http://www.csiro.au/Portals/Media/Plastic-on-the-coasts-is-ours.aspx

Plastic on the coasts is ours

The world's largest collection of marine debris information has
identified Australia's coastal rubbish is mainly plastic from Australian
sources.

15 September 2014

In a report released today, CSIRO scientist Denise Hardesty says her
team surveyed sites approximately every 100 km along the Australian
coastline.

?We found about three-quarters of the rubbish along the coast is
plastic,? she says. ?Most is from Australian sources, not the high seas,
with debris concentrated near cities.?

She says the density of plastic in Australian waters ranges from a few
thousand pieces of plastic per square kilometre to more than 40,000 pieces.