Plastitar: mix of tar and microplastics is new form of pollution, say scientists

Researchers in Canary Islands coin term for new type of marine pollution they say could be leaking toxic chemicals into oceans

The discovery came as a team of researchers were combing the shores of the Spanish island of Tenerife in the Canaries. Time and again, set against the sparkling waters that lapped the Playa Grande, they spotted clumps of hardened tar, dotted with tiny, colourful fragments of plastic.

They swiftly realised that this combination of tar and microplastics – or “plastitar” as they named it – was unlike any other plastic pollution they had seen.

“No longer is the presence of plastic in the environment limited to microplastics or a bottle in the sea,” said Javier Hernández Borges, an associate professor of analytical chemistry at the University of La Laguna in Tenerife, who coined the term plastitar. “Now it’s giving rise to new formations; in this case, one that combines two contaminants.”

A close-up of tar containing tiny pieces of plastic as well as a strand of nylon ope
The plastitar also becomes embedded with microplastic fragments far smaller than this strand of nylon rope. Photograph: AChem Research Group, University de La Laguna

More than two years after researchers stumbled across it, the find has been captured in new research that describes it as an “unassessed threat” for coastal environments. It adds to a growing list of marine pollution fashioned out of plastic, from pyroplastics – melted plastic that takes on the appearance of small rocks – to plastiglomerates, formed from a combination of melted plastic, beach sediment and basalt lava fragments.

When it comes to plastitar, its formation is simple: as residue from oil spills in the ocean evaporates and weathers, it washes ashore as tar balls that cling to the rocky shores of the Canary Islands. “It acts like Play-Doh,” Hernández Borges said. “And when waves carrying microplastics or any other kind of marine debris crash on to the rocks, this debris sticks to the tar.”

As time goes on, the formation hardens, with everything from bits of discarded fishing gear to plastic pellets and remnants of polyester and nylon becoming fused to the tar.

The researchers found plastitar along the shorelines of several islands in the Canaries, including El Hierro and Lanzarote. It was widespread, in one case stretching across more than half of the area they were examining. The team linked its presence to the archipelago’s location along a key shipping route for oil tankers but they have little doubt that plastitar exists around the world.

“We’re convinced that this is probably found wherever you see this combination of tar – which unfortunately remains common on beaches – and microplastics,” Hernández Borges said.

While more research needs to be done to confirm plastitar’s impact on the environment, researchers believe that its combination of hydrocarbons and microplastics means it will potentially leak toxic chemicals, causing conditions that could prove deadly for organisms such as algae.

“In some way, it may be blocking and inhibiting the development of the ecosystem,” Hernández Borges said.

The discovery feeds into the emerging picture of a global plastic cycle, with plastic moving through the atmosphere, oceans and land in a way that echoes natural processes such as the carbon cycle.

“There are researchers who are talking about the fact that plastic is so pervasive that it could be affecting our environment in other ways,” Hernández Borges said. “So if plastic is giving rise to other formations, this is extremely important.”


Ashifa Kassam in Madrid

The GuardianTramp

Related Content

Article image
Nurdles: the worst toxic waste you’ve probably never heard of
Billions of these tiny plastic pellets are floating in the ocean, causing as much damage as oil spills, yet they are still not classified as hazardous

Karen McVeigh

29, Nov, 2021 @7:15 AM

Article image
Recycled regatta: world heritage site highlights plastic pollution crisis
When environmentalists on a Seychelles atoll decided to race boats made from ocean litter, they had 500 tonnes to pick from

Anne Pinto-Rodrigues

03, Dec, 2021 @7:00 AM

Article image
NGO retracts ‘waste colonialism’ report blaming Asian countries for plastic pollution
Ocean Conservancy apologises for ‘false narrative’ of 2015 study that put blame for bulk of world’s plastic waste on five Asian states

Karen McVeigh

15, Sep, 2022 @10:05 AM

Article image
More than 100 nations take action to save oceans from human harm
Envoys at Brest summit sign up to measures to tackle fight against illegal fishing and cut pollution

Jon Henley

11, Feb, 2022 @5:37 PM

Article image
Meet Mr Trash Wheel – and the other new devices that eat river plastic
From ‘bubble barriers’ to floating drones, a host of new projects aim to stop plastic pollution before it ever reaches the ocean

Russell Thomas

11, Jan, 2022 @8:15 AM

Article image
US cruise ships using Canada as a ‘toilet bowl’ for polluted waste
Lax Canadian regulations create ‘perverse incentive’ for US cruise ships en route to Alaska to discharge toxic mix of chemicals and wastewater off British Columbia, report says

Richa Syal

09, Jul, 2022 @12:00 PM

Article image
‘Oil spills of our time’: experts sound alarm about plastic lost in cargo ship disasters
Sri Lankan beaches buried in pellets only ‘tip of the iceberg’ of environmental harm after analysis of nurdles from burning ship

Karen McVeigh

09, Feb, 2022 @12:41 PM

Article image
Plastic summit could be most important green deal since Paris accords, says UN
World leaders to gather in Nairobi next week to discuss first global treaty to combat plastic waste

Karen McVeigh

25, Feb, 2022 @6:01 AM

Article image
Pathogens hitchhiking on plastics ‘could carry cholera from India to US’
Research finds ‘nurdles’ washed up on Scottish beaches tainted with E coli, with potentially far-reaching health implications

Karen McVeigh

11, Mar, 2019 @12:06 PM

Article image
Amazon shareholders to vote on revealing retailer’s plastic footprint
Move follows report saying online retailer generated 210,000 tonnes of packaging that ended up in oceans

Karen McVeigh

26, May, 2021 @5:00 AM