The figures, scientific analyses and climatic events of recent decades clearly demonstrate the great fragility of Mauritius in ecological terms. As a small tropical oceanic island, it is inherently vulnerable to climate change. and made part of the world’s 36 biodiversity hotspots, characterized by their endemic richness in a threatening environment. Awareness is growing, but action is still too slow and minimalist , face à the urgency of the three crises that affect us all: global warming, the 6e extinction of living species (the first due to human activities) and finally, pollution and waste. The indicators are all in the red, so cheer up! Hope is never lost. Dominique Bellier
Will the sudden yet predictable floods that trapped the inhabitants of Port-Louis and those who went there to work on January 15 be enough to trigger the necessary questioning and changes? The past teaches us that it won’t, since the 4 deaths of March 26, 2008 didn’t prevent the 11 deaths of March 30, 2013, which didn’t prevent those of the beginning of this year… Let’s not forget the damage caused in the south-east by the floods of April 2021, nor the chronic flood victims who have the misfortune of living in the wrong place and being unable to settle elsewhere.
Global warming is a tangible fact of life in Mauritius, and is having an ever greater impact on the lives of its inhabitants. Entire economic sectors are already suffering, notably fishing and agriculture, and others will soon be affected, with tourism at the forefront… If environmental amnesia were to cease and courageous decision-makers were to take the measure of what scientists have been explaining for decades, we could stop driving straight into the wall, like those motorists who were sent to work on January 15.
Since 2021, a UN report has ranked Mauritius as the 51st country most exposed to natural hazards. As a small, vulnerable island state, it will lack the means to manage the consequences of this situation alone, until a regional organization pools them, following the example of what is already being done in our territorial waters, for oil spills and illegal fishing under the impetus of the IOC. Another UN report from 2017 tells us that we will be under water stress from next year. Drought periods are lengthening and days of intense rainfall are increasing. Mauritius is forecast to become a water-poor country from 2030, and without new types of storage, this vital resource would decrease by 13% by 2050.
Overheating effects
The expression “above seasonal normals” is often used in our weather reports. We could add: above global averages, in terms of sea temperature and sea-level rise. In fact, temperatures have risen by 1.39°C between 1951 and 2020. The BRIO project, which analyzes meteorological data, predicts average increases of 3.14 to 3.64°C by 2100. Documents available online on the Ministry of the Environment website detail the effects of climate change on Mauritius. Water temperatures in the lagoon are rising faster than expected, cyclones are not more numerous, but they are forming faster and are more intense. The probability of intense cyclones in the south-west Indian Ocean is increasing by 18% per decade.
Flash floods and heavy rains are becoming a habit, leading to more landslides, of which there have already been many, and uprooted trees (200 in the days following Belal). Between 2011 and 2020, compared with 1991 and 2000, average sea level rose by 11.9 mm per year, and a further 49 cm is forecast by 2100. In 2018/2019, around 60% of our corals were subject to bleaching, according to official surveys.
Several beaches have retreated 20 meters, and some have virtually disappeared, such as La Preneuse, which is no longer the popular leisure spot it once was… It has even been estimated that the tourism sector will lose US$ 50 million in sales by 2050.
The Ministry of the Environment has set up a climate change department, and the government has set up various crisis management units such as the National Emergency Operations Command (NEOC). It has set up an authority for the construction of drains across the country, which is said to have identified more than 300 points of water accumulation, without however making public its masterplan, to be completed in 2022. The awareness is there, but we can’t anticipate floods, we don’t know how to evacuate Port-Louis in good conditions and we are regularly forced into crisis management.
Fortunately, the admirable Mauritian solidarity chain instantly rose up to extract motorists and pedestrians from the Port-Louis chaos, as in the days of Wakashio, as in every cyclone… between neighbors, with the support of the road services. Fortunately, neither Belal’s winds exceeded the 165 km/h and rainfall of 200 mm in 24 hours! We mourn two deaths, but what happens to the living after such a traumatic event? And how do people living in flood-prone areas survive?
Spotlight on reefs
Up until 2003, the sea water in the lagoon never exceeded 29°C, but its temperature began to rise in the 1980s, before dropping into the red in 2000 and rising steadily thereafter. The reefs have been systematically monitored since 1996. Coral bleaching was one of the first warnings that the authorities took into account, because the reefs represent the last bastion protecting our coasts, now that we have destroyed all the dunes and most of the wetlands, which have been drained in favor of “feet in the water” construction.
Our marine biodiversity is suffering the combined effects of global warming and human activities, with one of the ten highest population densities in the world, coastal urbanization, the growth of tourism and its activities at sea, not to mention the discharge of all kinds of land-based pollution. The base of the marine food chain, phytoplankton, has lost much of its density.
In a scientific study published last year on the vulnerability of our reefs, Jay Doorga and three of his colleagues recall that before 2005, this exceptional Mauritian crown was home to 159 species of hard corals, 127 macroalgae, 263 species of fish and over 3,500 molluscs! But a comparison between 2004 and 2019 shows that hard and soft corals have declined by 40% and 83% respectively on our shallow reefs. On a global scale, the extent of coral forests has decreased by 14% over 40 years.
