Coral reefs in the South Mascarene Islands are at risk

Problems

• The South Mascarene Islands are home to some of the most unique and diverse coral reefs in the world, with over 300 species of corals and 1,200 species of fish. These reefs support a variety of economic sectors, such as tourism, fisheries, and coastal protection, as well as cultural and spiritual values. 
  
  However, these reefs are also at high risk of collapse within the next 50 years, according to a study by IUCN and CORDIO East Africa. The study assessed the coral reefs in the Western Indian Ocean using the IUCN Red List of Ecosystems criteria. This framework evaluates the risk of ecosystem collapse based on changes in key processes and functions. The study found that all coral reefs in the region are at high risk of collapse, but reefs in island nations, such as the South Mascarene Islands, are under particularly high threat. The study classified the reefs in the South Mascarene Islands as ‘Critically Endangered’, meaning that they have experienced severe and widespread degradation and are likely to collapse shortly.
  
  The main threat to the coral reefs in the South Mascarene Islands is ocean warming due to climate change. Ocean warming causes coral bleaching, a phenomenon where corals lose their symbiotic algae and turn white. Bleached corals are more susceptible to diseases, predation, and mortality. The study found that the South Mascarene Islands have experienced frequent and severe coral bleaching events in the past two decades, resulting in significant coral mortality and reduced coral cover. For example, in 2016, a major bleaching event killed up to 90% of corals in some sites in Mauritius and Réunion.
  
  Other threats to the coral reefs in the South Mascarene Islands include overfishing, coastal development, pollution, invasive species, and natural disasters. Overfishing reduces the abundance and diversity of fish and other reef organisms, which affects the ecological balance and resilience of the reefs. 
  
  Coastal development and pollution increase the sedimentation and nutrient loading of the water, which reduces the light and oxygen available for corals. Invasive species, such as the crown-of-thorns starfish, can cause massive damage to corals by feeding on them. Natural disasters, such as cyclones, can also cause physical damage to the reefs and alter their structure and function.
  
  The study also identified some potential solutions and actions to conserve and restore the coral reefs in the South Mascarene Islands. These include reducing greenhouse gas emissions to limit global warming and ocean acidification, improving local management of fisheries and marine protected areas, enhancing coral reef monitoring and research, promoting coral reef restoration and adaptation, and raising awareness and engagement of stakeholders and communities. The study emphasized the need for regional and international cooperation and coordination to address the common challenges and opportunities for coral reef conservation in the Western Indian Ocean.
  
  In conclusion, coral reefs in the South Mascarene Islands are at high risk of collapse due to multiple threats, especially ocean warming. These reefs are of high ecological, economic, and cultural value, and their loss would have devastating consequences for the islands and their people. Therefore, urgent and concerted action is needed to protect and restore these reefs and to ensure their sustainability and resilience for the future.