- In 2020, amid the chaos of the pandemic, the island nation of Mauritius was hit by one of the worst environmental disasters in its history when the MV Wakashio, owned by Nagashiki Shipping, crashed into the coral reef barrier off the southeastern part of the island.
- The ship spilled around 1,000 metric tons of oil into the waters near three sites of ecological importance; more than five years on, conservationists and fishers say the Mauritian government quietly allowed the entire episode to fade from public memory, with little scrutiny.
- When Mongabay visited mangroves in 2025 that had been affected by the oil spill, fuel oil still lingered in the water-soaked earth; it could persist for decades, experts warn.
- Vikash Tatayah at the Mauritian Wildlife Foundation facilitated the evacuation of animals considered at risk due to the oil spill, including lesser night geckos, to the U.K.; eggs from the geckos and their descendants were returned to Mauritius in 2025.
POINTE D’ESNY, Mauritius — In August 2020, Vikash Tatayah at the Mauritian Wildlife Foundation made a phone call he never expected to make. He had “an unusual request,” he recounts telling friends in the U.K. who owned a private jet: A bunch of geckos needed to be evacuated.
Mauritius had just entered COVID-19 lockdown, its airspace was closed, so it would have to be a special flight. Amid the chaos of the pandemic, the island nation had been hit by one of the worst environmental disasters in its history. On July 25, the MV Wakashio crashed onto coral reefs off Mauritius’ southeastern coast, later spilling around 1,000 metric tons of oil.
In time, the slick spread north, creeping to the islets that line the coast. These are home to threatened lesser night geckos (Nactus coindemirensis), prompting Tatayah to call for their evacuation. The oil spill occurred near Blue Bay Marine Park, a coral hotspot, and two other protected sites: the Pointe d’Esny Wetland (a Ramsar site blessed with rich mangroves ) and the Ile aux Aigrettes Nature Reserve.
Oil started leaking from the ship in the first week of August. On Aug. 15, the Wakashio broke in two. In the days following the spill, ocean currents nudged the floating oil northward toward Vieux-Grand-Port. At its most expansive, the oil spill covered nearly 30 square kilometers (11.6 square miles) of coastal waters.
A government-appointed group estimated that the shipwreck and oil spill affected 96 km2 (37 mi2) of coastal and marine habitats, including corals, seagrasses, mangroves and intertidal mudflats.
More than five years on, oily residue still clings to the roots of mangroves fringing the eastern shore. Meanwhile, fishers still wonder if the oil leak could have been prevented had the government acted swiftly to remove the stranded ship.
Mauritians also still have unanswered questions about the deaths of around 50 dolphins that washed up days after the spill. The report linked the deaths to a hydrographic survey conducted by a government body at the request of the shipowners’ agents. People still recoil at the memory of the stench that clung to the shore, and experts wonder how prepared Mauritius, which lies on a major global maritime trade route, is for another shipping disaster.
The bulk carrier, MV Wakashio, a workhorse of commercial fleets that sustain the global trade in commodities, was making its way from China to Brazil with 20 crew members. It had 3,894 metric tons of fuel oil, 207 metric tons of diesel and no cargo on board when it crashed.
“I thought, bloody hell. It is in our backyard,” Tatayah, a biologist and MWF’s conservation director, said of the shipwreck. Tatayah described his fears about how the oil spill would impact unique and threatened wildlife that inhabit the coastal islands, including the lesser night geckos, found only on four islets in Mauritius. They are considered vulnerable by the IUCN.
The geckos made their departing flight. After jumping through several administrative hoops, a jet from Mauritius reached the U.K. with 30 lesser night geckos on board.
1. The dodo and the cricket
Mauritius, located off the southeastern coast of Africa, is part of the Madagascar and Indian Ocean biodiversity hotspot. The main island is surrounded by four dozen islands and islets, including Ile aux Aigrettes off the southeastern coast, which is under the care of the MWF.
The sobering reality of how Homo sapiens can extinguish other denizens of the planet is hard to escape on the Ile aux Aigrettes. The Sentier of the Dodo, a path named for the extinct flightless bird, loops around the island. Along the way, visitors encounter bronze statues of extinct creatures like, of course, the dodo (Raphus cucullatus), but also the Mauritius scops owl (Otus sauzieri) and the giant skink (Leiolopisma mauritiana). Each one is a reminder of humanity’s toll on the planet.
