Marine researchers find biggest source of microplastics in our ocean

23 mins ago
Microplastic waste found within the seaside sand.

Marine researchers in Auckland have discovered what is making up the majority of microplastics in New Zealand's ocean.

They found tiny pieces of vehicle tyres were polluting coastal waters and almost half of the rubber that shed on our roads ended up on the environment.

The tyres contributing most to the problem were found on both EVs and utes.

Dr Samantha Ladewig, a marine microsplastics researcher at the University of Auckland, told Checkpoint, the size of the particles could get down to nano size and could not be seen with a microscope, while larger fragments could be as big as one to two millimetres.

Ladewig said there were very few stormwater treatment devices that were able to capture such tiny particles which would go directly from our roads through a stormwater pipe and into the coast.

"Over time you may realise your tyre tread reduces in size and that material goes onto the roadways and half of it ends up staying there and the other half goes into our environment."

Ladewig said this amounted to about 5000 tonnes going into the environment every year.

She said the study looked at a few bays in Auckland including Coxs Bay and Saint Marys Bay.

"We tried to sample areas that were right next to the road or by a motorway, and I can confirm we saw them [tyre particles], in every single spot in both the roadside sediment and the coastal sediment."

The research lab was exploring what that would mean for marine life and found the particles were being picked up and eaten.

"Even our selective feeders are eating them too... these particles and the chemicals attached to them can change the way our ecosystems work and support us."

Ladewig said there were a range of solutions to look at and noted it was an issue worldwide.

"Other places around the world are starting to think about this too... It's thinking about the design of these tyres and looking at stormwater treatment devices that can filter out these fine materials."

rnz.co.nz

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