More than 40% of coral species face extinction, according to new research

Following a global assessment, the IUCN Red List of Threatened Species has revealed that 44% of reef-building coral species globally are at risk of extinction. The announcement was made at the ongoing COP29 UN climate conference.

Dr. Michael Sweet, Professor of Molecular Ecology and Head of the Aquatic Research Facility at the University of Derby, is among a pool of experts who contributed to the global coral assessment, which has revealed the severe impacts of our rapidly changing climate.

The IUCN Red List has now reassessed the conservation status of 892 warm-water reef-building coral species, and analysis shows that 44% are threatened.

The threats to reef-building corals were last assessed for the IUCN Red List in 2008, and at that time one-third were found to be threatened.

During the assessment, coral species around the world were evaluated, with Dr. Sweet specializing in those found in the Caribbean, which is home to 10% of the world’s coral reef.

Staghorn coral (Acropora cervicornis) and Elkhorn coral (Acropora palmata) are two examples of Critically Endangered species in the Caribbean that have experienced significant declines due to increased warming, water pollution, hurricanes and the severe impacts of coral diseases.

Responding to the findings, Dr. Sweet said, “It was an amazing experience to be involved in such a large research project and to be part of an international team. However, the results that show so many corals are endangered are very alarming.

“Corals are vital ecosystems, they harbor upwards of 30% of all marine life, support around 1 billion people, and offer trillions of dollars of ecosystem services from fish to coastal protection. Corals bring so many benefits and our world relies on them, so it is vital we act now to protect them.”

The main solution to save corals from extinction is cutting greenhouse gas emissions, accompanied by actions to address other threats, to strengthen species’ resilience. The assessors also recommend more research into if and how corals can adapt to warmer waters, with evidence of limited adaptation so far.

Dr. Sweet added, “If we act now and take bold steps, we may just stand a chance of securing a future for humanity.”

Built over tens of thousands of years, coral reefs are the most biodiverse of marine ecosystems. Climate change causes rising water temperatures and more intense solar radiation, which lead to coral bleaching and disease, often resulting in mass coral mortality.

Beth Polidoro, IUCN Species Survival Commission Coral Red List Authority Coordinator, said, “We need to drastically cut greenhouse gas emissions alongside action to address local threats if we want to give coral reefs a chance to survive. By taking action now, we can slow the pace of ocean warming and broaden the window of opportunity for corals to potentially adapt and survive in the long term.”