Coral reefs are vital ecosystems that support a diverse range of marine life and provide significant benefits to coastal communities. However, they are increasingly threatened by climate change and pollution. According to a report by the Global Coral Reef Monitoring Network (GCRMN), though Coral reefs cover only 0.2% of the ocean floor, they offer significant benefits up to 25% of the marine ecosystem. Beyond marine life, Reuters estimate that coral reefs contribute to up to £2.2 trillion (about $2.7 trillion) in goods and services to the tourism sector for countries they can be found in. Mauritius, a small island nation in the Indian Ocean, is one such country. Surrounded by approximately 300km of coral reefs, it’s home to some of the most beautiful reefs in the world.
Despite their significant benefits, the report highlights that loss and damage to coral reefs around the world have grown significantly over the past decades. While some scientists state that more than a fifth of the world’s reefs have been damaged, others argue that the figure is actually more substantial and applies to over 50% of coral reefs dying in the last 30 years. Tunley’s Environmental Scientist and Mauritian native Dr Anusha Nawoor writes on how coral bleaching affects reefs in Mauritius, its effect on the local ecosystem and ongoing conservation efforts.
What is Coral Bleaching?
Coral bleaching occurs when corals become stressed due to changes in environmental conditions, such as elevated sea temperatures, ocean acidification and pollution. During this stress, corals expel the symbiotic algae (zooxanthellae) that provide them with food and colour, leading to a stark white appearance. If the stress persists, it can result in coral death, significantly impacting marine biodiversity and coastal protection.
How Does Climate Change Impact Coral Bleaching?
Global coral bleaching poses a significant threat to the livelihoods and safety of coastal communities while jeopardising the overall health of the ocean. Communities are increasingly concerned about the potential loss of tourism and income due to this phenomenon. The World Wildlife Fund (WWF) has urgently called on countries to take immediate action to alleviate stress on coral reefs by reducing greenhouse gas emissions, enhancing protections around affected reefs and minimising harmful runoff from land. The global coral bleaching event, announced in April 2024 by the U.S. National Oceanic and Atmospheric Administration (NOAA), is expected to have severe negative consequences for both coastal communities and ocean health. This event indicates that extensive areas of tropical reefs across the Atlantic, Pacific and Indian Oceans are experiencing extreme stress, which, if sufficiently severe or prolonged, can lead to coral mortality. This is the second global coral bleaching event in the past decade and the fourth overall, triggered by record-shattering ocean temperatures that began last year, as the ocean absorbs 90% of the excess heat generated by burning fossil fuels.
Being a small island state, Mauritius is already experiencing the adverse effects of climate change firsthand. According to a recent report published by the Ministry of Environment, Solid Waste Management and Climate Change, the average annual temperature has risen by around 1.39°C over the past 70 years, surpassing the global average. The country is likely to face prolonged periods of drought, with predictions of water shortages as early as 2030. Additionally, the average sea level around Mauritius is rising faster than global averages, leading to increased coastal erosion and a direct impact on tourism and the economy. Marine heatwaves pose a significant threat to coral reefs, which are crucial for marine life reproduction and artisanal fishing. The Mauritius Oceanography Institute (MOI) has launched several projects to monitor sea level rise, study erosion patterns and restore marine ecosystems. These initiatives include training local fishermen in coral nursery maintenance and assessing living marine resources in the Exclusive Economic Zone (EEZ) of Mauritius.
Current Status of Coral Bleaching in Mauritius
As of 2023, Mauritius has experienced several episodes of coral bleaching, particularly during periods of elevated sea temperatures. The summer months, typically from December to March, have seen the most significant impacts. Reports indicate that certain areas of the lagoon have experienced bleaching events, with varying degrees of severity across different reef sites. Recent studies conducted by marine biologists and environmental organisations have shown that while some reefs have demonstrated resilience and recovery, others remain severely affected. The government of Mauritius, alongside local NGOs, has been actively monitoring these reefs to assess the extent of bleaching and implement necessary conservation measures.
A cross-section of the ocean view in Mauritius
Conservation Efforts
In response to the ongoing challenges posed by coral bleaching, Mauritius has initiated several conservation programs aimed at protecting and restoring its coral reefs. These efforts include:
- Marine Protected Areas (MPAs): The establishment of MPAs has been a crucial step in safeguarding coral ecosystems from overfishing and pollution. These areas allow for the recovery of marine biodiversity and provide a refuge for stressed coral populations.
- Coral Restoration Projects: Various organisations are engaged in coral restoration initiatives, which involve cultivating coral nurseries and transplanting resilient coral species back onto degraded reefs. These projects aim to enhance the resilience of coral populations against future bleaching events.
- Public Awareness Campaigns: Educating local communities and tourists about the importance of coral reefs and the threats they face is essential. Awareness campaigns focus on promoting sustainable practices, such as responsible snorkelling and diving, to minimise human impact on these fragile ecosystems.
- Research and Monitoring: Ongoing research is critical to understanding the dynamics of coral bleaching and the effectiveness of conservation strategies. Collaborative efforts between government agencies, universities and international organisations are essential for gathering data and informing policy decisions.
The Bottom Line
The status of coral bleaching in Mauritius remains a pressing concern, with ongoing challenges posed by climate change and environmental stressors. However, through concerted conservation efforts and community engagement, there is hope for the resilience and recovery of these vital ecosystems. Continued monitoring and research will be essential in adapting strategies to protect Mauritius's coral reefs for future generations. As we move forward, it’s imperative that both local and global communities recognise the importance of coral reefs and take action to mitigate the factors contributing to their decline. Together, we can work towards a sustainable future for Mauritius's coral ecosystems.
References:
Mauritius Oceanography Institute. (2023). Coral Bleaching Monitoring Report. Retrieved from Mauritius Oceanography Institute
World Wildlife Fund. (2023). The Impact of Coral Bleaching on Marine Biodiversity. Retrieved from WWF
Mauritian Ministry of Environment. (2023). Conservation Strategies for Coral Reefs. Retrieved from Ministry of Environment