A new study has found that coral disease has increased threefold in the last 25 years, and that three-quarters of coral reefs will likely be diseased by next century.
The study, published in Global Change Biology, analyzed data from more than 200 coral reef locations across the world from 1995 to 2020. The researchers found that coral disease prevalence increased from 2% to 6% over this period, and that climate change and human activities are the main drivers of this trend.
Coral diseases are caused by various pathogens, such as bacteria, fungi, and viruses, that infect and damage coral tissues. Some of the most common diseases are white syndrome, black band disease, and coral bleaching. Coral diseases can reduce coral growth, reproduction, and survival, and affect the ecosystem services that coral reefs provide, such as fisheries, tourism, and coastal protection.
The study also projected future scenarios of coral disease under different levels of greenhouse gas emissions and management interventions. The researchers found that under a high-emission scenario with no management actions, coral disease prevalence could reach 75% by 2100. However, under a low-emission scenario with effective management actions, such as reducing local stressors and restoring coral populations, coral disease prevalence could be reduced to 15% by 2100.
The study highlights the urgent need for global and local actions to mitigate climate change and protect coral reefs from disease outbreaks. The researchers suggest that monitoring coral disease, identifying disease-resistant corals, and enhancing coral resilience are some of the possible strategies to prevent further coral decline.