Burnt pellets complicate impact of plastic spill off Sri Lanka, study finds

  • Volunteers cleaning up after the sinking of the X-Press Pearl in Sri Lanka say they’ve encountered a lot of burnt nurdles, the basic building block of plastic products, during the initial stages of the cleanup operation.
  • A newly published paper highlights how burnt nurdles complicate the environmental challenges — making cleanup operations harder and much more complex, besides proving highly detrimental to marine life.
  • The Sri Lankan government has called on the international community to enact new regulations in shipping transportation, landing and loading in order to reduce the risk of accidents like the X-Press Pearl disaster.

COLOMBO — There was little relief from the scorching sun on the beach, but the volunteers kept at their work, scouring the sand for small plastic pellets known as nurdles.

The nurdles, the basic building blocks for all kinds of plastic items, have fouled a massive arc of coastline along Sri Lanka’s south and west after they fell off the stricken X-Press Pearl cargo ship when it caught fire and sank in May. On the beach, these white pellets have been mixed with darker, natural-looking detritus. The cleanup volunteers initially ignored the latter, but a closer look revealed that these were, in fact, burnt nurdles.

Large nurdle spills due to ship accidents aren’t new, but the X-Press Pearl accident is unprecedented as huge quantities of the plastics were burned in the fire that engulfed the ship.

And while experts had warned of an unprecedented environmental disaster from that initial spill, a newly published paper highlights how burnt nurdles complicate the environmental challenges — making cleanup operations harder and much more complex, besides proving highly detrimental to marine life.

The study, by researchers in Sri Lanka and the U.S., analyzes how the fire could have change the original color, size, chemical properties, bristliness and buoyancy of the nurdles, and how that would modify their impact.

The burnt nurdles come in irregular shapes and are often black in color. Image courtesy of Asha de Vos.

New study on impacts

The Singapore-flagged X-Press Pearl was carrying 1,486 containers, including a cargo of nitric acid and other hazardous chemicals, when it caught fire in May off Sri Lanka’s western coast. With the fire burning out of control, the ship eventually sank about 18 kilometers (11 miles) offshore, and with it the cargo.

This included the estimated 75 billion nurdles that spilled into the ocean or were burned in this single marine accident.

Within five days of the freighter catching fire, the nurdles reached Sri Lanka’s western beaches. Typically white and the size of a pea, they also washed ashore with darker plastic chunks about 6 centimeters (2.5 inches) across — agglomerations of burnt nurdles that had melted together.

“As fire changed the original properties of the nurdles, we believe the burnt nurdles reached the shores faster,” says study co-author Asha de Vos, a marine scientist at the OceansWell marine conservation and research education organization.

The original and burnt nurdles have different floating properties, hence were subjected to different distribution patterns and speeds, with the overall effect being that of two spills rather than one, the study suggests. The larger chunks of melted nurdles are more buoyant than the smaller unburnt pellets, meaning they were pushed to shore faster, the study says.

“The fact that the burnt nurdles may reach the beaches faster could limit the time available for their dispersal, so they will be beached faster. This could be a reason for burnt plastic to be found in some beaches of the western coast,” De Vos told Mongabay.

Volunteers of all ages teamed up for the nurdle cleanup program. Image courtesy of the Pearl Protectors.

A difficult cleanup

Muditha Katuwawala, coordinator of the Pearl Protectors, a marine conservation NGO, says their volunteers encountered a lot of burnt nurdles during the initial stages of the cleanup operation.

The nurdles are often mixed with sand, seashells, and other natural materials on the beaches, making them difficult to collect. Unburnt nurdles are more visible because their white color stands out, but burnt ones are easily camouflaged among natural materials, making them difficult to identify.

“We had to educate our volunteers on this, Katuwawala told Mongabay.

A nurdle portal, to separate the plastic pellets from sand, being used during a volunteer cleanup operation. Image courtesy of the Pearl Protectors.

The study also indicates that the burnt nurdle are more brittle, hence are more easily broken down, such as by wave action, into pieces that are much harder to recognize as a nurdle.

This combination of irregular shapes, color and size means the chances that a burnt piece of nurdle looks like food to a marine animal is higher. Plastic when exposed to fire can also become carcinogenic and have other harmful impacts, so this increases the threat to marine life, De Vos said. The study found that the burnt plastics were three times more chemically complex than the original nurdles.

The X-Press Pearl accident occurred at a time when Sri Lanka was under a countrywide COVID-19 lockdown, preventing volunteer activities. The Pearl Protectors, a youth-led organization, got into action in July, cleaning up the nurdles on the coastline and launching a campaign for a “nurdle-free Sri Lanka.”

“Our volunteers have done weekly campaigns to clean the beaches, and so far we have collected over 1,500 kilograms [3,300 pounds] of nurdles,” Katuwawala told Mongabay.

A beach on Sri Lanka’s western coast is dotted by burnt and unburnt nurdles. Image courtesy of Asha de Vos.

War against nurdles

Dharshani Lahandapura, chair of Sri Lanka’s Marine Environment Protection Authority (MEPA), said a salvage operation for the X-Press Pearl is expected to start next month. An expert panel submitted two interim claims from the ship’s owner, with Sri Lanka receiving approximately $3.6 million to date in damages.

“Our expert panel is still evaluating the environmental impacts of the ship disaster and are considering the potential for long-lasting impacts,” Lahandapura told Mongabay.

The Sri Lankan government has called on the international community to enact new regulations in shipping transportation, landing and loading in order to reduce the risk of accidents like the X-Press Pearl disaster, which unleashed multiple forms of pollution. Lahandapura said the MEPA has submitted a proposal in the issue to the International Maritime Organization (IMO), which is due to be discussed at the Maritime Environmental Protection Committee meeting next year.

 

Citation:

De Vos, A., Aluwihare, L., Youngs, S., DiBenedetto, M. H., Ward, C. P., Michel, A. P., … James, B. D. (2021). The M/V X-Press Pearl nurdle spill: Contamination of burnt plastic and unburnt nurdles along Sri Lanka’s beaches. ACS Environmental Au. doi:10.1021/acsenvironau.1c00031

 

 

Banner image shows how the white pea-shaped nurdles mix with the burnt ones, turning them into black nurdles, courtesy of Asha de Vos.