By Erica Mather 10/05/2016 2


The New Zealand shoreline is being clogged with microplastics.  A new study by the University of Canterbury reveals that the high quantities of microplastics found in coastal environments is comparable to levels identified overseas, which is surprising given New Zealand’s geographical isolation.

Microplastics are small plastic particles less than 5mm in size that are found in exfoliant facial scrubs and toothpaste, or originate as larger plastic waste.  The increasing accumulation of microplastics on coastlines is a problem globally as they are slow to breakdown (years to decades).  Their prevalence poses risks for aquatic wildlife as they are easily mistaken for food and ingested by birds, fish and plankton – causing serious internal damage.  Microplastics can also absorb high concentrations of harmful pollutants such as DDT, which can be passed up through the food chain to humans.

The study, published this month in the New Zealand Journal of Marine and Freshwater Research by University of Canterbury (UC) PhD student Phil Clunies-Ross, is the first to investigate the type and quantity of microplastics in New Zealand coastal environments.

Exposed beaches that are close to urban areas were found to have the highest concentrations of microplastics.  UC Senior Lecturer in Environmental Chemistry, Dr Sally Gaw who supervised the research project says:

“Plastics are used widely due to their properties. Appropriate use and disposal of plastics is important if we want to prevent microplastics accumulating in the oceans.”

The study involved a survey of different coastal environments around Christchurch and discovered using spectroscopy that white polystyrene fragments made up the majority of the microplastics found, followed by polyethylene and polypropylene.

Screen shot 2016-05-10 at 10.55.13 AM
Sediment samples from 10 coastal locations in the greater Canterbury region representing exposed-beach, estuarine and harbour environments in both urban and non-urban settings. Sample site 1 = Amberley beach; B, Banks Peninsula area. 2 = Akaroa; C, Christchurch City and Lyttelton Harbour. Urban areas coloured in black. Non-urban areas coloured in grey. Marine/estuarine environments coloured in white. 3 = New Brighton; 4 = South New Brighton; 5 = South Shore; 6 = Clifton; 7 = Estuary at Avon River mouth; 8 = Estuary at Heathcote River mouth; 9 = Corsair Bay; 10 = Governors Bay. Article

A recent international study reported that 99 per cent of the world’s seabirds will consume plastic by 2050.  Dr Gaw stresses that it is extremely difficult to remove plastics once they have been released into oceans.  In light of the new findings, Phil Clunies-Ross writes:

“We need to consider whether use of microplastics in consumer products like toothpaste and facial cleansers is appropriate. Other countries have recently banned the use of microplastics in consumer products. I would recommend that New Zealand implements a similar ban.”

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Suspected orange microbead and sand isolated from the exposed-beach coastline of New Brighton. Observed in A, optical; and B, UV fluorescence modes. Article

Explore the interactive website about microplastics, created by the lead researcher.

Featured image: CC flickr Antonio Foncubierta

Visit www.scimex.org for more research-related news from New Zealand and around the world.


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