Saturday, September 08, 2012

Taking plastic seriously

Catalyst: Plastic Oceans - ABC TV Science

I was quite surprised by this story on Catalyst earlier this week.  The link contains the video and transcript.

The first surprise:  that the shearwater birds that live on Lord Howe Island appear to frequently die of stomachs absolutely loaded with plastic - which they apparently mistake for fish in the ocean. 

Lord Howe Island is in the middle of the South Pacific and has a tiny population - it's about the last place you would expect serious problems from marine plastic rubbish to arise.

The second surprise:  this part of the story, where they start talking about plastics that eventually break up into tiny pieces are still a major concern for their toxic effect:

Dr Jennifer Lavers
They have what I call the invisible toxic effect. It, it's less easy to detect but equally as scary.
The plastic itself inherently contains a wide array of chemicals that are used during the manufacturing and processes. When the plastic is put out into the marine environment and it floats around in the ocean for let's say ten or forty years it really does last forever, it basically acts like a little magnet or a sponge and it takes all the contaminates that are out there in the ocean environment that are really diluted in the ocean water and it concentrates it up, onto the surface.
Plastic itself has up to a thousand times a higher concentration of containments on its surface than the surrounding seawater from which it came. And when the animal, whether it's a turtle or a seabird takes that into their body those contaminants leach out into the blood stream and is incorporated into the tissues.

NARRATION
Jennifer Lavers collects and weighs plastic from dead birds and sends the feathers off for lab analysis. They reveal what contaminants are in the body.

Dr Jennifer Lavers
The flesh footed shearwater on Lord Howe Island is officially the world's most heavily contaminated seabird just from mercury alone. So the toxic threshold that's widely regarded around the world for birds is four point three parts per million. Anything above that four point three PPM is considered toxic to the birds. Well flesh footed shearwaters on Lord Howe Island are between one thousand and three thousand parts per million.
 The story indicates that the problems with broken down plastics getting into the food chain (right from the plankton level!) is just starting to be widely recognized in research.

It's a cause for concern, by the sounds... 

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