There is a young turtle in the ocean closest to you, learning to hunt. It is learning to judge the water's movement, the prey's agility and trying to capture itself enough sustenance to feed its growing body.
It spies a shadow lurking nearby, floating along, with wiggly bits around its edges. Is it a tender cuttlefish? A jellyfish? A tasty slab of wobbling seaweed?
It's actually a shopping bag, a bit of a balloon and a piece of your lunch wrap. It's plastic. And it floats in the ocean twisting and turning on the current just like an underwater creature that could be eaten.
There had been a clean-up of the island the previous two days, and they had taken out literally tonnes of plastic. And the next day it was still up to our ankles.
The CSIRO has recently reported that globally about one third of marine turtles have ingested plastic debris.
It might be one of those plastic bags—just like the one that I used to bring home the plastic carton of milk last night. You know, the carton type that has the handle already formed into the jug, with the plastic lid and the plastic ring on it, all encased in a plastic bag to transport it home.
Somehow, instead of being reused, recycled or disposed into a landfill site, that bag makes its way onto a street.
It rolls around on the ground full of air, lifts on a swirl of updraft, rips a little as it settles on a pedestrian crossing, is pushed to a creek by a burst of spring rain and then onto the sea where it moves seductively in the water, tempting a hungry young turtle.
When it is swallowed, the bag might plug the digestive system of the turtle, stopping anything from passing. The turtle starves.
It might take up room inside the stomach, reducing the turtle's ability to absorb nutrients or water. The turtle starves slowly.
It may get partially eaten away by acids in the digestive system, releasing toxic substances into the turtle's tissue.
Or perhaps a handle gets caught around the turtle's shell, creating drag and inefficiency, distorting the shell's growth over the coming months.
Maybe it gets caught in the gut with air in it, a watertight bubble that the turtle cannot pass as wind, inhibiting the turtle's ability to dive. And without diving, the turtle cannot hunt. It cannot evade predation or boat strike.
Clean Up Australia states that Australians use just under four billion plastic bags a year.
On a similar theme, CSIRO research indicates that between 5,000 and 15,000 turtles have been killed in the Gulf of Carpentaria after becoming ensnared by derelict fishing nets.
There is an ocean full of floating plastic debris out there, and it is estimated that eight million metric tonnes of new plastic debris enters the world's oceans every single year.
And plastic is turning up in remote areas, carried by ocean currents.
Dr Karrie Rose, an animal pathologist with the Australian Registry of Wildlife Health, has just returned from an expedition to the Christmas Island.
'Christmas Island is a beautiful place. And there is one beach on Christmas Island that has a notorious reputation as the most polluted beach in Australia,' she says.
'[The beach is] just on the cusp of the Pacific Gyre and it accumulates plastics and other rubbish a tremendous rate.
'So much so, that during our last trip to Christmas Island, there had been a clean-up of the island the previous two days, and they had taken out literally tonnes of plastic. And the next day it was still up to our ankles.
'It's not unusual for the crabs to be walking through plastic that would otherwise be up to your knees or my waist.
'You can see it coming in, just this sea of plastic hitting the beach on a regular basis.'
Dr Mark Browne, an ecologist from the University of New South Wales, says studies have looked at how turtle hatchlings make their run from a hatching site to the sea in environments like this.
'They're finding on areas where you actually have lots of litter, the crabs were able to hide behind the litter and actually mug the turtles as they go through: so [the litter] actually increased the rates of predation,' he says.
'That's why it's really important to understand the ecological processes that go on, because unless you understand that, you will be underestimating the problems each and every time.'
And that is not to say that exposure to plastic only impacts on wild animals.
'They've done intervention studies whereby they've actually got two groups of people and they've actually stopped one group of people having plastic for a week,' Dr Browne says.
'They've looked at chemicals in their blood which are associated with various reproductive abnormalities and various other issues, [and the levels] just drop off in the space of a week, just by not having packaged goods.'
An age of plastic
We have a tendency to define time periods of human history by materials: the iron age, the stone age and so on. Perhaps we are in the midst of the age of plastics, and if so, we're looking at a pretty durable timeline.
Since the 1950s, when mass production of plastics began in earnest, the world has embraced their ease of use and robustness.
In fact, the durability is both a blessing and a curse because plastics do not in general biodegrade. They break into sections, then scraps, then beads, then granules—they do not dissipate naturally into the environment.
Single-use plastic remains a relatively untested and un-legislated product (see for example, the non-compulsory Australian Packaging Covenant), even though plastic in the marine environment has been recognised by the Commonwealth Environment Department as a key threatening process under the Environment Protection and Biodiversity Conservation Act 1999.
And the plastics are not just shopping bags—they even include tiny synthetic threads off your clothing.
'These are the types of thing that you have in your household dust at home. When you open up the lint from the tumble dryer and you get rid of the stuff that's in there. That's the type of fibres we're finding in the environment,' Dr Browne says.
'They're actually the most abundant thing that we're finding.'
One of his research papers, which was published in 2011, indicated that a single synthetic garment can shed up to 1,900 micro-threads each wash.
'When we look at the fragments in the environment, over 65 per cent of them, in terms of number are made up of these tiny, tiny particles,' he says.
'In medical fields what they do is they put tiny medicines onto bits of plastic which you either inhale or ingest and they're designed to pass into your blood stream and deliver the medicine.
'The problem is that these plastics contain up to a million times greater quantities of persistent organic pollutants on the actual plastics themselves, and they can then de-sorb into the tissues of the organisms.
'The medical evidence we have for humans says that there's some pretty strong problems there.'
For example, artificial joints placed inside a body, with wear and tear, actually give off tiny little plastic particles.
'The types of microplastic that are formed through that are exactly he same type of microplastic we find in the environment. And that's known to cause inflammation, oxidative stress, fibrosis,' Dr Browne says.
'The work even that they've done for medical research has shown that when they put these particles of plastic with blood platelets, for instance, clotting can form.
'The difference is, in the medical field we know a lot about this because products can't go on sale until they're tested for safety.
'However, for products that are on the market, they don't have that level of testing of safety that goes on, so we only ever find out about problems a lot later. Hence why you find out about things like asbestos a lot later on.'
There is no doubt that plastic is a wonder material—enabling so many aspects of modern life. And activists like Roberta Dixon-Valk a co-founder of the #take3forthebeach initiative, are not calling for bans, but rather for more sensible use and disposal of plastic. Dixon-Valk's campaign aims to make picking up beachside litter a habit for all people.
'Take three is all about removing three pieces of rubbish wherever you are,' Dixon-Valk says, 'and by that simple gesture actually having a profound influence on the environment.'
This sentiment is echoed by Nardi Simpson, Yuwaalaraay woman and the Aboriginal Projects Officer at Taronga Zoo.
She says there are ties that bind everything in the environment to each other thing, and that humans cannot escape those ties, even if we desire to.
She tells a story where the first two people on earth were placed here with everything that they would need provided in nature.
The creator gave them trees and rocks and everything they needed would come from those materials. Water would fall over the rocks; trees would provide the fuel to burn in the fire.
'The woman or the man, has brought this cheeky fella [plastic], we brought him in,' Simpson says.
'He's now part of that law of connectedness, and that can make you feel no good.
'But then, in the problem also sits the answer: the first woman, the first man. Me and you.'
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