As Mauritius reopens its international borders on October 1, much hope is placed on new tourist arrivals to relieve the local economy after 19 months of constraints due to the pandemic. The tourist industries of Small Island Developing States have been successful due to the attractiveness of their lagoons and beaches, and they owe much of this renown to an oftentimes underestimated natural resource: coral reefs. As global citizens celebrate World Tourism Day on 27 September 2021, it is important to highlight the importance of these underwater ecosystems, which are the hidden foundation of the tourism industry, and provide enormous value to island economies.
Coral reefs are the rainforests of the oceans. They are net sinks for carbon and also contribute to fix nitrogen. Home to over 4,000 species of fish alone, they are also a source of income, food, and medicine for humanity. The Republics of Mauritius and Seychelles host more than 2,653 km2 of diverse coral reefs which act as natural barriers for the coastal zones. Buffering the shorelines against waves, storms, and floods, coral reefs protect beaches and create ideal conditions for many sea-based recreational activities which are vital for the tourism industry of Small Island Developing States.
In Mauritius and Seychelles, where tourism accounted for around 12% of GDP and above 39% of GDP respectively in 2019, coral reefs are real economic assets. Estimates indicate that coral reefs account for USD 2.7 trillion per year in ecosystem service value. Annual benefits have been estimated at USD 3,500 per square kilometer derived from fisheries, tourism, and coastal protection. However, this figure is likely to be an underestimate, as coral reefs also protect the real-estate and livelihoods of around one billion people.
Main causes of coral reefs destruction
During the three last decades, coral reefs have become the most threatened ecosystems on the planet. Globally, coral reefs have already lost 50% of their live hard coral cover between 1957 to 2007, and the need to protect them and preserve their services is greater than ever.
Climate change has emerged as one of the greatest threats to coral reefs. Even under modest scenarios of global warming (<1.5°C), between 70 to 90% of reef-building corals are predicted to die. In Mauritius, during the most recent coral bleaching event in 2016, sea-water temperatures rose above the average of 29oC, and 40 to 50% of the total live coral cover was impacted. The Seychelles, which has a total coral cover of around 1,690 km2, was not spared either as over 60% of sites experienced high or extreme bleaching in 2016, with a mortality rate of around 30%.
Human activities on land and at sea can also be major sources of stress for coral reefs. Overfishing and unsustainable fishing methods have disrupted the delicate ecological balance of coral reefs and caused direct harm to the integrity of their ecosystems. The tourism industry, which has brought increased volumes of waste and more intensive sea activities in the lagoons, has also played a role in the decline of coral reefs.
The spread of tourist infrastructures along shorelines has also occasionally led to unsustainable coastal development. In some regions of Mauritius, the removal of mangroves or seagrass has deprived the lagoons of their natural filters altering the composition of seawater to the detriment of the coral reefs. Such changes in the water composition of lagoons can also come from inland human activities. Seawater quality can also be degraded by sediments, nutrients and pesticides - used in agriculture and other human activities - that are carried into the sea by rivers and directly impact the corals.
As living organisms, corals can also be affected by bacteria, fungi, and viruses, and there are also natural predators of corals. The Crown of Thorns Starfish (COT), a voracious coral predator, has caused much harm to corals around Mauritius and Seychelles. Overfishing of COTs predators and pollution are factors that can contribute to outbreaks of these animals.
The compounding effect of these stresses is not only a reduction of reef health but also a reduction in the resilience of reef communities to naturally recover. As corals disappear, so do fish and many other reef-dependent species. This directly impacts the fisheries industry and the livelihoods and food security of island communities. The decline of coral reefs also reduces the natural protection of lagoons against waves and storm surges, and thus affects the tourist industry and other infrastructures found along the coast. It is therefore essential that major local reef threats are mitigated if we are to give coral reefs a fighting chance of survival in the face of a changing global climate.
Coral Restoration through Innovation
A global coordinated effort is required to develop targets and pathways for coral reef ecosystem recovery and adaptation while appropriate governance structure and policy framework are required to address needs at the local level.
The UNDP, with the support of the Adaptation Fund, has been at the forefront of increasing the resilience of coral reefs by improving institutional capacity and coral restoration efforts at national and regional levels.
Since 2020, with a grant of USD 10 M from the Adaptation Fund, the UNDP has been implementing the ‘Restoring Marine Ecosystem Services by Restoring Coral Reefs to Meet a Changing Climate Future’ project in the Republics of Mauritius and Seychelles.
The overall objective of this six-year regional project is to reduce the impact of climate change on local communities and coral reef-dependent economic sectors in the Republics of Mauritius and Seychelles, by implementing coral reef restoration with thermal tolerant corals as an adaptation to climate change. Under the project, the target is to restore approximately 2.5 hectares of coral reefs in Mauritius, 0.7 hectare in Rodrigues, and 2.5 hectares in Seychelles.
At the regional level, a solid knowledge base on the best practices regarding coral reef restoration, with particular emphasis on the SIDS, will be developed. Genetic connectivity studies between selected corals from Mauritius, Rodrigues and Seychelles will also be undertaken.
In line with the achievement of SDGs 3, 13, and 14, the project will ultimately contribute to (i) the reduction of risks from high-intensity storms, (ii) the protection of the tourism industries of both countries, and (iii) the enhancement of the value and sustainability of their coral reef fisheries.