Among the current inhabitants of Ile aux Aigrettes is a giant tortoise (Aldabrachelys gigantea) called Big Daddy, who is reported to be more than 100 years old. According to human lore, he has lived through much — but not an oil spill. Feathered-folk include the pink pigeon (Nesoenas mayeri), a bird endemic to Mauritius, which was recently brought back from the brink (at its lowest, their population consisted of just 12 individuals).
But when Tatayah heard of the spill, near the top of his worry list was a humble cricket, which (unbeknownst to it) had still not been recorded in the annals of modern science. Researchers armed with headlamps captured specimens in the crevices of the limestone cliffs on the Ile aux Aigrettes, where they hide during the day.
“You’d better describe it now,” Tatayah recalled telling Sylvain Hugel at the University of Strasbourg, who was studying the insects at the time. “There is a chance the cricket might vanish if the worst comes to pass as a result of the oil spill.”
2. ‘Like a petrol station’
The U.K.-bound geckos escaped not just the oily mess but also its stench.
“The beaches, even the jetty over there, were black with oil,” Tatayah said, pointing to the jetty of the Ile aux Aigrettes. “It smelt like a petrol station.”
The MV Wakashio was running on very low sulphur fuel oil (a relatively new type of fuel) when the shipwreck occurred. Nagashiki Shipping, a Japanese company, owned the Panama-flagged vessel. Another Japanese company, Mitsui O.S.K. Lines, chartered it, employing a crew mostly hailing from South and Southeast Asia. The British oil giant BP supplied fuel oil to the Wakashio.
“Oil is made of tens of thousands of individual compounds. In the first couple of hours, the lighter compounds will basically evaporate into the atmosphere,” said Alan G. Scarlett, an environmental geochemist at Curtin University in Australia. Scarlett and his team published one of the few independent studies documenting the oil spill’s impacts.
Sandy Monrose, who hails from a family of fishers and lives a stone’s throw from the waterfront near Pointe d’Esny, still remembers the smell. She remembers the oily odor invading her house, especially at high tide when the wind carried the fumes toward the shore. She remembers hesitating to light a match, afraid it might cause an explosion.
Still, the stench did not prevent Monrose and others from joining the cleanup efforts. “We wanted to protect our sea,” she said.
In the days following the oil spill, the internet was abuzz with reports of how Mauritians had come together, armed with homemade booms, to keep the oil from reaching their coast.
“If that spill had happened in Australia, the government agencies would have come in. They would have cordoned off the area [and] made sure no public came in,” Scarlett said, adding, “In Mauritius, there was no plan. Local people just waded in trying to deploy those homemade booms.”
Under the circumstances, however, the involvement of residents in Mauritius appeared almost inevitable. It is quite “customary” for local people to be involved in cleanups because they are there, in the country, Tatayah said. What’s more, with COVID-19 restrictions in place, they couldn’t get international teams to come immediately, he said.
This swell of support did create complications. “It was unfortunately difficult to prevent hurting the coral, because we used rocks to anchor [the booms]. We needed to put them on the corals, not the sand,” Monrose said.
Monrose suspects the days spent working to clean up the oil had consequences for people’s health. “We are still worried about our health. We didn’t have any tests. Nothing has been done,” she said.
3. ‘There was Wakashio oil here’
The smell of the oil spill is confined to the memory of many, but there is one place that scientists know where you can still encounter the stench, even five years on: the swampy mangroves of Vieux Grand Port. Scarlett and his team analyzed soil samples from here in March 2023. His team used chemical analysis, comparing the chemical signature of the Wakashio oil to that found trapped in the mangrove roots. They published their findings in Marine Pollution Bulletin confirming the ongoing presence of oil from the doomed ship.
Two years later, on a rainy June morning, Mongabay visited the area with Sébastien Sauvage, CEO of the NGO Eco-Sud Mauritius.
There are patches of the submerged land where the water oozing from the rain-soaked earth is iridescent. “There was Wakashio oil here,” Sauvage said, scooping up muddy goop in a plastic spoon and taking a sniff. It smells unmistakably of fuel oil.
“The ongoing presence of the oil could still pose an unknown risk to the sensitive mangrove ecosystem,” Scatlett said in a statement when the study came out. “Our modelling suggested more of the Wakashio’s fuel would evaporate, naturally disperse or sink compared to traditional fuels, but assessing the impact on organisms remains challenging.”
Scarlett said his team was no longer studying the oil spill’s impacts but added that “once it’s buried in the sediment, the oil kind of just stays there; it can stay there for decades.”
These mangroves serve as a shelter for crabs and as nurseries for fish. Serge Simon Vurdapa Naicken, 72, who has been fishing in the waters near Pointe d’Esny for five decades, worries about the impact on fisheries. He has seen firsthand the injury to the corals.
