Study suggests three-quarters of Indo-Pacific coral reefs could drown as sea levels rise

A recent study led by researchers at Nanyang Technological University, Singapore, has found that three-quarters of coral reefs in the Indo-Pacific region may struggle to keep pace with accelerating sea-level rise. The research, published in Nature Communications, reveals that 76% of surveyed reef sites lack the capacity to grow fast enough to maintain their position as water levels rise.

If current greenhouse gas emissions continue unchecked, there is a high probability (over 90%) that these reefs will suffer "reef drowning" within 35 years, according to the study's lead author Dr. Riovie Ramos. This threshold is expected to be surpassed within the next three decades unless significant reductions in global greenhouse gas emissions are implemented.

Coral reefs, formed over thousands of years, provide vital coastal protection and marine habitats. However, they can only grow so quickly, and when sea levels rise faster than they can build upward, the reefs become progressively submerged. While individual corals can grow rapidly, entire reefs do not expand at the same rate due to various factors such as coral communities and local physical conditions.

The study analyzed 288 ancient reef records from 92 sites across the Indo-Pacific, revealing that long-term reef growth is influenced by a combination of sea-level change, coral communities, and local physical factors. Smaller, more resilient coral species may further hinder reefs' abilities to maintain structures against rapid submergence.

The loss of complex reef structures could lead to increased coastal erosion, flooding, and reduced habitats for marine life, affecting fisheries, tourism, and local communities. While local conservation efforts may help maintain healthy coral communities, they cannot compensate for sea-level rise exceeding reefs' growth rates.