http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0080466

Reisser J, Shaw J, Wilcox C, Hardesty BD, Proietti M, et al. (2013) 
Marine Plastic Pollution in Waters around Australia: Characteristics, 
Concentrations, and Pathways. PLoS ONE 8(11): e80466. 
doi:10.1371/journal.pone.0080466

Abstract
Plastics represent the vast majority of human-made debris present in the 
oceans. However, their characteristics, accumulation zones, and 
transport pathways remain poorly assessed. We characterised and 
estimated the concentration of marine plastics in waters around 
Australia using surface net tows, and inferred their potential pathways 
using particle-tracking models and real drifter trajectories. The 839 
marine plastics recorded were predominantly small fragments 
(“microplastics”, median length = 2.8 mm, mean length = 4.9 mm) 
resulting from the breakdown of larger objects made of polyethylene and 
polypropylene (e.g. packaging and fishing items). Mean sea surface 
plastic concentration was 4256.4 pieces km−2, and after incorporating 
the effect of vertical wind mixing, this value increased to 8966.3 
pieces km−2. These plastics appear to be associated with a wide range of 
ocean currents that connect the sampled sites to their international and 
domestic sources, including populated areas of Australia's east coast. 
This study shows that plastic contamination levels in surface waters of 
Australia are similar to those in the Caribbean Sea and Gulf of Maine, 
but considerably lower than those found in the subtropical gyres and 
Mediterranean Sea. Microplastics such as the ones described here have 
the potential to affect organisms ranging from megafauna to small fish 
and zooplankton.