface, the ecosystems can collapse, affecting the thousands of marine species that rely on them for shelter and food.
The NTU research team focused specifically on the Indo-Pacific region, which contains some of the most diverse marine environments on Earth. The findings suggest that the acceleration of sea-level rise is outstripping the biological adaptation speed of these reefs.
While some reefs may possess the resilience to adapt, the majority of the sites analyzed do not show the necessary growth potential to survive the high-emissions trajectory. The researchers said that the inability to keep pace with the water level leads to a loss of critical habitat.
“76% of Indo-Pacific coral reef sites lack the capacity to keep pace with projected sea-level rise”
The potential loss of three-quarters of Indo-Pacific reefs would trigger a systemic collapse of marine biodiversity and leave coastal human populations more vulnerable to extreme weather. Because these reefs act as the first line of defense against the ocean, their 'drowning' would increase the frequency and severity of coastal flooding in some of the world's most densely populated maritime regions.