“The coral reefs are still degraded,” Naicken said. He pointed to the proliferation of algae around the Ile aux Aigrettes as a sign of poor coral health. Often when corals die, algae colonize the dead or damaged reefs. Mauritius has also seen a major coral bleaching episode post-Wakashio, due to the overheating of seawaters in 2024, extending into 2025.
“It is not the same. I don’t think the ecosystem will recover,” Naicken said.
4. Dead dolphins
It is not just the smell of Wakashio oil that remains seared in Monrose’s memory; it is also the image of dead dolphins. She pulls up photos on her phone. “I went to see them, but I did not return [to the spot],” she said, reliving the pain of seeing the dying and dead animals that became stranded on the coast in southeast Mauritius days after Mauritius decided to sink the forward half of the ship.
The sinking operation was completed Aug. 22. Four days later, around 50 dolphins and melon-headed whales (Peponocephala electra), which are members of the dolphin family, washed up dead along the southeastern coast near the near the Grand Sable area.
The occurrence of the two events so close together in time has sparked a great deal of speculation.
Environmental organizations, including Greenpeace, called for a thorough investigation into whether the strandings were related to the shipwreck and oil spill. One theory circulating among the residents suggested that the explosion that sank the ship’s bow may have been responsible.
Preliminary examinations did not detect hydrocarbons in their lungs, but residents remarked on the wounds on the carcasses. Cetaceans are sensitive to underwater noise; an explosion at sea could disorient them. The wounds could be from traversing the coral reef barrier, which fringes the coast, while disoriented, Naicken said.
The government-appointed expert group, however, pointed to another probable cause linked to the Wakashio cleanup. They drew attention to two hydrographic surveys using multibeam echosounders conducted near the shipwreck.
A survey conducted Aug. 22 by the Hydrographic Unit of the Mauritius Ministry of Housing and Lands was the “the probable cause” of the strandings, the report said. The sonar exposure likely caused ear damage, leading the whales to become disoriented, strand and die. The survey was conducted at the request of the shipowner’s agents, as part of the effort to sink the ship’s forward section.
5. Like ‘nothing happened’
Conservationists like Sauvage say the Mauritian government has quietly allowed the entire episode to fade from public memory, with little scrutiny. A sentiment echoed by Monrose. It’s like “nothing happened,” she said.
More than five years on, there is no clarity on what caused the oil spill, very little publicly available research on the impacts, and fishing communities are still waiting for adequate compensation.
In the initial weeks following the oil spill, there was reason for the government to remain tight-lipped to curb panic, Scarlett suggested. “When you have a lot of publicity, the pictures of the oil, the birds, those images strike people. It tends to put off tourists. It also frightens people. The economic harm is worse from the reporting of it than what’s actually caused by the oil,” he said.
“A spill of that size in Europe or America probably would have got a hell of a lot more publicity. In a small island in the Indian Ocean, I’m afraid nobody gives a damn,” he added.
The Wakashio was flagged to Panama, a country in Central America, and hence subject to rules and regulations of that country.
A 2021 report from Panama’s Maritime Affairs Investigation Department identified the ship captain’s decision to change course, bringing the ship dangerously close to Mauritian shores (within 5 nautical miles) in order to get access to Wi-Fi signals as a major factor for the grounding. In 2021, a Mauritian court sentenced the captain and first officer of the Wakashio to 20 months for endangering safe navigation.
However, the circumstances under which the officers submitted their guilty pleas remain murky. Advocacy groups decried the treatment of the Wakashio crew, describing it as “criminalization of seafarers.”
“We know that seafarers are seen by some officials as convenient bargaining chips in efforts to hold shipowners to account for maritime accidents caused by issues like a lack of maintenance,” the Seafarers International Union said in a statement, adding, “This is especially the case when a state finds it difficult to locate and prosecute irresponsible shipowners who too often hide behind the Flag of Convenience system.”
Panama is widely considered a Flag of Convenience, a system that allows shipping companies and ship owners to avoid stricter regulations in their home countries. A vessel flagged to Panama is subject to the laws of that country.
The government-appointed Court of Investigation report, published in October 2025 with little media attention, also focused on human error as the cause for the tragedy. But, it also highlighted institutional and regulatory failures, especially in coastal surveillance and emergency response.
Following the findings of the Court of Investigation, Mauritian authorities opened a police investigation into the local agencies.
The oil spill could have been prevented, Naicken said. “The government took a lot of time.”