This study maps the most vulnerable reef zones according to the aggressions suffered, and proposes viable solutions to enhance the effectiveness of marine protected areas which, by the way, represent only a tiny fraction of our territorial waters (less than 0.01%). Reducing the impact of the agricultural sector would be enhanced by new forms of fertilizers and composts, or buffer zones that capture nitrogen effluents, for which farmers would be compensated.
Champion of extinction
Although the islands of the south-west Indian Ocean were colonized late by humans, Mauritius and Rodrigues are now home to some of the most ecologically devastated environments in the world, even when compared to other tropical oceanic islands.
Being small,” explains Vincent Florens, Chair of Ecology at the University of Mauritius, “leads to more rapid degradation, as evidenced by the fact that Rodrigues has lost virtually all its native forest. The smaller an island, the smaller its populations of living species, which are therefore likely to disappear rapidly under anthropic pressure… Slash-and-burn farming and turtle exploitation in Rodrigues have had a deleterious impact. In Mauritius, the sugar boom between 1840 and 1870 led to the most massive destruction of natural areas. The little native forest that remains is located where there is no arable land, in Pétrin, or Plaine Champagne, in hard-to-access areas such as mountains and craters, gorges or rocky areas. Rodrigues has less than 1% of its territory covered by native vegetation; Mauritius has 4.4%, just under half of which is dominated by native plants in the canopy. And here again, native forests that do not benefit from conservation management – eliminating invasive species such as ravenale or Chinese guava – are dominated in their undergrowth by exotics… ”
Rodrigues has recreated its plant heritage from scratch, as in the François Leguat reserve. On this island, which is older than Mauritius, there is less demographic pressure.
10 years ago, it was estimated that Mauritius had lost 8.8% of its flowering plants; Rodrigues 11.3%. Today, it is estimated that 80% of Mauritian native species are in danger of extinction. 70% for the Seychelles. According to the State of the world’s trees, published in 2021 by Botanical garden conservation international (BGCI), Mauritius is number 2 worldwide in terms of the percentage of native trees in danger of extinction, with Madagascar having the sad privilege of first place. The disappearance of endemic forests naturally affects the lives of animals, who can no longer find food and shelter there. All endemic reptiles in Rodrigues have disappeared, and 31.3% in Mauritius, which has also lost 44.4% of its endemic snails, compared with 31.3% in Rodrigues. Finally, Mauritius lost 63.2% of its endemic land birds, and Rodrigues 84.6%.
Migratory birds stay away
Even migratory birds are visiting in smaller numbers. The largest migratory bird reserve in the Mascarenes, the Terre Rouge bird sanctuary, is attracting fewer and fewer of them, according to a study published in 2020 in the scientific newsletter Phaeton. A comparison of bird counts over two periods, from 2010 to 2019 and from 1989 to 1993, shows that populations of sandpipers, curlews and Calidris ferruginea have fallen by around 90%, and those of other waders by 70-75%. The range of species has also narrowed. The estuary is silting up, mangroves are invading and the space where they like to peck or fish is shrinking. We do not know if any measures have been taken since this publication. On the other hand, as a collateral effect of Belal, the 1500 liters of fuel oil accidentally spilled into the river that feeds the estuary must not have helped matters, despite the measures put in place.
Faced with these indicators in the red, we can take comfort in the fact that never before has so much money, through various international or local funds, been devoted to conservation in our country. Vincent Florens is delighted, with certain reservations: “We need to prioritize our actions,” he notes. To solve a large part of our biodiversity problems, most of our efforts should be directed towards real control of invasive alien species in the 8,200 hectares of Mauritian forests. This is financially feasible, and we know that there is very little re-invasion afterwards. In 50 years, we’ve cleared only 5% of these areas! In Mauritius, we’ve always had the means to fight agricultural pests. Couldn’t we put the same energy into fighting the species that threaten the biodiversity of our forests?
Ignorance, the main enemy
Our degraded environment is having an ever-greater impact on everyday life, and this comes at an economic cost. Vincent Florens is convinced: “Some people still believe that conservation is a luxury. But today, opposing development and ecology is a biased perception. It means that we’re supposedly developing today, only to fall flat on our faces tomorrow! Development doesn’t exist if it’s not sustainable and if, at the same time, we’re breaking the planet’s limits.
The first enemy of sustainable development is ignorance… Are we really aware of the ecological value of the island on which we live, the result of thousands of years of geological formation and evolution? You only have to look at the dilapidated state of our natural history museum in Port-Louis to understand how little value is placed on our biodiversity! However, sometimes it’s down to the will of one man, as shown by Odysseo, which the captain of a private group, Michel de Spéville, was keen to offer to the public. This oceanarium, the largest in the Mascarene Islands, has its own marine biology research program, monitors certain species in the lagoon, such as seahorses, and cooperates with other countries in the region. 80% of the aquarium’s visitors are Mauritians or residents of Mauritius, who come to marvel at our aquatic riches. Curiosity is alive and well!
