Risk assessment of coral reef vulnerability to climate change and stressors in tropical islands: The case of Mauritius

Coral reefs play a critical role in the socio-economic development of oceanic islands, besides offering coastal protection against the destructive forces of the sea under storm conditions. A Multi-Criteria Decision Making-based geospatial model is used which combine highly influential climatic, ecological, and anthropogenic reef degradation factors in view of revealing regions of high coral reef vulnerabilities to inform ecosystems conservation and management. Further investigation of the coastal seawater temperature trend revealed a rise in sea surface temperature approximating 0.66 & DEG;C over the 2003-2020 period as compared to the 1985-2003 interval, with a decadal temperature rise of 0.16 & DEG;C reported to be higher than the global average. The bleaching threshold in the region is frequently exceeded during the postmillennial period, further reducing coral fitness. Finally, management strategies are proposed here, which include the adequate design of Marine Protected Area networks, and the implementation of policy strategies for fertilizer use, sustainable coastal development projects, and control of reef predator population. The insights in this paper are expected to be applicable in the reef management of other oceanic islands.

Automated summary

Coral reefs are crucial for the socio-economic development and coastal protection of oceanic islands. This study uses a geospatial model based on Multi-Criteria Decision Making to identify vulnerable regions for coral reef conservation and management, considering climatic, ecological, and anthropogenic factors. The investigation also reveals a significant increase in sea surface temperature, higher than the global average, resulting in frequent bleaching events and reducing coral fitness. Management strategies proposed include Marine Protected Area networks, policy strategies for fertilizer use and coastal development, and control of reef predator population. The insights from this study are valuable for reef management in other oceanic islands.