As the world grapples with rising temperatures and accelerating ocean heat waves, a new study has revealed that certain coral reefs in the Western Indian Ocean may be more resilient to climate change than previously thought.
The Western Indian Ocean (WIO) is a region encompassing the islands of Madagascar, Mauritius, Seychelles, Comoros, and Réunion, as well as the coastlines of Kenya, Tanzania, Mozambique, South Africa, and Somalia.
Published in the journal Ecosphere under the title Predicting Coral Reef Diversity in the Western Indian Ocean Using Fine-Scale Modeling, the research by scientists from Wildlife Conservation Society (WCS), combines AI models with data from 1,000 field studies to identify reefs that could better withstand climate change, offering new hope for conservation efforts in the region.
Dr Tim McClanahan, Director of Science for WCS’s Global Marine Program, says unlike previous models, which were often simplistic and relied on just a few temperature variables, their new system harnesses the full potential of global environmental mapping and machine learning. This approach opens up new opportunities to identify resilient reefs that are in need of protection.
The new model, which takes into account a wide range of environmental variables on a smaller scale, provides a more detailed and diverse outlook for coral reefs.
This challenges the more severe predictions of previous models, including the 2023 Intergovernmental Panel on Climate Change (IPCC) report. Under a 1.5°C warming scenario, the model predicts that 70 percent of reefs will experience only mode.
However, they say, if emissions were to continue unmitigated, coral cover could decline by 40 percent by mid-century.
In WCS’s new model, about 5 percent of coral reefs have been identified to potentially benefit from changing conditions, suggesting potential refugia where corals could continue to thrive despite warming.
“Understanding the complex interactions between climate change, human activities, and local conditions is crucial for informing targeted local conservation measures to protect and sustain coral reefs in a changing world,” added Maxwell Azali, a co-author on the study and Fisheries Analyst at Global Fishing Watch.
The study combines these predictions with coral cover data from previous research, allowing scientists to map coral resilience across the Western Indian Ocean.
“Our research indicates that about 30 percent of reefs worldwide could withstand a 1.5°C temperature increase,” said Dr. McClanahan. “However, with that threshold already surpassed, only 15 percent of reefs are expected to remain resilient without urgent carbon mitigation. This suggests that more extreme scenarios from previous models are likely unless immediate action is taken to reduce greenhouse gas emissions.”
Known for its rich diversity of marine and coastal ecosystems, the WIO features coral reefs, mangroves, seagrass beds, beaches, and lagoons.
Over 60 million people call the WIO home, relying on its coastal and marine resources for food, shipping, and tourism. While the region’s economies depend on healthy ocean and coastal ecosystems, these are increasingly threatened by activities that endanger both marine life and coastal communities.
Researchers hope their modeling methods will be used globally to map biodiversity with greater accuracy, enhancing conservation efforts for ecosystems at high risk from climate change.