Elsewhere, with samples of over 23,000 flowering plants and ferns, not to mention mosses, algae and other fungi, the herbarium of Mauritius is the largest collection of Mascarene plants in the southern hemisphere! If we add the engravings and drawings of naturalists, these treasures of knowledge could easily feed a museum worthy of our fascinating biodiversity, which would no longer be the sole preserve of scientists… An Occitan poet once said that knowing the names of a country’s flowers allows us to live there in peace. Enabling people to learn about their natural environment is a first step towards protecting it.
Composting and waste sorting
Even on our island, surrounded by “paradise” reefs and lagoons, the sea sometimes regurgitates our rubbish, in a raging return to sender… The 500 tonnes of garbage deposited on the Caudan esplanade after Belal’s passage denounce our little piggy habits, quite clean at home, but very dirty in public spaces… According to the Ministry of the Environment, Mauritius produces 1488 tonnes of solid waste per day, or over 543,000 tonnes per year, buried at Mare Chicose. More than half of this comes from food and gardens. This organic waste clogs up the landfill when it could be composted to enrich farmland. Only 6% of waste is recycled in Mauritius, and only a few private initiatives, such as Moka Smart City, have set up waste collection sites. More good news: Mauritius has banned single-use plastic bags and other packaging since 2021, 12 years after Rodrigues.
Reinforcing reefs
Coastal ecosystem resilience – that’s what the RECOS regional program, which started in 2021, is all about. Supervised by the IOC, its management has been entrusted to the NGO Reef Conservation in the Bel Ombre watershed, which has been identified as a pilot site for implementing a sustainable management plan around the Jacotet River, involving all stakeholders, from the private sector such as the Rogers Group to local communities, NGOs and nature reserves. The site has been assessed, the teams are in place and field activities are due to start this year.
Sustainable agriculture
Initiated by the Mauritius Chamber of Agriculture (MCA), a 2015 survey of 300 vegetable growers showed inaccurate and undocumented use of chemical inputs. The MCA then set up a Smart Agriculture pilot project for vegetable production with small-scale growers in La Laura and Plaine Sophie, as well as 5 major groups. Some twenty hectares were mobilized to implement practices such as crop rotation, service plants to combat pests and diseases, auxiliary insects, organic inputs and chemical inputs used only when necessary. Results: chemical use has dropped by 38% between 2018 and 2021, then by 57% between 2020 and 2022. The 13 growers are now embarking on a certification process, with the Karo Natirel program…
Fishing: pass outside the lagoon
The ECOFISH program aims to make the fishing industry more sustainable, by studying the situation of the profession, observing the evolution of fish resources and protecting them. This program has set up fish aggregating devices (FADs) outside the lagoon, where there are more potential catches, to reduce the excessive pressure on the lagoon. The Ministry of Fisheries began installing such devices around forty years ago. Catches in the lagoon have fallen from 1,500 tonnes in the 1970s to around 300 today. The warming of the surface water means that our fishermen fish deeper, and the size of the fish has diminished. Of the lagoon’s 3,000 fishermen, 300 to 500 are currently able to fish on the FADs. They are also being encouraged to stop seining, even though this technique still accounts for 40-50% of catches.
Green Attitude…
The Attitude group has adopted a position of concern for the marine environment through a number of measures, the latest of which is to distribute Lagoon Attitude, a 100% natural mineral sunscreen with no environmental impact, free of charge to its customers. And it’s made locally! This proposal will be extended to the group. Single-use plastic has been eliminated in all nine hotels by 2020, with bulk products available in the stores, and water bottles and fountains made widely available. These hotels have also stopped motorized activities at sea, such as water skiing.
The microforests of Beau Plan
Novaterra created its first microforest (or tiny forest) in 2022, in the heart of the Smart City of Beau Plan, near Mahogany, with the expertise of botanist Jean-Claude Sevathian and the involvement of its employees. A2nd was created in March 2023, on a 200m2 plot next to the Bois-Rouge soccer pitch, with 400 endemic plants, trees and ferns planted very densely, in keeping with the vision of the concept’s inventor, Japan’s Akira Miyawaki. The project involved the forestry services, villagers, Greencoast students, NGOs and the district council. From now on, the Novaterra group will be helping companies located in the business park to create their own microforests. To sequester carbon, provide shade, coolness and humidity, and above all breathe life into the environment.
The Triton de Pointe d’Esny
After laying the infrastructure for the 70-hectare Village Pointe d’Esny, Groupe Beau Vallon (GBV) last year unveiled a stormwater treatment system designed both to prevent flooding and to filter water before it reaches the nearby mangrove swamp. This residential and commercial site lies at the center of a 12-hectare system of coastal wetlands. Designated an Environmentally Sensitive Area (ESA), it regulates the flow of water between the lagoon and the coast. To ensure that these wetlands continue to play this crucial role, without being impacted by the future village, GBV has installed the Triton system, which revolves around a network of retention basins that capture and filter rainwater, then ensure its slow percolation back to the wetlands. This project benefits from the SUNREF green credit line deployed by AFD (Agence française de développement) through MCB, to encourage adaptation to climate change.
