For almost two weeks, a thick, black smudge stained the sky off Sri Lanka’s western coast — smoke from a burning container ship nine nautical miles out to sea.

The Singapore-flagged X-Press Pearl caught fire on May 20 en route to Colombo carrying 350 metric tons of oil in its tanks and at least 81 containers of “dangerous goods,” including nitric acid — a highly toxic chemical used to make fertilizers.

As the Sri Lankan navy and coast guard teams fought to douse the flames, the inferno tore through the ship’s cargo, releasing a cocktail of hazardous chemicals into the air and sea, prompting authorities to issue a toxic rain alert, and compounding fears of an oil spill.

The fire released 80 tons of plastic pellets — raw materials used to make plastic products — into the ocean, blanketing beaches along Sri Lanka’s western coast. The environmental impact was immediately clear.

Plastic pellets became lodged in fish’s gills and mouths. And dozens of rare sea turtles washed up on Sri Lanka’s beaches, some with what appeared to be scorch marks on their shells. Fish, dolphins and even a whale were found dead. As of late June, about 200 carcasses had been counted.

Two months on, billions of plastic particles have washed up on nearly every shore of the island and are expected to disperse throughout the Indian Ocean.

Fishing communities have been heavily impacted, and locals fear it will be take years for the island to recover from what environmentalists have called the worst disaster in Sri Lanka’s history.

Sri Lanka is a tourist hotspot. Its unspoiled beaches and turquoise waters not only attract tourists, they are home to abundant sea life, including 28 species of marine mammals, such as blue whales and five species of endangered nesting turtles.

It is not unusual for marine animals to wash ashore at this time of year, after becoming entangled in fishing nets or simply victims of the rough monsoon seas. While no records were kept of how many dead animals washed ashore in previous years, local environmentalists say this time is different.

“We are seeing this exponential increase of marine deaths, including dolphins, turtles. What is noticeable is the exponential increase started soon after this accident,” said Don Muditha Katuwawala, coordinator for Sri Lankan marine conservation group Pearl Protectors. “We are seeing 30 to 40 cases reported daily.”

Thushan Kapurusinghe, a turtle conservationist with 28 years’ experience who helped establish Sri Lanka’s first marine turtle sanctuary, believes the deaths were caused by the ship disaster.

Usually, if a turtle was caught in a net or rough seas, Kapurusinghe said, you’d see cut marks on their fins or broken shells. Often they are bloated from weeks in the water or have bite marks from other predators, he said.

But the turtles he has seen on the beaches, and in photos sent to him from residents, had apparent scorch marks on their shells, swollen eyes and salt glands, and red engorged blood vessels and legions around their mouths and bellies, he said.

“What you can see with most of these turtles found along the beaches in recent weeks, particularly after the X-Press Pearl disaster, these are fresh specimens,” he said. “Now when you see newly dead carcasses, there are clear burn marks on top of the shell … Around the mouth you can see red patches and bleeding, that means internally they are bleeding.”

He said this suggests they may have been exposed to chemicals or injured in the fire.

Sri Lanka is home to leatherback turtles, green turtles, loggerheads, hawksbill and the small Olive Ridley turtle. Kapurusinghe, the conservationist, said most of the turtles washing up are the latter — among the world’s smallest sea turtles.

From images he’s seen, most are juveniles, which spend their days feeding in the shallower waters close to the western coast, he said.

While nesting sites are found all over the coast, turtle migration and nesting routes, he said, start at the southern coast and make their way north up Sri Lanka’s western coast between March and July. The carcasses were found on beaches around the capital Colombo — up the western shoreline — where the ship was.

“This is not normal. When you observe them you can say they did not die because of becoming tangled in fishing nets,” he said.

Several prominent marine biologists have warned against jumping to conclusions about the animal deaths and urged the community to wait for necropsies — examinations of the carcasses — to be completed, though it is unclear when that will be.

Other factors could be at play in the deaths, including reporter bias, when people are more likely to note carcasses as they’re acutely aware of the disaster.

Ultimately, no one can be sure what is causing the deaths, said Katuwawala of Pearl Protectors, and a lack of comparable data is adding to the confusion.

“We don’t have a proper base-line data that we can compare to previous years. Because of the lack of it and the delays in the post-mortems there is a lot of confusion as to understanding why these marine deaths are happening,” he said.

“All this needs to be accounted for and tested as to how they died and what really caused this disaster for them.”

Sri Lanka’s fisheries were also deeply affected. In some areas they were closed, worsening the financial losses from communities already suffering from pandemic lockdowns.

Fear and confusion spread over whether the fish were safe to eat.

“We also heard about what was in the ship and the chemicals, so we are scared. So now for weeks we have not consumed any seafood. The fishermen are saying its safe. But there is no guarantee,” said Sarika Dinali, a resident from Negombo beach.

D.S. Fernando, a fisherman also in Negombo, said “now the situation is even worse.”

“People are now scared of eating fish because it might be contaminated. Prices have also dropped drastically. The situation is hopeless,” he said.

Others have urged the government to speed up testing on samples and be clear with the public.

“We are most affected because people are refraining from buying fish. It is the government’s responsibility to do proper tests and educate the public on what’s going on. Otherwise people are afraid to consume fish,” said local fishing community leader Aruna Roshantha.

The Sri Lankan government, Department of Fisheries and the MEPA have not responded to CNN’s requests for comment.

On July 11, state Fisheries Minister Kanchana Wikesekera said Rs 420 million ($2.1 million) in compensation will be paid to fishermen as part of an interim claim from the X-Press Pearl.

On July 12, X-press Feeders said made an initial payment, through the vessel owner’s P&I insurers, of $3.6 million to the Sri Lankan government to help compensate those affected by the consequences of the fire and sinking of the vessel.

As communities wait for answers, government and environmental investigators are determining the extent of the disaster.

Independent and international oil experts are on site trying to ensure any oil remaining on the half-sunken ship does not spill into the environment, causing further disaster.

“We continue to contribute to the cleanup and pollution mitigation efforts, having flown in additional oil spill response assets on a chartered flight from Singapore in response to a request from the UN-EU team in Colombo,” the ship’s operators said in a statement.

Salvors remain at the wreck site on a 24-hour watch “to deal with any debris and report any form of a spill with drones deployed daily to help with the monitoring activities,” it said.

Investigations into what caused the fire are ongoing, but the boat had one container of nitric acid — a highly toxic chemical used to make fertilizers — that was leaking.

The captain of the ship, Vitaly Tyutkalo was arrested on June 14 and later released on bail, according to police spokesperson Deputy Inspector Ajith Rohana. He has been accused of allegedly violating the country’s Marine Environment Pollutions Act but hasn’t been formally charged.

The government has named another 14 people as co-accused in cases over the damage caused, according to Reuters.

Meanwhile, the Centre for Environmental Justice has filed a fundamental rights petition in the Sri Lankan Supreme Court.

For decades, de Vos has been pushing for greater rules on ships that pass by Sri Lanka’s waters as part of her work to protect non-migratory blue whales.

The southern coast of Sri Lanka is the main artery through the Indian Ocean, and one of the busiest shipping lanes in the world.

Pushing such lanes farther out to sea or shift to cleaner fuel could help to avoid further disasters, de Vos said, and help safeguard the future of endangered turtles, too.

“The shipping lanes were put in place at a time when we didn’t have this wealth of knowledge about species and how they use these areas, or about safety concerns,” said de Vos.

“And now we do have to use the best available information, to try to understand how we can coexist in a way that will make sure that we’re doing a better job and looking after oceans.”

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