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Research highlights impact of plastic on marine environments
Scientists explore the sea floor and turtles's digestion to examine impact plastic is having on marine environments, Liam Cochrane reports.

Scientists have been telling us for some time that plastic rubbish is slowly choking our oceans, but new research shows it's even more of an international problem than previously thought.

Rubbish collects in huge, floating garbage patches in the middle of the world's oceans, and that's just what floats on the surface.

Scientists have been exploring the sea floor and the insides of turtles to examine the impact that our obsession with plastic is having on marine environments.

Liam Cochrane reports.
AUSKAR SURBAKTI, PRESENTER: Scientists have long warned that plastic rubbish is slowly choking the oceans. The new research shows it's even more of a problem than previously thought. Rubbish collects in huge floating garbage patches in the mitt middle the world's oceans but it's what's happening under the waves that is causing concern.

LIAM COCHRANE, REPORTER: At a Queensland research station, they check out the latest death of a turtle by plastic. This turtle was covered in barnacle; it was a sign that it could no longer dive to find food. Possibly due to plastic in its gut.

QAMAR SCHUYLER, UNIVERSITY OF QUEENSLAND: Just here is another indication the turtle has been starving.

LIAM COCHRANE: Schuyler's team have looked at every study since 1985 that measured just how much plastic sea turtles were digestion.

QAMAR SCHUYLER, : For particularly the green turtles and leatherback sea turtles the incidence of plastic ingestion or the risk of plastic ingestion for these turtles has increased dramatically over that time period.

LIAM COCHRANE: The long lives of sea turtles and their far ranging migrations make them good test cases.

Older turtles often mistake plastic bags for jelly fish while younger turtles are more likely to accidentally eat small pieces of white plastic, floating among their usual food fly supply. The results can be deadly.

QAMAR SCHUYLER: Plastic can lead to death for the sea turtles through one of two ways, it can impact the digestive system; make it impossible for the animal to process its food. It can also perforate the gastro-intestinal system and allow fluids to leak out into the stomach.

LIAM COCHRANE: Even if the plastic doesn't kill the turtles, it still cause damage. Some plastics are produced with harmful chemical s while others act as sponges for various toxins already in the ocean. These can lead to a build up of poison in the bodies of sea creatures. Qamar Schuyler says what's happening in the stomach of turtles are for those further up the food chain like humans

QAMAR SCHUYLER: Organisms as small as plankton are ingesting very tiny plastic particles. As largest organism s eat those organisms the amount of plastic s this their system accumulate s up the food chain.

LIAM COCHRANE: Since the 1950s the amount of plastic produce and thrown away has grown exponentially. According to a study by the European Council, plastic production has been increasing by an average rate of nine per cent since 1950. The peak production was in 2008, when 245 million tonnes of plastic was produced worldwide.

Some estimate it takes a plastic bag 500 years to fully breakdown but as plastic has only been around for 50 years these are only guesses. But thanks to a recent computer modelling techniques we now have a much better idea about how plastic debris circulates.

ERIC VAN SEBILLE, PHYSICAL OCEANOGRAPHER,UNSW: If you're using these buoys to get an estimate of what the plastic does in the ocean. We used the trajectory of these buoys to create this website drift where you can see if you throw your bottle in the ocean in Sydney how it would ends in the garbage patches.

LIAM COCHRANE: Scientist believe there are five big garbage patches in the oceans and a sixth patch in the Arctic.

ERIC VAN SEBILLE: A lot of us think about it as big islands of massive amounts of plastic but that is not true. Ice small pallets that drift or float on the surface of the ocean.

LIAM COCHRANE: But Erik van Sebille's research has found that these garbage patches are not isolated from each other.

ERIC VAN SEBILLE: What we learn from our computer stimulations is that the garbage patches are not the sink pole holes we thought they would be. They they're much more connected. So plastic does get into the garbage places but it moves from patch to patch. That means that the garbage problem is an international problem.

LIAM COCHRANE: It's also a problem that goes much deeper than floating plastic. The Monterrey bay aquarium Research Institute in the US sent unmanned submarines to if ocean floor and scientist s have painstakingly counted every piece of rubbish caught on film. Plastic made up 32 per cent of the rubbish they saw. From the depths of the sea floor to the garbage patches in the middle of our oceans, the problem of plastic is an ever growing one.

ERIC VAN SEBILLE: Even if we stop polluting tomorrow, these plastic won't go away. It will just stay there as a memory to what we've been doing over the last 50 years.
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