While the ship’s bow was scuttled, its stern, which was stuck on the reef, was dismantled over the course of 1.5 years.
6. ‘Silver lining to the cloud’
But the threat of an oil spill in Mauritius has not disappeared with the Wakashio.
“With so many ships passing by Mauritius, the risk is not gone. It can be anywhere, anytime,” Tatayah said.
Mauritius sits on a shipping route connecting manufacturing hubs in East Asia with other markets as far afield as Europe and North America. One shipping industry insider described Mauritius as being on the ‘highway’ of international shipping.
In the aftermath of the oil spill, the Mauritian government heeded calls from conservationists, including Tatayah. It began the process of establishing Particularly Sensitive Sea Areas (PSSAs) and Areas to be Avoided (ATBAs). Such designations restrict ship movement in dangerous-to-navigate areas or where there is potential for serious environmental damage.
In 2022, the Mauritian government partnered with JICA, Japan’s aid agency, on a program to better prepare its institutions to respond to oil spills.
But significant gaps remain in the publicly available information about the oil spill. The Mauritian government did not respond to Mongabay’s requests for comment.
“The question I would ask myself is if the same thing happened again, would it just all repeat itself?” Scarlett said.
“Mauritius is now a bit better prepared,” Tatayah said. “So that’s probably the silver lining to the cloud.”
7. A cricket is named; gecko eggs come home
There was progress on other fronts: The shy crickets were fast-tracked to scientific description. A 2021 paper proposed a new species, Makalapobius aigrettensis.
“The population of this remarkable species appears to have been directly impacted by the ecological disaster caused in August 2020 by the sinking of the tanker Wakashio,” the paper in the journal Zootaxa noted. “Due to their narrow habitat in the intertidal area, sea water pollution should be considered as a major threat to Burcini [a taxonomic group of crickets including the M. aigrettensis].”
As for the evacuated geckos, they have spent the last five years in the care of the Durrell Wildlife Conservation Trust at Jersey Zoo in the U.K. Under the Mauritius Island Restoration Programme the trust partnered with MWF, Mauritius’ National Parks and Conservation Service, the country’s forestry department and the Luxembourg-based Jean Boulle Group to keep the geckos safe and provide conditions for them to thrive, away from home.This was an “assurance population” in case their counterparts in their original homeland disappeared.
Monitoring in Mauritius showed that, after the oil spill, the genetic diversity of the native population decreased.
The oil spill both directly and indirectly impacted the local gecko population, according to Tatayah. “There was actually oil on the geckos; they were ingesting oil through their food,” he said. “The indirect effect on them is through the food chain; because oil spills affect insects.”
The geckos in the U.K., though, appear to have maintained their genetic diversity. So, in January 2025, 57 lesser night gecko eggs traveled from Jersey Zoo to London’s Heathrow Airport and then on to Mauritius in a carry case, where temperatures were maintained at a snug 20° and 25° degrees Celsius (68° and 77° Fahrenheit).
They were released on the islet of Ilot Vacoas. In December, Durrell dispatched another 142 eggs to their native island home.
Citations:
Scarlett, A. G., Nelson, R. K., Gagnon, M. M., Reddy, C. M., & Grice, K. (2024). Very low sulfur fuel oil spilled from the MV Wakashio in 2020 remains in sediments in a Mauritius mangrove ecosystem nearly three years after the grounding. Marine Pollution Bulletin, 209, 117283. doi:10.1016/j.marpolbul.2024.117283
Hebbar, A. A., & Dharmasiri, I. G. (2022). Management of marine oil spills: A case study of the Wakashio oil spill in Mauritius using a lens-actor-focus conceptual framework. Ocean & Coastal Management, 221, 106103. doi:10.1016/j.ocecoaman.2022.106103
Hugel, S., & Desutter-Grandcolas, L. (2021). New intertidal crickets from Comoros and Mascarene Islands (Orthoptera: Trigonidiidae: Nemobiinae: Burcini). Zootaxa, 4995(1), 1-26. doi:10.11646/zootaxa.4995.1.1
Scarlett, A. G., Nelson, R. K., Gagnon, M. M., Holman, A. I., Reddy, C. M., Sutton, P. A., & Grice, K. (2021). MV Wakashio grounding incident in Mauritius 2020: The world’s first major spillage of very low sulfur fuel oil. Marine Pollution Bulletin, 171, 112917. doi:10.1016/j.marpolbul.2021.112917
Banner image: A file photo of the Wakashio shipwreck from 2020. Image by imo.un via Wikimedia Commons (CC BY 2.0).
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