86 per cent of Great Barrier Reef contaminated with microfibres


Surprising new research suggests about 86 per cent of the Great Barrier Reef is contaminated with microfibres.

One of Australia's lead marine research scientists said it was a big surprise to find so many microfibres in the ecosystem of the Great Barrier Reef.

Dr Frederieke Kroon from the Australian Institute of Marine Science found widespread contamination of the Great Barrier Reef, with more than 80 per cent of the samples analysed contaminated by microfibres. 

Dr Frederieke Kroon, AIMS Principal Research Scientist
Dr Kroon looking at a microfibre in the lab at AIMS

"I was surprised. When we first started the research, I thought it would be like finding a needle in the haystack," Dr Kroon said.

"The Great Barrier Reef is so remote, I thought it might be a little protected, but almost all the fish we tested were contaminated, 57 out of 60. It was surprising."

The presence of microplastics in our oceans is considered an emerging issue of international concern and this is the first study to examine the interaction between microplastic exposure and intake by marine organisms on the Great Barrier Reef.

In this 2016 study released today, Dr Kroon and her team collected 22 surface water samples and 60 Lemon damselfish at several inshore and offshore reef locations.  

Out of the 60 Lemon damselfish collected, 57 had marine micro-debris in their gastrointestinal tract - a total of 455 marine micro debris items were detected.

Dr Frederieke Kroon, Principal Scientist, AIMS
Dr Frederieke Kroon dragging for microplastics on AIMS research vessel RV Ferguson

The surface water samples reflected a similar contamination range - with marine micro debris detected in all of the 22 surface water tows conducted.  

More than half the items collected contained synthetic polymers - with polyester and nylon most abundant.

"The most significant finding I think is that we found more microfibres than microplastics, which sounds semantic, but it's important," Dr Kroon said.

"It points to what the main sources might be. In all the samples we analysed, more than 80 per cent contained microfibres. 

"The second most surprising finding is that the fish contamination is different from the water, which indicates some sort of selection process."

Scientists are looking at the possibility the fish may be avoiding or preferring microfibres of certain colours, possibly mistaking them for their natural food source. 

The most abundant colours of marine micro debris items were black, blue, white and red.

Dr Frederieke Kroon, Principal Research Scientist, AIMS
In the lab at AIMS, researchers working on microplastics.

Where is it coming from?

Previous research suggests that sewage effluent discharges are the main contributor to marine microfibre contamination.

This study suggests that sewage could be a potential source for micro debris inshore, but not at offshore reef locations. 

"We did modelling, looking at river flows and currents. They never went to the outer reefs," Dr Kroon said.

Now, the team are considering the possibility that the outer reefs are being contaminated by shipping traffic, or a new source - atmospheric deposition, where fibres may be dropping from the air.

A Damsel fish taken on the Great Barrier Reef.
A Damsel fish taken on the Great Barrier Reef.

"But this is unlikely," Dr Kroon said. "We need to do more work. It might be from other countries or sewage from shipping. Synthetic clothing ends up in sewage plants after going through the laundry process. That's where a lot of microfibres come from."

Unlike recent research which suggest microbeads from personal care products account for much of the microplastics found in European rivers, the microfibres found during this study appeared to be fragments resulting from the breakdown of larger items.

Even though the exact source is far from certain yet, research points towards the micro-debris starting off as furnishing, textiles, clothing and packaging material.

"They break down with the waves and turn into microparticles," says Dr Kroon.\ 

Rapidly emerging science  

This type of research is a rapidly emerging science, and the methodology used during the research is developing fast too.

The next step for Dr Kroon is to research the effects of microfibres and microplastics on the food chain, 

"We want to look at seafood species next, like scallops, prawns, to see what effect this might have on ourselves."

Finding out more about the source of the microfibres is also a priority.

The significance for the Great Barrier Reef

Dr Kroon hopes this research might have far-reaching effect.

She believes the more we know about what and how our oceans are polluted, the more that can be done to reduce the effects,

"Garbage has been found on islands in the Barrier Reef for decades, our research now shows that microfibres are also widespread," Dr Kroon said.

"We don't know yet what the effects are, but with all the reef has to endure, it's an additional stress the reef could do without. It's obviously man-made. Now we can start to pinpoint where things are coming from and reducing our use of them." 

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