No fewer than 44% of reef-building coral species are at risk of global extinction, according to the IUCN Red List of Threatened Species, which has announced the results of its global assessment at the COP29 UN climate conference in Azerbaijan.
The International Union for Conservation of Nature & Natural Resources has assessed the conservation status of 892 warmwater reef-building coral species for its Red List, which is currently marking its 60th anniversary. The last such assessment was carried out 16 years ago, when around 33% of corals were considered under threat.
“As world leaders gather at the UN climate conference in Baku, this global coral assessment vividly illustrates the severe impacts of our rapidly changing climate on life on Earth and drives home the severity of the consequences,” said IUCN director-general Dr Grethel Aguilar.
“Healthy ecosystems like coral reefs are essential for human livelihoods – providing food, stabilising coastlines and storing carbon. The protection of our biodiversity is not only vital for our well-being but crucial for our survival.
“Climate change remains the leading threat to reef-building corals and is devastating the natural systems we depend on. We must take bold, decisive action to cut greenhouse gas emissions if we are to secure a sustainable future for humanity.”
The findings were based on the most recent status update from the Global Coral Reef Monitoring Network (GCRMN) alongside current and future threats such as the projected increase in warming and major bleaching events, using Intergovernmental Panel on Climate Change (IPCC) data.
In addition to climate change and related severe bleaching events, other threats to coral health include pollution, agricultural run-off, disease and unsustainable fishing.
Staghorn and elkhorn
The IUCN offered as examples staghorn (Acropora cervicornis) and elkhorn coral (A palmata), Critically Endangered species in the Caribbean that had experienced significant declines because of increased warming, water pollution, hurricanes and the severe impacts of coral diseases.
The main solutions for saving corals from extinction are cutting greenhouse-gas emissions and actions to strengthen species’ resilience. The assessors also recommend more research into whether and how corals can adapt to warmer waters, with evidence of adaptation limited so far.
“We’ve known for decades that coral reefs are on the frontline of the global climate and biodiversity crises, and this new result only reconfirms this,” said Dr David Obura, co-chair of the IUCN SSC Coral Specialist Group.
“Without relevant decisions from those with the power to change this trajectory, we will see the further loss of reefs and progressive disappearance of coral species at larger and larger scales.”
Coldwater corals
The majority of corals are found across the Indo-Pacific but the global assessment of reef-building corals also includes 85 Atlantic species highlighted recently in a PLOS One journal article, these being particularly highly threatened by severe annual bleaching events, pollution and disease.
Red List assessments of coldwater corals are ongoing, with only 22 species of a total of 4,000+ having been assessed so far. The main threats to these species include bottom trawling, deep-sea mining, oil and gas drilling and deep-sea cable-laying, with white coral (Desmophyllum pertusum) one example of a species assessed as Vulnerable.
“The latest global assessment brings troubling news for corals, with more than 340 species now being considered at risk of extinction,” said MSC Foundation chief science advisor Prof David Smith.
“An ocean without functioning coral reefs would be a bleak reality, highlighting the urgent need to find solutions to the climate crisis while simultaneously addressing today’s coral crisis.”
Also on Divernet: SCIENTISTS DISCOVER HEAT-TOLERANT CORALS HIDDEN IN PLAIN SIGHT, CORAL CRASH: CAN OUR REEFS BE SAVED?, CORAL FARMERS RESHAPING THE FUTURE, BIG HEAT-RESISTANCE BOOST FROM SECORE’S SUPER-CORALS
