Critical Coral Reef Crisis: Over 80% of Corals Bleached with a 50% Mortality Rate

Title: Critical Coral Reef Crisis: Over 80% of Corals Bleached with a 50% Mortality Rate

Content: In 2025, Mauritius' coral reefs faced an unprecedented crisis with over 80% of corals experiencing severe bleaching and around 50% mortality, especially in shallow waters, leaving little hope for recovery due to the increased frequency of climatic events.

The Minister of Agro-Industry, Fisheries and the Blue Economy, Arvin Boolell, highlights the alarming state of Mauritius' coral reefs. Recent observations indicate that "in 2025, over 80% of coral bleaching was recorded at survey sites with approximately 50% coral mortality, particularly in shallow waters, marking a severe event." The situation is thus extremely critical regarding the degradation of marine ecosystems, exacerbated by climate change, and calls for urgent action to preserve these vital habitats.

Critical Situation

Coral reefs, described as "some of the most productive and biologically diverse ecosystems in the world," are facing imminent collapse mainly due to the impacts of climate change, which is "the primary cause of coral bleaching." Minister Boolell notes in a written response submitted to the National Assembly that "coral reefs in the western Indian Ocean, like elsewhere in the world, have suffered from a range of negative human-induced impacts, but climate change-related bleaching is the main cause of serious degradation in Mauritius and other islands."

The history of bleaching events illustrates the escalation in frequency and intensity. After a major episode in 1998, Mauritius' reefs have suffered successive bleaching events in 2001, 2002, 2005, 2009, 2012, 2016, 2018, 2022, 2024, and 2025. Their intensity was classified as "severe" in 1998 and 2025, "mild" in 2001, 2002, 2005, 2009, 2012 and 2022, and "moderate" in 2002, 2016 and 2018 (Coral Reef Status Report for the Western Indian Ocean, 2017). The minister explains that "the extent and frequency of bleaching events due to climate change over the years have increased." He adds that "corals need ten to fifteen years to fully recover after a major bleaching event, but warming events now occur every two to three years, leaving little to no recovery time."

This critical situation affects not only the marine environment but also dependent economic sectors such as fishing and tourism. Although "there have been no specific studies or assessments on the impact of this situation on the national economy regarding the fishing sector," the minister announces the upcoming establishment of a technical committee involving several ministries to explore ways to mitigate the economic impacts of coral bleaching on these two sectors. Moreover, "my ministry will seek assistance from the United Nations Development Programme (UNDP) and the EU delegation in Mauritius in this regard."

National Actions

In response to this urgency, the Mauritian government has launched a series of national actions to enhance the resilience of marine and coral ecosystems. Since 1996, the ministry has established long-term monitoring stations around Mauritius, including in the Blue Bay Marine Park and Balaclava Marine Park, which are monitored annually. These stations provide scientific data for policy actions, reported in annual reports.

For protection, Mauritius has declared eighteen marine protected areas, consisting of fishing reserves, marine parks, and marine reserves. Eight are located in Mauritius and ten in Rodrigues, with plans to declare new ones to protect and conserve marine biodiversity. Currently, approximately 13,953 hectares of the marine environment are legally protected, including 7,190 hectares in Mauritius and 6,763 hectares in Rodrigues.

In terms of restoration, the ministry initiated a coral cultivation project through asexual reproduction (micro-fragmentation) for the first time in Albion in 2008 on a pilot basis. Having achieved very promising results, similar projects have been replicated on a large scale at several sites around Mauritius, including the Blue Bay Marine Park, Balaclava Marine Park, Trou-aux-Biches, Pointe-aux-Sables, and Albion. A similar project was also conducted for the first time at Graviers, Rodrigues in 2009.

Community initiatives have been launched, such as the community-based coral cultivation project, funded by the government from 2017 to 2020, which trained 102 community members, including fishermen, women, and boat operators, in coral cultivation techniques. This project was implemented in Quatre-Sœurs, Grand-Gaube, La Gaulette, and Baie-du-Cap.

Coral Cultivation

Currently, the ministry is implementing a coral cultivation assistance program in Belle-Mare, Grand-Gaube, Le Morne, and Bel-Ombre, where a total of 341 fishermen and aspiring fishermen, including women, are being trained in two coral cultivation techniques: the basal table technique developed by the Albion Fisheries Research Center and the multi-layer rope technique established by the Mauritius Oceanographic Institute.

The Albion Fisheries Research Center (AFRC), under the Ministry of Agro-Industry, Fisheries and the Blue Economy, has also launched a coral cultivation project through sexual reproduction, in collaboration with technical experts from the Japan International Cooperation Agency at Blue Bay, Île-aux-Aigrettes, and GRSE.

Under the coral restoration project funded by the Adaptation Fund/UNDP, the government has provided funding amounting to Rs 6 million and Rs 59 million for the construction of two land-based coral nurseries, one at the Albion Fisheries Research Center for sexual reproduction and the other at the Mauritius Oceanographic Institute aimed at restoring corals through micro-fragmentation techniques and also with heat-resistant corals. Both land-based coral nurseries will be operational in 2026.

The staff of the Albion Fisheries Research Center and the Mauritius Oceanographic Institute have also been trained in coral genetics under the coral restoration project funded by the Adaptation Fund/UNDP. The government has already established a list of heat-resistant coral species for the Republic of Mauritius.

To protect the reefs, the Fisheries Act of 2023 has been strengthened to better protect Mauritius' coral reefs. Destructive fishing methods such as the use of gill nets, toxic substances, and explosives, spear guns, and underwater firearms are prohibited under the Fisheries Act of 2023. Additionally, the removal, destruction, and sale of shellfish and corals are prohibited by the Fisheries Act of 2023 in Mauritius.

Due to habitat destruction caused by coral mortality and the decline of fish in lagoons, the ministry has installed fish aggregation devices (FADs) at sea to relocate fishing activities from the lagoon to offshore. Fishermen are trained in fishing with FADs at the Fisheries Training and Extension Center (FITEC) in Pointe-aux-Sables, before being issued fishing cards. Currently, the ministry only issues fishing cards for offshore fishing. A total of 694 fishermen attended the general fisher course held at FITEC in 2024 before being assigned a fishing card.

The net buyback program was introduced in 1996, encouraging fishermen to relinquish their nets in exchange for compensation. Fishing with gill nets and drift nets has also been banned. Globally, Mauritius is a co-champion with Australia and Belize under the Commonwealth Blue Charter Action Group for the protection, conservation, and restoration of coral reefs. Mauritius supports the Blue Charter as a means of contributing to the ecologically sustainable management of our oceans.