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.

Animal deaths

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."

Plastic disaster

While necropsies are being carried out, Sri Lankans are still collecting tons of plastic pellets released during the fire.

In the weeks after the fire, the surf, whipped up by monsoon seas, became thick with these white plastic pellets, also known as nurdles. The volume was so great that, in some areas, they washed up in knee-deep piles, with each wave bringing millions more ashore.

When Asha de Vos, a marine biologist and founder of Sri Lankan NGO Oceanswell, saw the plastic pollution inundate the shores near her home, she started calling experts to figure out what was going to happen next.

Lockdown prevented residents from going to the beaches to help out with the response, but they could assist in other ways, she said.

"I could feel people's frustration," de Vos said. Her team set up a "nurdle tracker" so the community could send in photographs of what the beaches looked like before and after the plastic. The result exceeded expectations: "We got around 120 people sending photographs within a few days of the entire coastline," she said.

The next step was to figure out where the nurdles were going and create models to track their distribution around the island. People would send in images of beaches where they spotted the plastic, with dates and times.

Together, they were quickly able to build a picture of how far and wide the plastic was traveling and plan to conduct monthly surveys on the concentration of plastic in certain areas and how it changes over time.

One thing stood out. Among the white pellets they noticed some pieces had burned and fused in the fire, something they hadn't seen in previous similar disasters and could increase the danger to the marine environment from potential toxins.

"If we can try to understand the degradation of these nurdles, what's going to happen to them, scientifically, then we have a sense of, okay, how long is this impact going to last? How long can we predict these impacts are going to be?" de Vos said.

The problem is they just don't know how much plastic was released into the water, and how much remained on the ship. "It's still very patchy, and it's still hard for us to really have a lot of those answers," she said.

The country's Marine Environmental Protection Authority said in June it had removed 1,000 tons of debris along 200 kilometers (124 miles) of the coastlines, a triumphant, yet incremental portion of the total spillage.

Lessons from Durban

Experts warn the pellets will wash up for years to come and become a permanent part of the currents and tides of the world's oceans.

In a similar disaster in South Africa in 2018, 49 tons of plastic nurdles spilled into the sea around Durban. A year after the spill, pellets were found more than 4,000 kilometers (2,485 miles) away on St Helena island in the middle of the Atlantic Ocean and two years later on shores of Western Australia, more than 8,000 kilometers (4,970 miles) away.

Charitha Pattiaratchi, an oceanography professor with the University of Western Australia, said the pellets were the main pollutant from the ship disaster as "any of the other chemicals, even if they fell into the ocean would have diluted very quickly."

The plastic, he said, while not necessarily toxic, will remain in the ocean for years.

"The nurdles will continue to be present in the surface waters of the Indian Ocean for many decades and will make landfall in many of the Indian Ocean countries (for example in Indonesia, India, Maldives, and Somalia) because of the reversing monsoon currents in the region," Pattiaratchi said.

Using high-resolution modeling, his team have been able to plot the course of the nurdles' journey over the past two months.

Pattiaratchi said over time the nurdles will grind down to become microplastics, and plastic from the Durban incident is still found on the beaches of Western Australia. "If you go to the beach, you will find them if you're looking for them. And that's what will happen to these ones, it will be distributed along the most of the Indian Ocean, northern Indian Ocean countries, if you go looking for them, you will find them for years to come."

While the pellets are not necessarily toxic to humans, Pattiaratchi said they can further impact marine life by getting trapped in gills of fish, causing them to suffocate.

Fisheries devastated

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.

Investigation ongoing

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.

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.

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."

For de Vos, community involvement is key to recovering from the disaster.

"We come from a small island where fishing is what you use the ocean for. Recreational conservation wasn't a big theme, traditionally. And so to shift that we need to give more people have the opportunity to engage."

"I want to make sure the public is also well informed and not misinformed," she said. "And that that is something that can happen in a crisis situation," she said.