The Mauritius tourism model, documented in Article 8 of this edition, is built on three natural assets: the lagoon, the reef, and the beach. The lagoon is defined by the reef that creates it. The beach is maintained by the sediment and coastal protection that the reef provides. The reef is alive. Alive reefs are temperature-sensitive. Sea surface temperatures around Mauritius have been rising since the instrumental record began, and the scientific documentation of what that rise is doing to the reef that defines the tourism product is precise, current, and publicly available from the institutions responsible for monitoring it. This article presents that documentation in the same analytical register as every other article in this edition: primary sources, named institutions, verified figures. The climate exposure of the Mauritian economic model is not a matter of future risk assessment. It is a present reality measurable in the percentage of bleached corals in Mauritian waters in March 2025.

On 15 April 2024, the United States National Oceanic and Atmospheric Administration, in partnership with the International Coral Reef Initiative, confirmed that the world was in the midst of its fourth global coral bleaching event, the most extensive on record. NOAA's official press release confirmed widespread bleaching across the Indian Ocean basin including, specifically named, Mauritius, Tanzania, Kenya, the Seychelles, Tromelin, Mayotte, and off the western coast of Indonesia. From 1 January 2023 to 30 September 2025, bleaching-level heat stress had impacted approximately 84.4 per cent of the world's coral reef area and mass coral bleaching had been documented in at least 83 countries and territories, according to NOAA Coral Reef Watch's status update of September 2025.

Mauritius is home to approximately 250 species of coral, according to documentation cited in Mongabay's October 2025 investigation into Mauritius coral restoration. In March 2025, ocean heat waves bleached 80 per cent of corals in Mauritian waters, according to Pierre Edgard Daniel Marie, Director of the Mauritius Oceanography Institute, the primary national scientific body responsible for marine monitoring. This figure was stated directly by the MOI Director to Mongabay in October 2025. It is an institutional statement from the director of the competent Mauritian scientific authority, not an estimate or a model projection. Eighty per cent of the coral in Mauritian waters was bleached in a single season.

The scientific context for this event is documented in research published in Sea Technology magazine in October 2025, drawing on the peer-reviewed literature on Mauritius reef systems. Since 2003, sea surface temperatures around Mauritius have risen by 0.16 degrees Celsius per decade, a rate that has surpassed the bleaching threshold of 27.5 degrees Celsius and reduced the thermal margin available to coral before bleaching is triggered. Even small temperature anomalies of 1 degree Celsius or more cause mass bleaching events in Mauritian waters. The historical record of bleaching events in Mauritius, documented in the same scientific literature, shows events in 1998, 2006, 2016, and 2024. The frequency has increased from approximately one event per decade to approximately one every eight years. The trend is in the direction of more frequent, not less frequent, events.

Sea levels around Mauritius rose at an average rate of 3.8 millimetres per year between 1987 and 2014, according to peer-reviewed research cited in the Sea Technology October 2025 analysis of climate change impacts on Mauritian reefs. Over the 27-year measurement period, this represents a cumulative rise of approximately 10.3 centimetres. The IPCC Sixth Assessment Report, published in 2021 and 2022, projects that under intermediate emissions scenarios (SSP2-4.5), global mean sea level will rise by approximately 0.32 to 0.62 metres by 2100 relative to the 1995-2014 baseline. Small island developing states in the Indian Ocean are projected to experience sea level rises consistent with or exceeding the global mean, as the regional sea level response in the Indian Ocean has been above the global average in recent decades.

The coastal infrastructure of Mauritius, the resort complexes, the hotel room stock, the beach infrastructure, the marinas, and the coastal road network, was built at elevations calibrated to current sea levels, not to projected mid-century sea levels. The 85 per cent of Mauritius hotel rooms that are in the premium and luxury category, as documented by the AXYS Hospitality Industry Report 2026 cited in Article 8, are disproportionately located on the coastline precisely because proximity to the beach is the primary luxury tourism asset. This is the intersection of the economic model and the physical exposure: the highest-value segment of the tourism infrastructure is located in the zone most exposed to the sea level rise that the scientific record documents.

The relationship between reef health and tourism revenue is not theoretical. The Mauritius tourism product is sold on the basis of its marine environment: the snorkelling, the diving, the glass-bottom boat tours, the visual appeal of the turquoise lagoon defined by the living reef at its outer edge. Tourist operators, travel agents, and destination marketing agencies position Mauritius as a premium Indian Ocean destination on the strength of its natural environment. That natural environment is experiencing the documented degradation this article describes. Eighty per cent of corals bleached in a single season is not a minor aesthetic concern. It is the removal of the biological foundation of the product that premium tourists are paying, at EUR 121 per day on average according to the AXYS 2026 data, to experience.

Ocean acidification compounds the bleaching risk. Peer-reviewed research monitoring declining pH levels at sites including Bel Ombre, Bambous Virieux, and Trou aux Biches, documented in the Sea Technology analysis, indicates that the capacity of Mauritius reef systems to calcify and rebuild after bleaching events is being chemically reduced simultaneously with the thermal stress that triggers the events. The reef that bleaches under the 2024 event cannot recover as effectively under acidifying ocean chemistry as the reef that bleached in 1998 could under earlier chemical conditions. Each bleaching event is more damaging in its long-term consequences than the last, even when the intensity of the thermal stress is comparable, because the chemical environment in which recovery must occur has deteriorated.

The IPCC Sixth Assessment Report projects that while the total global frequency of tropical cyclones may remain stable or decline slightly under climate change scenarios, the proportion of cyclones reaching Category 4 and 5 intensity is projected to increase. The physical mechanism is straightforward: warmer sea surface temperatures provide more energy to developing cyclones, intensifying the strongest storms even if the overall count does not increase. For Mauritius, located in the South Indian Ocean cyclone basin, this projection means that the storms that do reach the island will be more intense on average than the historical record. The tourism infrastructure built to the engineering standards of the 1980s, 1990s, and 2000s was not designed for the cyclone intensity projections of the 2040s, 2050s, and 2060s.

The economic consequence is concentrated in the same coastal strip that faces the sea level rise risk and that holds the majority of the premium hotel stock. A Category 4 or 5 cyclone making direct landfall on the north or west coast of Mauritius, where the highest concentration of IRS and luxury resort infrastructure is located, would produce insurance claims, reconstruction costs, and revenue interruption losses whose scale has not been systematically assessed in any publicly available Mauritius government document. The climate exposure of the tourism model is physical, concentrated, and documented by the scientific institutions responsible for monitoring it. The absence of a comprehensive climate risk assessment for the tourism infrastructure in the published record of the Mauritian government is itself a structural observation.